To examine striatal compartment-specific pathology and its relation to motor symptoms, we used immunohistochemistry to identify and measure the striosomes and matrix of 7-13-month-old YAC128 and wild type (WT) mice that were previously tested on motor tasks. Compared to WTs, 13-month-old YAC128s showed volume shrinkage in striosomes, and cell loss in both compartments. The percent cell loss was greater in striosomes than matrix. 
As soon as these changes are also seen in the striatal striosomes, in the framework of a dopamine dysregulation syndrome, stereotyped behaviours (punding) may occur (supposedly due to dorsal versus ventral striatal overactivity).
The striatum in the mammalian forebrain displays a unique mosaic organization (subdivided into two morphologically and functionally defined neuronal compartments: the matrix and the striosomes) that underlies important functional features of the basal ganglia.
BACKGROUND: The neostriatum, the mouse homologue of the primate caudate/putamen, is the input nucleus for the basal ganglia, receiving both cortical and dopaminergic input to each of its sub-compartments, the striosomes and matrix. METHODOLOGY/PRINCIPAL FINDINGS: The expression of CSPG-associated structures and PNNs with respect to neostriatal subcompartments has been examined qualitatively and quantitatively using double-labelling for Wisteria floribunda agglutinin (WFA), and the mu-opioid receptor (muOR), a marker for striosomes, at six postnatal ages in mice.
Strikingly, within the regions of remaining TH staining in the striatum, there was a greater loss of TH labeling in striosomes than in the surrounding matrix. The predominant loss of TH expression in striosomes occurred during the early postnatal period, when motor symptoms first appeared.
Excitatory inputs from the pedunculopontine nucleus interact with timed inhibitory inputs from model striosomes in the ventral striatum to regulate dopamine burst and dip responses from cells in the substantia nigra pars compacta and ventral tegmental area.
The striatum is divided into two compartments, the striosomes and extrastriosomal matrix, which differ in several cytochemical markers, input-output connections, and time of neurogenesis. Since it is thought that limbic, reward-related information and executive aspects of behavioral information may be differentially processed in the striosomes and matrix, respectively, intercompartmental communication should be of critical importance to proper functioning of the basal ganglia-thalamocortical circuits. Disinhibition of cells in the striosomes is further enhanced by inactivation of the protein kinase C cascade. We discuss in this review the possibility that MOR activation in the striosomes affects the activity of cholinergic interneurons and thus leads to changes in synaptic efficacy in the striatum..
A particular focus was the caudoputamen, which consists of patches (striosomes) and a surrounding matrix that is histologically uniform.
Medium-sized spiny projection neurons (MSN) in the head of the primate caudate nucleus are thought to have preferred dendritic orientations that tend to parallel the orientations of the striosomes.
The striosomes of the CN precommissural head and the postcommissural Put contained the greatest number of ChAT-ir interneurons. The intrastriosomal ChAT-ir neurons were abundant on the periphery of the striosomes throughout the striatum.
In this study we examined the long-term effect induced by MDMA on tyrosine hydroxylase (TH) and dopamine transporter (DAT) immunoreactivity in the striosomes and matrix compartments of mouse striatum. Interestingly, this effect was considerably more pronounced in striosomes than in the matrix. These data provide the first evidence that striosomes and matrix compartments of the mouse striatum have differential vulnerability to MDMA and that the long-term neurotoxicity induced by MDMA in mice is primarily associated with a loss of striosomal dopamine fibres..
Our results further showed that the density of neurons co-containing SP and ENK was three-fold higher in striosomes than in the matrix compartment.
The striatum is a heterogeneous mosaic of two neurochemically, developmentally, and functionally distinct compartments: the mu-opioid receptor (MOR)-enriched striosomes and the matrix. Preferential activation of the striosomes and persistent suppression of the matrix have recently been suggested to represent neural correlates of motor stereotypy. However, little is known concerning the physiological properties of the striosomes. We made patch-clamp recordings from medium spiny neurons in identified MOR-immunoreactive "dopamine islands" as striosomes in a slice preparation taken from transgenic mice expressing green fluorescent protein in tyrosine hydroxylase mRNA-containing neurons. Moreover, corticostriatal EPSCs were inhibited by MOR activation to similar extents in the two compartments, although inhibition of IPSCs was observed only in the striosomes.
striosomes were visualized in all striatal regions but the anterior two thirds of the CN tail. In the Put, other rings of tissue completely free of ENK labeling surrounded certain striosomes (clear septa).
Similar levels were observed in matrix and striosomes, and in enkephalin-positive and dynorphin-positive neurons.
In search for the anatomical basis for dystonia, we performed postmortem analyses of the functional anatomy of the basal ganglia based on the striatal compartments (i.e., the striosomes and matrix compartment) in XDP. Our study showed that in the XDP neostriatum, the matrix compartment is relatively spared in a mosaic pattern, whereas the striosomes are severely depleted.
In the limbic-prefrontal territory of the dorsal striatum, enkephalin inhibits the NMDA-evoked release of acetylcholine directly through micro-opioid receptors (MORs) located on cholinergic interneurons and indirectly through MORs of output neurons of striosomes. In this territory, we investigated the consequence of changes in dopamine transmission, bilateral 6-hydroxydopamine-induced degeneration of striatal dopaminergic innervation or cocaine (acute and chronic) exposure on (i) MOR expression in both cholinergic interneurons and output neurons of striosomes, and (ii) the direct and indirect enkephalin-MOR regulations of the NMDA-evoked release of acetylcholine. Expression of MORs in output neurons of striosomes was down-regulated in the 6-hydroxydopamine situation and either preserved or up-regulated after acute or chronic cocaine exposure, respectively. Accordingly, the indirect enkephalin-MOR control of acetylcholine release disappeared in the 6-hydroxydopamine situation but surprisingly, despite preservation of MORs in striosomes, disappeared after cocaine treatment. Showing that MORs of striosomes are still functional in this situation, the MOR agonist [ D-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin inhibited the NMDA-evoked release of acetylcholine after cocaine exposure.
Dopamine D(4) receptors (D(4) R) and mu-opioid receptors (MOR) are highly concentrated in the striosomes (islands) of the striatum, suggesting the existence of receptor-receptor interactions between them. The activation of D(4) R by the agonist PD168,077 (1 mg/kg) decreased MOR immunoreactivity (IR) in the striosomes 6 hours after drug treatment. The decreases of MOR IR in the striosomes suggest that D(4) R activation may reduce MOR signaling.
These TH+ cells were rarely found in the small TH-poor striosomes, most of them being embedded in the large TH-rich extrastriosomal matrix.
There is also variable degeneration of neurons in the two major neurochemical compartments of the striatum, the striosomes and the extrastriosomal matrix. To determine whether the phenotypic variability in Huntington's disease is related to this compartmental organization, we carried out a double-blind study in which we used GABA(A) receptor immunohistochemistry to analyse the status of striosomes and matrix in the brains of 35 Huntington's disease cases and 13 control cases, and collected detailed data on the clinical symptomatology expressed by the patients from family members and records. We report here a significant association between pronounced mood dysfunction in Huntington's disease patients and differential loss of the GABA(A) receptor marker in striosomes of the striatum.
Other functional compartments, such as striosomes, extrastriosomal matrix and matrisomes, also convey segregated projections. A greater number of large vessels and capillaries were found in the matrix compared to striosomes, and a likely correspondence exists between high-density arteriole envelopes and matrisomes.
This inhomogeneous labeling pattern appeared similar to one described in the cat with the unlabeled islands showing features of striosomes.
Thus, SP-only and ENK-only neurons make up the vast majority of striatal projection neurons in rats, the frequency of SP/ENK colocalizing striatal neurons is low in adult rats (3-4%), and SP/ENK colocalizing neurons primarily project to SNc but do not appear to be confined to striosomes..
Numerous striatal neurons are weakly immunoreactive for Reelin and these cells are preferentially located in striosomes.
According to our model, cannabinoids, opioids and ketamine may lead to hallucinations due to their promotional role in the LTD of cortical inputs to GABAergic spiny cells of striatal striosomes projecting to dopaminergic neurons, disinhibition of the lasts, and increase in striatal dopamine concentration..
The former coincided with the acetylcholinesterase-poor striosomes and the latter areas of dense projection with the extrastriosomal matrix..
The striatum itself is divided into two major compartments, the striosomes and the matrix, which differ by their neurochemical makeup and input/output connections. Here, neurons located in either striosomes or the extrastriosomal matrix in squirrel monkeys were injected with biotin dextran amine, and their labeled axons were entirely reconstructed with a camera lucida.
Some of these cells also occurred in the center and peripheral regions of the striosomes located in the head of the CN and in the Put. In the body and gyrus of the CN, the striosomes were largely devoid of these striatal interneurons.
We found no significant changes in the total area of striatum occupied by the calbindin-negative striosomes and no consistent changes in striatal calbindin mRNA.
To determine whether the general architecture of striatal vessels and mu opioid receptor-rich striosomes is similar, we investigated 3D reconstructions of coronal sections in 10 FVB mice. The sections were stained for striosomes using a mu opioid receptor antibody (MOR1). We used computerized procedures to detect striosomes and vessels and to calculate volume, number and colocalization of striosomes and vessels. The results showed a lattice-like pattern of striosomes similar to, and often surrounding, blood vessels. Furthermore, co-localization calculations suggested that the striosomes are more vascular than the matrix. Vessel volume was 5.0+/-1.3% per microm3 in striosomes versus 3.6+/-0.9%microm3 in matrix (p=0.01). In addition, the greater vascularity of the striosomes compared to the matrix suggests a unique function of this compartment in relation to humoral signals and neurotropic drugs..
In search for the anatomical basis for dystonia, we performed postmortem analyses of the functional anatomy of the basal ganglia based on the striatal compartments (ie, the striosomes and the matrix compartment) in XDP. Here, we provide anatomopathological evidence that, in the XDP neostriatum, the matrix compartment is relatively spared in a unique fashion, whereas the striosomes are severely depleted.
Mu opioid receptors are densely expressed within rat striatum and are concentrated in anatomically discrete patches called striosomes. We examined the extent of G protein coupling by mu opioid receptors in rat brain during development, focusing on striosomes within the striatum because of receptor density.
We have found that repeated stimulation of the rat prelimbic cortex with picrotoxin (0.25 microg/0.25 microl, five injections on alternate days followed by 7-day withdrawal) contributed to increase c-Fos protein expression in the striosomes of the dorsolateral striatum, while producing the opposite effect in the matrix compartment, after a single exposure to cocaine (25 mg/kg).
In turn, the striosomes are anatomically connected through re-entrant loops with limbic prefrontal and allocortical structures, such as anterior cingulate cortex, orbital frontal cortex, and basolateral amygdala, all of which play a part in stimulant-induced reinforcement and relapse to drug-taking.
Both the stereotypic response to METH and the associated predominant activation of neurons located in striosomes require D2-receptor expression.
(3) Substance P distribution was 'reversed' in dopamine depleted striatum: striosomes, which normally express higher levels of substance P, showed decreased expression, whereas substance P expression was up-regulated in the matrix.
In primates, immunostaining for both GAD65 and GAD67 was much more intense in striosomes than in the surrounding matrix. The GAD immunostaining was more uniformly distributed in the rat striatum, which did not display GAD-rich patches that corresponded to MOR-positive striosomes. These results reveal that GAD65 and GAD67 are faithful markers of striosomes in primates but not in rodents.
RESULTS: Chronic clozapine induced clustered FosB/DeltaFosB expression within striosomes of the caudate-putamen. This pattern was due to increased levels of FosB/DeltaFosB in striosomes within the ventrolateral caudate-putamen and reduced levels of basal FosB/DeltaFosB in the matrix in the entire caudate-putamen. In contrast, chronic haloperidol increased FosB/DeltaFosB equally within the matrix and striosomes throughout the entire caudate-putamen.
These studies emphasize the functional importance of the compartmental organization of the striatum and raise the possibility that differential activation of striosomes is related to the severity of the expressed stereotypies and sensitized responses..
As expected, based on the presence of micro-opioid receptors in striosomes, beta-funaltrexamine (0.1 nM, 10 nM and 1 microM) enhanced the NMDA (1 mM+10 microM D-serine)-evoked release of ACh in striosome-enriched areas but not in the matrix. The selective micro-opiate agonist, [ D-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin (1 microM, coapplied with NMDA), was without effect on the NMDA-evoked release of ACh but abolished both dopamine-dependent (morning) and dopamine-independent (afternoon) responses of beta-funaltrexamine (10 nM and 1 microM).Therefore, in the limbic territory of the striatum enriched in striosomes, the micro-opioid-inhibitory regulation of ACh release follows diurnal rhythms.
Studies on the mechanisms controlling motor stereotypies have focused on the role of dopamine in modulating the activity of basal ganglia neuronal circuits, and recent results demonstrated that stereotypic motor responses characteristic of psychomotor stimulant sensitization correlate with an enhanced activation of neurons located in striatal striosomes that substantially exceeds that of the surrounding matrix. The stereotypic response of wild-type and D(3) mutants correlates with a predominant activation of neurons located in striosomes.
In the caudate nucleus, haloperidol induced staining was more marked in the striosomes than the matrix.
It follows from the model that the negative feedback loops can held the activity of a striatal output cells at the stable level due to recurrent activation by endogenous opioids of delta receptors on striatopallidal cells, mu and kappa receptors on striatonigral cells of striosomes and matrix, respectively, and subsequent suppression of the efficacy of corticostriatal inputs.
In fact several sub-populations of MSNs can be distinguished according to the striatal compartment (striosomes and matrix) to which they belong, their afferents and their sites of projection, their biochemical markers and their morphologies.
This increase was heterogeneous with increased expression within the striosomes compared to matrix compartments of the striatum.
In the mature striatum, Foxp2 expression was maintained in striosomes, although its expression level was reduced.
In the putamen intense labelling of the striosomes was observed; most of the medium-sized neurons in the caudate-putamen were weakly labelled and many large neurons of the striatum were conspicuously stained.
The mammalian striatum is a heterogeneous structure characterized by striosomes and matrix.
In addition, increased BDNF immunoreactivity was found in fibers of many projection targets of the basolateral amygdala--the central extended amygdala, olfactory tubercle, medial nucleus accumbens, and in small zones resembling striosomes in the dorsal medial striatum.
The three types of striatal NK1R-positive neurons were preferentially localized in the peripheral region of the striosomes, which were identified by their intense immunostaining for the limbic system-associated membrane protein.
The effects of this selective cell targeting encompassed alterations in both behavioral and neural responses to dopaminergic stimulation, including altered patterns of early-gene response in striosomes and matrix.
RasGRP-immunoreactivity was also observed in the matrix-like compartment surrounding these patches/striosomes but appeared later in development and was always weaker than in the patches. At the ultrastructural level, immunogold labeling of RasGRP was confined to the cell bodies and dendritic shafts of these output neurons.We conclude that the prominent expression of RasGRP in striosomes may be of significance for diacylglycerol signaling in the striatum, and could be of importance for the processing of limbic-related activity within the basal ganglia..
Cannabinoid-mediated rise of dopamine release might be a result of a decrease of dopamine neuron inhibition by striatonigral cells of striosomes.
The mammalian striatum, a subpallial area, consists of two compartments (patches/striosomes and matrix) that differ in their neuronal birth dates, connectivity, neurochemistry, and molecular make-up. For example, members of the cadherin family of adhesion molecules (cadherin-8 and OL-protocadherin) are differentially expressed by the striosomes and the striatal matrix.
These receptors were expressed in cell bodies and in the neuropil and were heterogeneously distributed among different striatal compartments, being more abundant in striosomes than in the matrix. The prominent immunoreactivity observed in the striosomes indicates that integrative processes involved in D4-mediated limbic behaviours occurs through the striosomes rather than accumbens, whereas the motor behaviour is based in the striatal matrix..
Using a microsuperfusion method in vitro, the effects of the NK1, NK2, and NK3 tachykinin receptor antagonists SR140333, SR48968, and SR142801, respectively, on the NMDA-evoked release of [ 3H]-acetylcholine were investigated after both acute and chronic suppression of dopamine transmission in striosomes and matrix of the rat striatum. Therefore, in the matrix but not in striosomes, the acute or chronic suppression of dopamine transmission unmasked the facilitatory effects of endogenously released substance P, neurokinin A, and neurokinin B on the NMDA-evoked release of [ 3H]-acetylcholine.
To determine whether these compartments are distinguishable functionally, we used [ 14C]deoxyglucose metabolic mapping in the rat and tested whether neutral behavioral states (free movement, gentle restraint, and focal tactile stimulation under gentle restraint) were associated with regions of high metabolic activity in the matrix, in striosomes, or in both.
Autoradiographic competition experiments were performed with these antagonists in human brain regions where (+/-)-[ (125)I]DOI labels almost exclusively 5-HT(2A) receptors (frontal cortex and striosomes).
Some dorsal tier SNc axons also project to both striosomes and matrix. Other dorsal tier SNc axons, as well as VTA axons, innervate the ventral striatum and send collaterals to striosomes lying ventrally in the dorsal striatum or to the ventral sector of the subcallosal streak (SS). Ventral tier SNc axons arborize principally in striosomes, but some ramify in both compartments or in striosomes and the SS.
Muscarinic m1 labeling was dramatically more intense in the striatal matrix compartment in juvenile monkeys but more intense in striosomes in the adult caudate, suggesting that m1 expression undergoes a developmental age-dependent change.
In mammals (125)I-DOI binding shows a patchy density distribution in the striatum, being more dense in striosomes than in surrounding matrix.
At rostral striatal levels, numerous small TH-poor zones embedded in a TH-rich matrix correspond to calbindin-poor striosomes and calbindin-rich extrastriosomal matrix, respectively. At caudal striatal levels, in contrast, striosomes display a TH immunostaining that is more intense than that of the matrix.
5-HT(1A) receptor density of control animals was high in the hippocampus, notably in the CA1 field and also in the raphe nuclei, and much lower in the striatum, where 5-HT(1A) receptors showed a patchy distribution which corresponded to striosomes with poor calbindin immunostaining.
In addition to the classic striosomes/matrix compartmentalization, the striosomal compartment itself is composed of a core and a peripheral region, each subdivided by distinct subsets of striatal interneurons.
Here we suggest a three-pathway model of the basal ganglia that takes into consideration the fundamental division of the striatum into striosomes and extrastriosomal matrix.
Nigral dopaminergic neurons receive limbic input directly as well as indirectly through the striosomes in the striatum.
It has been hypothesized that the anatomical framework for the selective response of these neurons is organized in the projections from some paralimbic areas in the frontal lobe to the striosomes of the caudate nucleus, which are also directly connected with the dopaminergic neurons of the SNC.
We then used a gene induction assay to measure the functional activation of neurons in the neurochemically distinct compartments of the striatum, the striosomes and the extrastriosomal matrix. The amount by which activation in the striosomes exceeded activation in the matrix predicted the degree of motor stereotypy induced by the drug treatments.
The adult striatum is composed of interlacing compartments known as patches (striosomes) and matrix, which differ with respect to a host of architectonic, biochemical and developmental parameters.
The dopamine denervation resulted in distinct alterations in GluR1 distribution: (1) GluR1 protein expression was markedly increased in caudate and putamen, and this was most pronounced in the striosomes; (2) GluR1 protein was altered minimally in subthalamic nucleus; (3) expression of GluR1 was down-regulated in the globus pallidus by 63% and in the substantia nigra by 57%.
In this study, to assess further the suitability of 3NPA-induced striatal lesions as a model for HD neuropathology, we examined the effects of striatal lesions induced by the systemic administration of 3NPA on the binding of 3H[ -CP55,940 to pre- and postsynaptic cannabinoid receptors in striatum, globus pallidus, entopeduncular nucleus and substantia nigra pars reticulata and also the effect of 3NPA-induced striatal lesions on the binding of 3H[ -DAMGO to mu-opioid receptors in striatal striosomes.
Furthermore, Reelin protein is differentially concentrated in the two distinct compartments showing a mosaic-like fashion in the early postnatal period: the compartments of heightened CR-50-immunolabeling correspond to so-called "dopamine islands" (i.e., developing striosomes) visualized by tyrosine hydroxylase (TH)-immunostaining.
The contribution of endogenously released dopamine, GABA and its co-transmitters, substance P (SP) and neurokinin A (NKA), to the control of the evoked release of acetylcholine was investigated in vitro in the striosomes and the matrix of the rat striatum under various modalities of NMDA receptor stimulation (NMDA 50 microM or 1 mM without or with 10 microM D-serine). (2) In striosomes, the dopamine-dependent inhibitory effects of SP and NKA on the evoked release of acetylcholine only occurred when D-serine was co-applied with 50 microM or 1 mM NMDA. In the presence of D-serine, and depending on the NMDA concentration, the facilitatory regulation of GABA was reduced (matrix) or suppressed (striosomes).
Strongly labeled cell clusters that appeared in the medial and central caudate-putamen were preferentially located within calbindin-poor, mu-opioid receptor-rich striosomes, whereas the lateral area displaying FosB activation encompassed both striosomal and matrix domains.
A neural model explains the key neurophysiological properties of these cells before, during, and after conditioning, as well as related anatomical and neurophysiological data about the pedunculopontine tegmental nucleus (PPTN), lateral hypothalamus, ventral striatum, and striosomes. The model proposes how two parallel learning pathways from limbic cortex to the SNc, one devoted to excitatory conditioning (through the ventral striatum, ventral pallidum, and PPTN) and the other to adaptively timed inhibitory conditioning (through the striosomes), control SNc responses.
These results confirm the presence of 5-HT2A receptors in human striosomes and in those areas where [ 3H]ketanserin presented a high nonspecific binding, and they highlight the advantage of using [ 3H]MDL100,907 to visualize these receptors..
The striosomes were delineated by using the following markers: acetylcholinesterase (AChE), enkephalin (ENK), substance P (SP), calbindin-D28k (CB), parvalbumin (PV), calretinin (CR), limbic system-associated membrane protein (LAMP), choline acetyltransferase (ChAT), tyrosine hydroxylase (TH), and NADPH-diaphorase. Comparisons were made between striosomal boundaries, as outlined by each marker applied on adjacent sections, and particular attention was paid to possible variations in the chemical features of striosomes along the rostrocaudal extent of the striatum. The main findings of this study are as follows: 1) the striosomal compartment is composed of two chemically distinct domains: a core and a peripheral region; 2) the core is largely devoid of CB and displays a less intense staining for ENK and LAMP than the peripheral region; 3) although striosomes are largely devoid of AChE, the activity of this enzyme is slightly higher in the core than in the peripheral region; 4) the core and peripheral regions are weakly stained for PV and intensely stained for SP; 5) ChAT-, CR- and NADPH-diaphorase-positive neurons are preferentially distributed in the peripheral region; 6) at rostral striatal levels, striosomes are largely devoid of TH, whereas the inverse is true caudally; and 7) at caudal striatal levels, the peripheral region of striosomes is intensely stained for CB and ChAT. These results demonstrate that the striosomes in human display a strikingly complex and heterogeneous chemical architecture..
A marked differential vulnerability to DNA damage at this time was observed in two striatal compartments, the striosomes, identified as regions of dense [ (3)H]naloxone binding, and the extrastriosomal matrix: the great majority of labeled cells were found in the extrastriosomal matrix and extremely few were seen in the striosomes. This preferential distribution was not due to premature cell death in the striosomes which contained numerous unlabeled neurons. The results suggest a greater vulnerability of neurons in the matrix, versus the striosomes, to early excitotoxin-induced DNA damage in rat striatum..
Binding is absent from the striosomes, which were identified by mu-opioid receptor immunostaining.
In the striatum, immunoreactivity was more intense in striosomes than in the matrix.
A remarkable decrease of the volume of internal capsule and striosomes, a moderate reduction of that of corpus callosum and no changes of the volume of external capsule and of white matter of hippocampus were also observed in SHR.
These authors described in the human striatum, as well as in the cats and primates, zones poorly stained for the enzyme acetylcholinesterase, which they termed striosomes, that lie in more intensely stained matrix. DEVELOPMENT: The results of many studies performed in different species in the last twenty years have indicated that the chemical heterogeneity of striatum is more complex than the simple subdivision into striosomes and matrix compartments. Furthermore, the most recent study of the distribution of a wide variety of neurochemical markers in the striosomal compartment of the human striatum, has revealed that the striosomes are themselves heterogeneous, being composed of a central core and a peripheral region.
A reduction of volume of frontal cortex gray and white matter as well as of striosomes and of gray matter of hippocampus was found in SHR.
A distinct striosomal patterning appeared after chronic apomorphine administration in ventromedial part of the denervated striatum with a down-regulation in the matrix and relative enhancement in striosomes.
With respect to striosome-matrix compartmentalization, there was no complete segregation, although D1 and D3 receptors were concentrated in striosomes, whereas D2 receptors and uptake sites showed higher density in the matrix.
Autoradiographic labeling of these receptors by the selective antagonist [ 3H]MDL 100,907 and saturation experiments with cortical membranes revealed: (1) a new localization of these receptors in the external field of striatum (possibly in striosomes); (2) regional variations in adaptive changes in the density of 5-HT2A receptors in 5-HT(-/-) mutants (-30-40% in the claustrum, cerebral cortex and lateral striatum; no significant change in the striatum core) as compared to wild-type mice..
Within the striatum, binding was noticeably higher in both the nucleus accumbens and acetylcholinesterase-deficient striosomes, while being undetectable in the subthalamic nucleus and very low in both the ventroanterior and ventrolateral thalamic nuclei.
Both treatments similarly reduce the NMDA-evoked release of [ 3H]-acetylcholine, this effect being more pronounced in striosomes than in the matrix. Moreover, the superfusion with BSA was shown to enhance the release of [ 3H]-dopamine (formed from [ 3H]-tyrosine), this effect being of larger amplitude in striosomes than in the matrix. These results indicate that arachidonic acid endogenously formed under weak stimulation of NMDA receptors contributes to the regulation of the evoked release of [ 3H]-acetylcholine by facilitating GABAergic transmission and that this process is more important in striosomes than in the matrix..
The coupling of striatal dopamine D1 receptors to c-fos transcription exhibit all-or-none regional and ontogenic differences: the D1 agonist SKF 38393 fails to induce c-fos expression in the striatum, except during the early postnatal period in the striosomes, or in the caudal extremity of the striatum in adult animals.
These results suggest that under potent stimulation of N-methyl-D-aspartate receptors, endogenously released substance P and neurokinin A (or related tachykinins) regulate differently the N-methyl-D-aspartate-evoked release of [ 3H]acetylcholine in striosomes and in the matrix.
Four types of alpha1 subunit immunoreactive neurons were identified in the baboon striatum: the most numerous (75%) were type 1 medium-sized aspiny neurons; type 2 (2%) were large aspiny neurons with an indented nuclear membrane located in the ventral striatum; type 3 neurons were the least numerous (1%) and were comprised of large neurons in the ventromedial regions of the striatum; and type 4 (22%) neurons were medium to large aspiny neurons located in striosomes.
Histological sections of the mammalian striatum reveal a "matrix" that is histochemically distinguishable from patches, or "striosomes". Rats acquired and maintained bar-pressing responses that were contingent on stimulation through electrodes making contact with striosomes/patches more reliably than animals with electrodes terminating exclusively in the matrix.
In the ventral region of the striatum at more caudal levels, however, both drugs induced staining in patches which were in register with the opiate receptor rich striosomes.
The same D1 stimulus elicited (i) transient phosphorylation (striosomes, the nucleus accumbens, the fundus striati, and the bed nucleus of the stria terminalis; and (iii) prolonged phosphorylation (up to 4 hr or more) in cellular islands in the olfactory tubercle.
The labeling pattern is heterogeneous and more intense in the striosomes than in the matrix.
Autoradiography was used to test the idea that m4 receptors are localized preferentially in the striosomes of the cat striatum. Non-m1 receptors were distributed equally in striosomes and matrix, indicating that striatal neurons with m4 receptors are in both compartments.
At striatal level Bcl-2-positive neurons were strictly confined to calbindin-poor striosomes, which are specifically innervated by limbic cortices.
Lateral to medial and anterior to posterior gradients in transporter density were established early during development, and there was also an early concentration of transporter in striosomes that became difficult to identify by day 15.
Comparison with adjacent sections processed for the calcium binding protein calbindin, indicated that quinpirole pretreatment specifically suppressed staining in the matrix compartment of the striatum while tending to potentiate it in the striosomes, resulting in an extremely patchy pattern of labeling.
Before birth, the neurons expressing enkephalin and D1R mRNAs were preferentially distributed in the matrix and in the striosomes, respectively, while the neurons expressing D2R mRNA did not display a preferential localization. D2R mRNA was heterogeneously distributed in the whole striatum with high signals located both in the striosomes and the matrix.
N-Methyl-D-aspartate responses were concentration-dependent, but the 1 mM N-methyl-D-aspartate response was higher in striosomes than in the matrix. The co-application of D-serine (10 microM) enhanced the 10 microM N-methyl-D-aspartate response in both compartments, but reduced those induced by 1 mM N-methyl-D-aspartate, this reduction being higher in striosomes. The blockade of dopaminergic transmission with the D2 and D1 dopaminergic receptor antagonists, (-)-sulpiride (1 microM) and SCH23390 (1 microM), was without effect on the 50 microM N-methyl-D-aspartate-evoked release of [ 3H]acetylcholine, but markedly enhanced the 1 mM N-methyl-D-aspartate+D-serine-evoked response in striosomes and to a lesser extent in the matrix. Disinhibitory responses of similar amplitude were observed not only in striosomes but also in the matrix when (-)-sulpiride was used alone, while SCH23390 alone enhanced the 1 mM N-methyl-D-aspartate+D-serine response only in striosomes and to a lower extent than (-)-sulpiride. They also show that the stimulation of D1 receptors can either reduce (striosomes) or enhance (matrix) this response, since in the latter case the effect induced by the combined application of the D1 and D2 receptor antagonists was smaller than that observed with the D2 receptor antagonist alone.
In the dorsal putamen, ChAT-staining was less intense, and striosomes were delineated primarily by unstained fiber bundles.
In both the adult and perinatal striatum, D2 receptor densities were greater in the putamen than in the caudate, and both D1 and D2 receptor densities were modestly enriched in caudate striosomes compared with the matrix.
The intensely stained neurons are concentrated within the striatal striosomes, as defined by calbindin-D28K staining.
Finally, at the light microscopic level, 5'-nucleotidase activity displays a dense neuropil staining which identifies topographic sub-units of certain parts of the nervous system, such as the striosomes of the basal ganglia, ocular dominance columns of the visual cortex and parasagittal bands of the cerebellum..
During infancy, the pattern of CB expression changed from one of CB-rich patches to one of CB-poor striosomes and rich matrix.
The dorsal striatum has been described as containing two compartments, striosomes and matrix, while the ventral striatum is thought to have a more complex, multi-compartmental organization.
The striatal matrix compartment is markedly enriched with calbindin while striatal patches (striosomes) display a calretinin-rich neuropil.
In striosomes, the reducing effect of [ Pro9]substance P and the enhancing action of septide on the N-methyl-D-aspartate response were respectively blocked in the presence of low and high concentrations of RP 67580, while the stimulatory effect of septide on the N-methyl-D-aspartate response in the matrix was prevented with both concentrations of the neurokinin-1 receptor antagonist.
From week 20 of fetal life, D1R gene expression developed in the matrix neurons as well, thus leading to an even D1R mRNA expression throughout striosomes and matrix compartments at birth. High DYN mRNA expression was restricted to the striosomes, whereas high D1R mRNA expression was present in the whole striatum.
By contrast, in the core of the striosomes, SPR labeling was sparse and SP staining intense.
Comparison with adjacent sections stained for the calcium binding protein calbindin indicated that the patches of amphetamine induced labeling corresponded to the calbindin-poor striosomes.
The striatum developed later, showing earlier growth in the anterior and dorsolateral regions, with early localization in both striosomes and a subcallosal streak.
The zone of densely packed TH-positive neurons in the substantia nigra that is likely to be the origin of innervation to striosomes in the caudoputamen disappears between P21 and adulthood.
These findings suggest that, in the sensorimotor striatum, motor and somatosensory inputs may undergo different proportions of local processing at the borders of their distribution zones (striosomes and matrisomes)..
These protein-rich zones are in register with striosomes, as visualized on adjacent sections immunostained for calbindin.
Under the light microscope, striatal neurons appeared to be less strongly immunoreactive for calcineurin in the striosomes than in the matrix compartment.
These patches corresponded to striosomes, identified by immunostaining for calbindin-D28 K in adjacent sections. Calretinin-positive fibers fill striosomes/patches in the caudoputamen and in the lateral nucleus accumbens and avoid them in the medial nucleus accumbens..
Positive symptoms could also be due to a secondary hyperdopaminergia, since a part of striatum, the striosomes, connected with limbic system, control the activity of dopaminergic neurons.
These areas jointly innervated striosomes in the anterior and ventromedial striatum, mainly in the caudate nucleus. striosomes in the dorsolateral striatum were never labeled. Most of these prefrontal inputs were also patchy, and many of the patches (matrisomes) were selectively paired with nearby striosomes. The highly fractionated organization of prefrontal inputs to striosomes and matrisomes could form a template for computational networks in the striatum that redistribute prefrontal corticostriatal inputs to serve in context-dependent behavioral planning..
In these studies we used in vivo electrochemical recording to examine the effect of ip cocaine on exogenous DA clearance in the medial and lateral dorsal striatum with respect to both DA transporter binding sites and electrode localization to striosomes or matrix.
Results of previous studies have suggested differences in the regulatory mechanisms in striatal striosomes and matrix following interruption of dopaminergic input to the striatum by MPTP in the monkey. Furthermore, the effect was more robust in the striosomes than in the matrix, thus providing evidence for differential functional and/or metabolic regulation in striatal striosomes and matrix in parkinsonian syndromes..
(2) In some regions of the rostral half of the caudate-putamen complex, the staining for zinc appeared to follow the well-known striatal patches (striosomes)/matrix organization.
In the striatum, beta-galactosidase activity was restricted to neurons within the matrix and was not detected within striosomes. Furthermore, expression of the transgene to neurons within the matrix of the striatum, but not the striosomes suggests that expression of the D1A receptor may be regulated differently within these areas..
The induction of Fos-like protein was mainly in striosomes and a medial compartment next to the ventricular zone, whereas Fra-like protein was induced in the striatal matrix as well.
In the caudate and putamen, clusters of cells expressing high levels of dynorphin and preprotachykinin messenger RNAs were clearly in register with the striosomes.
The striatum is composed of two compartments arranged as a mosaic, the striosomes (patches) and the matrix, which differ in their neurochemical and neuroanatomical properties. This compartmentalization of response suggests that there are functionally distinct molecular signalling pathways in striosomes and matrix. administration of the cannabinoid agonist CP55,940 and demonstrates a selective induction of this protein within the striosomes 2 h after drug administration.
Moreover, while MEnk-positive striosomes was readily detected in the putamen of normals and sporadic ALS patients, there was significant reduction in MEnk immunoreactivity, and no evidence of striosomal organization in the putamen of MND/BIs patients.
Pockets of lower 125I-NGF binding corresponding to acetylcholinesterase-poor striosomes were detected in the striatum of control subjects and patients with Parkinson's disease or progressive supranuclear palsy.
Binding of [ 125I]epidepride to D3-like receptors was negligible in the dorsal striatum but was concentrated in islands of dense binding in the nucleus accumbens and ventral putamen that aligned with acetylcholinesterase-poor striosomes.
The morphology of the parvalbumin-immunoreactive neurones varied between the striosomes and matrix; those in the matrix were smaller and possessed dendritic arborisations that were relatively uniform, whereas those in the striosomes were generally more extensively stained and possessed a greater variation in their dendritic branching patterns. The dendrites frequently crossed the boundary between the striosomes and matrix.
We have examined the distribution of leucine enkephalin (LENK) and substance P (SP) immunoreactivity in relation to striosomes defined by calbindin-D (CABD) staining in alternate 70 microns serial sections from the human caudate nucleus. In contrast, in the ventral caudate and nucleus accumbens, LENK-poor zones matched CABD-defined striosomes. SP-rich zones in dorsal caudate and SP-poor areas in the mid-ventral region overlapped striosomes. In the ventromedial sector, the SP staining pattern was complex and did not consistently correlate with striosomes.
High levels of labeling were detected in the thalamus, striosomes of the caudate-putamen, globus pallidus, and brain regions involved in nociception, arousal, respiratory control, and, possibly, addiction.
The localization of their binding sites in the dorsal striatum is very similar to that of striosomes, as visualized by acetylcholinesterase histochemistry or [ 3H]flunitrazepam labelling. The density of [ 125I]DOI binding sites over striosomes presents large variations, which can neither be correlated with parameters such as age, gender and post-mortem delay nor with the effects of neurodegenerative disorders, with the exception of Huntington's disease, at late stages of the disease. The drug binding profile of [ 125I]DOI binding sites in the striosomes is identical to that of matrix binding sites.
The portrayal by Wilson, in 1925, of the striatum as a simple homogeneous structure has been replaced by the recognition, based on staining characteristics, connectivity, and function, that the neostriatum is compartmentalized into striosomes, matrisomes, and matrix compartments.
Light microscopic observation showed neurons immunoreactive for CaM-kinase II to be less densely distributed in the striosomes than in the matrix compartment.
The temporary divergence may increase lateral interactions between sensorimotor matrisomes, as well as between matrisomes and striosomes.
Cytoarchitectonically defined cell-dense islands and regions of low acetylcholinesterase reactivity referred to as striosomes have been regarded as equivalent markers of the non-matrix compartment in the neostriatum. We examined islands and striosomes in adjacent sections to determine the degree of correspondence between the two neostriatal compartmental markers. Islands are aggregated centrally within the caudate, whereas striosomes are located throughout the entire nucleus, including the dorsolateral and ventromedial sectors. Moreover, even within the central sector, striosomes are more prevalent than islands. The present quantitative analysis suggests that islands may be further characterized as acetylcholinesterase-poor since the vast majority of islands co-localize with striosomes. However, due to the fact that striosomes are more numerous and more widely distributed throughout the neostriatum, less than a third of all striosomes are coincident with islands in adjacent sections. The percentage of striosomes which are aligned with fenestrations in the prefrontal projection is also quite high; however, because more striosomes than islands are found within the prefrontal terminal domain, some striosomes that fit within terminal-free zones do not have corresponding islands. These results indicate that islands and striosomes are not entirely equivalent compartmental markers and further suggest that contemporary, two-compartment models may not adequately represent the heterogeneity of the neostriatum..
Despite the relatively unfeatured cytoarchitecture of the striatum, this large subcortical region has been found to have a modular macroscopic substructure comprising the neurochemically distinct striosomes and matrix, and, within the matrix, patchy input and output arrangements called matrisomes. The data were unequivocal in suggesting that many spiny neurons, whether near striosomes or not, have dendritic arbors with preferred orientations along a diagonal axis running from rostral, dorsal, and medial to caudal, ventral, and lateral. This axis corresponds to the orientations of many striosomes and matrisomes in the squirrel monkey's caudate nucleus. We therefore suggest that the primate striatum is characterized not only by a macroscopic organization dividing it into striosomes and matrisomes, but also by a microscopic architecture observed by the dendritic arbors of many of its projection neurons.
In the experiments described here we analyzed the dendritic fields of spiny neurons in the squirrel monkey striatum and plotted their orientations with respect to the borders between striosomes and matrix. Other medium spiny neurons, however, in both striosomes and matrix, had dendrites that crossed from one compartment into the other. For a subpopulation of spiny neurons in striosomes and matrix, inputs to one compartment could have a direct influence on output cells of the other..
Oxotremorine, a non-selective muscarinic agonist, induced Fos immunoreactivity in the striatum with a large predominance in striosomes (mostly in enkephalinergic neurons), in layers 4 and 6 of the cortex, and also in the piriform cortex and septum.
There was also a 41% reduction in the number of striosomes, and a small (14%) but significant decrease in the mean area of individual striosomes.
Circumscribed zones of enhanced IP3R, PLC beta, and PLC gamma immunoreactivity appeared in a background of generally weaker staining, and these zones corresponded to striosomes as identified by calbinidin D28k and substance P immunostaining in adjacent sections. Thus, the richest representation of the phosphoinositide system in the primate striatum appears to be in striosomes. These observations demonstrate that the phosphoinositide second messenger system is selectively enhanced in neuronal subsystems of the basal ganglia, including striosomes, and suggest that signaling by phosphoinositide pathways elicits discrete effects on input-output processing by the basal ganglia..
The glycoprotein 5'-nucleotidase is a cell surface phosphatase and represents a new marker for striosomes in the adult rat caudoputamen. This compartmental pattern persisted thereafter, so that in adult animals, in all but the caudal caudoputamen, zones of enhanced 5'-nucleotidase staining were restricted to calbindin-D28k-poor striosomes. After the second postnatal week, most of the caudoputamen was stained, and in adult mice only rostral striosomes expressed low 5'-nucleotidase activity.
In the caudate nucleus, D1R mRNA was concentrated in calbindin-poor striosomes where dense grain clusters were seen overlying the majority of medium-sized neurons (diameter approximately 15 microns).
than the more evenly dispersed striosomes.(ABSTRACT TRUNCATED AT 400 WORDS).
These parvalbumin-poor patches in the caudate nucleus and putamen aligned with the enkephalin-rich striosomes.
This resulted in clearly delineated islands of greatly reduced staining surrounded by a matrix of moderately reduced staining; the patches of greatly reduced staining corresponded with acetylcholinesterase-poor striosomes.
Ipsilateral SI and MI and contralateral MI all innervated matrisomes intermingled with striosomes and with matrisomes not receiving sensorimotor cortical input.
GluR1 immunoreactivity, but not GluR2/3 or GluR4 immunoreactivity, is more intense in the ventral striatum (i.e., nucleus accumbens) than in the dorsal striatum, and GluR1 is enriched within dendritic spines in the neuropil of the nucleus accumbens and striosomes in the dorsal striatum. Within striosomes, GluR1 immunoreactivity is more abundant than GluR2/3 immunoreactivity; GluR4 immunoreactivity is sparse in striosomes, but the matrix contains large, GluR4-positive cholinergic neurons. This study demonstrates that, within monkey striatum, subunits of ionotropic AMPA GluR have differential distributions within striosomes and matrix. Furthermore, the results suggest that neurons within striatal striosomes and matrix may express different combinations of GluR subunits, thus forming receptors with different channel properties and having consequences that may be relevant physiologically and pathophysiologically.
The well-known histochemical organization of the cat's striatum, characterized by the presence of small areas with poor concentration of AChE, called "striosomal bodies" or "striosomes", which were embedded in a prominent tissular matrix presenting more intense staining for AChE, was clearly recognized.
MEnk-positive striosomes were readily visualized in both the caudate nucleus and the putamen of the PDC cases.
NGF binding sites were distributed heterogeneously in the striatum with patches of low density, corresponding to AChE-poor striosomes, surrounded by a matrix in which receptor density was significantly greater.
All of the corticostriatal fiber projections observed primarily avoided immunohistochemically identified striosomes.
Terminal fields were located in striosomes, the dorsolateral rim of the neostriatum, the anterodorsal aspect of the nucleus accumbens shell, the infralimbic cortex, and the medial prefrontal cortex.
Combination of the low dose of SKF-38393 and quinpirole produced a synergistic effect on rotation and elicited, in the dopamine-depleted caudoputamen, a striking pattern of Fos-like protein expression in which Fos-positive neurons were concentrated in striosomes and in the dorsolateral caudoputamen.
In contrast, angiotensin-converting enzyme occurs in the substantia nigra pars reticulata and is enriched in the striosomes of the striatum.
Division of the mammalian neostriatum into two intermingled compartments called striosomes and matrix has been established by analysis of enzyme activity, neuropeptide distribution, nucleic acid hybridization, and neurotransmitter receptor binding. striosomes and matrix are distinct with respect to afferent and efferent connections, and these regions provide the potential for modulation and integration of information flow within basal ganglia circuitry. We examined binding to the three pharmacologically distinct ionotropic excitatory amino acid receptors, N-methyl-D-aspartate, alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid, and kainate, in human striatum using in vitro receptor autoradiography and compared the binding to striosomes and matrix histochemically defined by acetylcholinesterase activity. Our findings reveal increased binding to N-methyl-D-aspartate receptors and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptors in matrix relative to striosomes and increased kainate receptor binding in striosomes relative to matrix.
In the normal rats, 5'-nucleotidase activity was differentially concentrated in striosomes, where it produced a dense staining of the neuropil. Moreover, 5'-nucleotidase is prominently associated with glial membranes in the central nervous system, so that the concentration of this enzyme in striosomes could mark these as sites of selective glial populations within striatum. These properties and actions of 5'-nucleotidase in purinergic neurotransmission and in neuroadhesion may contribute to the specialized functions of striosomes and matrix..
At midgestation, patches of high density of cholecystokinin receptors are in register with the dopamine D1 receptor-enriched striosomes.
At every dose of amphetamine eliciting a response, the increased NGFI-A mRNA expression was preferentially concentrated in striosomes of the rostral caudoputamen, whereas cocaine at each dose given induced expression of NGFI-A mRNA in both striosomes and matrix at these striatal levels.
In the neostriatum sulfide-silver, staining was intense in the matrix, although the striosomes did not show appreciable reactivity.
The localization of calbindin was documented in a series of developing rat brains, as was the compartmental location of these cells relative to tyrosine hydroxylase (TH)-immunostained dopamine islands, sites of future striosomes. Surprisingly, calbindin expression in the matrix, although eventually distributed in strictly complementary fashion to striosomes, does not originate as a system complementary to dopamine islands. The prolonged disparity between the borders of dopamine islands and calbindin-poor zones, and the different spatiotemporal schedules of development of the islands and the calbindin gaps suggest instead that the final match between the borders of striosomes and surrounding matrix results from dynamic processes occurring early in postnatal development.
NADPH-d reactive patches corresponded to and showed a similar shift in the intensity of staining during development as acetylcholinesterase (AChE) reactive striosomes..
In the light of primate tracing studies these findings suggest that the ventral tier of the pars compacta projects to striosomes of the striatum and the dorsal tier, gamma group and retrorubral nucleus to the matrix compartment.
Moreover, within the regions of diminished uptake-site binding in the MPTP-treated monkeys, there is differential preservation of binding in striosomes relative to the surrounding matrix.
SP expression in the striatum had the characteristic patchwork of striosomes. This study represents the first unequivocal immunohistochemical demonstration of SP-positive striosomes in the human striatum..
We now show that this effect occurred in two striatal compartments, the striosomes and the extrastriosomal matrix, and was accompanied by increased immunostaining for the corresponding protein with a monospecific antibody.
Analysis of their topography and of the morphometric data indicates that they probably do not represent preserved striosomes.
The asymmetry in the crossed projection was again restricted to the rostral substantia nigra; interestingly, however, it was limited to the subset of neurons reported to terminate in the striosomes ("ventral cell type"). Moreover, the finding of a differential influence of hemivibrissotomy on nigrostriatal afferents to striosomes and matrix is indicative of a functional dissociation of these two systems..
The immunoreactive fibers within the striatum were mostly thin and varicose and formed patches corresponding to the striosomes, as visualized on adjacent sections immunostained for calbindin. Although some somatostatin cell bodies rimmed the striosomes, most of the positive cells were rather uniformly scattered in the striatum.
In addition, the distribution of cells expressing D2 receptor mRNA in the extrastriosomal matrix was compared to that in striosomes identified by the presence of a high density of 3H-naloxone binding sites. Labelled cells were mainly found in the matrix (3H-naloxone binding-poor) but were also seen in striosomes (3H-naloxone binding-rich).
4) All projections from SI avoid striosomes and innervate discrete zones within the matrix.
The compartmental organization of the thalamostriatal connection in the cat was studied by labelling thalamic fibers in anterograde axonal transport experiments and comparing their striatal distributions with the arrangement of striosomes and matrix tissue identified by histochemical staining methods. Nuclei of the medial division, which includes parts of the thalamic midline, projected primarily to striosomes. Medial division: Thalamic deposits involving the paraventricular and rhomboid nuclei of the thalamic midline elicited labelling of striosomes and, invariably, ventral extrastriosomal matrix, the nucleus accumbens, and the amygdala. Deposits involving the anterior intralaminar nuclei and the striatally projecting cells located lateral to the stria medullaris (anterior intralaminar complex) produced an even, diffuse labelling of the matrix tissue and weak labelling of the striosomes.
The modulation of DA release by cortical glutamate and/or aspartate-containing inputs through NMDA receptors in the matrix appears thus to be partly distinct from that observed in the striosomes, providing some functional basis for the histochemical striatal heterogeneity..
It is postulated that the cellular aggregates may represent the fundamental level of striatal organization and may be local modules for intrinsic information processing, modifying extrinsic data processed through the biochemical compartmentalization of the striatum imparted by striosomes, neuropeptides, and dopaminergic, thalamic and cortical afferents..
It is well known that the striatum has a chemical architecture dividing it into striosomes and matrix, and that these compartments have different input-output connections. Comparisons with adjoining sections stained to demonstrate striosomes established that the local groups of striatal output neurons sometimes abutted striosomes but often did not.
A variegated pattern of binding was seen in caudate nucleus and putamen and some correspondence of patches of low binding with striosomes was observed in the caudate.
The localization of D1 receptor patches corresponded to striosomes identified by TH-immunoreactive islands. Densitometric measurements showed that there was a parallel increase of D1 binding sites in both striosomes and the surrounding matrix from P0 to P4. The disappearance of D1 receptor patches observed in the dorsal striatum at P9 was due to a faster increase of D1 binding sites in the matrix than in striosomes between P4 and P9 whereas a significant difference was still observed between these two compartments in the ventral striatum of P9 rats.
This mesostriatal projection is compartmentally organized with distinct sets of DAergic neurons projecting to striosomes and extrasriosomal matrix, respectively, suggesting specialized channels directed at DAergic modulation of sensorimotor processing in the striatal matrix and limbic related mechanisms represented in the striosomal system.
During brain development, transient partitions of glia and glycoconjugates (glycoproteins, glycolipids, and glycosaminoglycans) surround forming functional units (e.g., nuclear divisions, whisker-related barrels, and neostriatal striosomes).
Within this nucleus caudatus the striosomes appeared connected with a subventricular zone of low acetylcholinesterase-activity.
Based on our experiments and on the literature we suggest that the histochemical compartmentalization of the SNc could be related, at least in part, to the subdivision of the striatum into AChE-poor striosomes and an AChE-rich extrastriosomal matrix..
In all areas of the caudate nucleus, the pattern of limbic system-associated membrane protein immunoreactivity was highly heterogeneous, labeling zones that were in register with areas expressing neurochemical markers that classically identify striosomes. The results show that the limbic system-associated membrane protein is expressed by neurons within the target areas (striosomes) of subsets of limbic afferents (originating mainly from the basolateral nucleus of the amygdala and the prefrontal cortex), whereas regions of the caudate nucleus (extrastriosomal matrix) receiving inputs from other subdivisions of the limbic system, such as the cingulate cortex and the ventral tegmental area, contain relatively low levels of limbic system-associated membrane protein immunoreactivity.
The patches in the caudate nucleus correspond closely with the acetylcholinesterase-poor striosomes.
Cortical areas in this field were found to have a highly organized projection to the striatum, selectively innervating striosomes dorsally and predominantly avoiding them ventrally within their striatal fields of termination. Therefore, the sources of input to striosomes and matrix are not categorical but switch according to the striatal region considered.
Regional differences in radioactivity could be determined with high resolution by quantitative autoradiography, at the level of cell layers within the hippocampus and cerebral cortex, and between striosomes of the caudate nucleus.
These pockets were identified as striosomes by calbindin28k and met-enkephalin immunohistochemistry carried out on adjacent sections. In the substantia nigra pars compacta, ventrally situated TH-positive neurons were especially affected, suggesting preferential depletion of TH-positive neurons projecting to striosomes.
In the caudate nucleus, these patches of high binding corresponded to striosomes since they register with acetylcholinesterase-poor zones. Possible substrates for converting enzyme include not only angiotensin I but also substance P and enkephalins, which are also concentrated in striosomes..
Stimulation of the caudate nucleus zones with cells responding to sensory stimuli induced cat's movement and corresponding lesions were situated around striosomes among large cells with long axons. Stimulation of "silent" zones (where we failed to record any neuronal activity) did not modify cat's behaviour, corresponding lesions were found inside striosomes in clusters of small and medium-size cells.
The striatum is anatomically organized into both distinctly bounded compartments (striosomes) and gradients of neuronal markers.
Within different sectors of striatum the neurones and their afferent and efferent connections are defined to striosomes and matrix representing a finer grain of intrastriatal organization, the functional significance of which is unclear.
In AD patients strong MEnk-like immunoreactivity was persistent in the striatum showing so-called "striosomes". MEnk-positive striosomes were also visible in the striatum of PSP patients and were similar to those of normal controls and of AD patients.
In rat striatal slices, the autoradiographic analysis of [ 3H]naloxone binding allows one to define highly labelled patches corresponding to the striosomes and representing about 17% of the total striatal volume, surrounded by a poorly labelled zone, the matrix.
In addition, the SND patients showed an inhomogeneous distribution pattern of residual CaN staining in the putamen, where remaining CaN immunoreactivity appeared as a characteristic patchwork of "islands" resembling the "striosomes" observed by the tyrosine hydroxylase or Met-enkephalin immunostaining in the putamen from normal individuals.
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