Outside of the telencephalon at P9, we found distinct label in nucleus ovoidalis (OV), Nucleus spiriformis lateralis (SpL), and nucleus subpretectalis (SP) in the midbrain, almost the entire diencephalon including nucleus dorsomedialis posterior thalami (DMP), stratum griseum et fibrosum superficiale (SGF) in optic tectum, and Purkinje cells in cerebellum. 
Four pretectal nuclei of the chick brain, namely, the nucleus pretectalis, the Nucleus spiriformis lateralis, the nucleus spiriformis medialis, and the nucleus lentiformis mesencephali, were included in the study, and they all showed AMPA-positive neurons.
The time-course of development of different nAChR subunits revealed several instances of transient expression (such as in the cerebellum), increasing expression (such as in the Nucleus spiriformis lateralis), and diminishing expression into posthatching stages (such as in the oculomotor and throclear nuclei).
The possible participation of basal ganglia and associated structures [ dorsal striato-pallidum, Nucleus spiriformis lateralis (SpL), ectostriatum] in the elaboration of the optocollic reflex (OCR) was investigated by making bilateral chemical lesions (ibotenic acid).
Labeled fibers and terminals were also observed in the avian subthalamic nucleus (anterior nucleus of the ansa lenticularis), in the pretectum (Nucleus spiriformis lateralis) and in the avian substantia nigra pars reticulata.
In addition to this pathway, birds possess a major descending pathway from the basal ganglia to the tectum via the GABAergic Nucleus spiriformis lateralis in the pretectum.
The paleostriatal complex is the source of the ansa lenticularis with projections to the Nucleus spiriformis lateralis and the nucleus tegmenti pedunculopontinus, both projecting to the deep tectum.
These structures included, for example, the interpeduncular nucleus, Nucleus spiriformis lateralis, optic tectum, pretectal visual nuclei, and the lateral hypothalamus.
The Nucleus spiriformis lateralis had the highest levels of 3H-nicotine binding in the chicken brain, but it did not bind either of the two snake neurotoxins.
High numbers of beta 2-LI somata were found only in the Nucleus spiriformis lateralis, whereas neuropil staining for beta 2-LI was intense in the nucleus geniculatus lateralis ventralis, nucleus suprachiasmaticus, nucleus lateralis anterior, nucleus habenularis lateralis, area pretectalis, griseum tecti, nucleus lentiformis mesencephalis, nucleus externus, and nucleus interpeduncularis, and in the stratum griseum centrale, stratum griseum et fibrosum superficiale, and stratum opticum of the tectum.
Based on cytoarchitectural and HRP results, the pretectum of the adult hen was divided into the following eight nuclei: nucleus principalis pretectalis (P), nucleus subpretectalis (SP), nucleus principalis precommissuralis (PPC), nucleus medialis pretectalis (PTM), nucleus pretectalis dorsalis (APd), nucleus area pretectalis (AP), Nucleus spiriformis lateralis (SPL), and nucleus spiriformis medialis (SPM).
The Nucleus spiriformis lateralis also contained cholinergic fibers, while most of the cell bodies in the nucleus spiriformis medialis were cholinergic.
Both labelled Nucleus spiriformis lateralis and nucleus geniculatus lateralis, pars ventralis especially heavily and also labelled the nucleus habenula medialis; nucleus subpretectalis; nucleus isthmi, pars magnocellularis; nucleus reticularis gigantocellularis; nucleus reticularis lateralis; nucleus tractus solitarii; nucleus vestibularis dorsolateralis; nucleus vestibularis lateralis; nucleus descendens nervi trigemini; and the deep cerebellar nuclei.
As is true of neurons of the Nucleus spiriformis lateralis of the avian pretectum, the neurons of the homologous cell group in turtles, the dorsal nucleus of the posterior commissure of the pretectum, were found to contain enkephalin and have an enkephalinergic projection to the deep layers of the ipsilateral tectum.
Thus some features of the NT binding observed here in pigeon brain including the existence of substantial NT binding sites in the brainstem catecholamine nuclei, pretectum (Nucleus spiriformis lateralis), and optic tectum may reflect the existence, at least in part, of functional receptors for LANT6.(ABSTRACT TRUNCATED AT 400 WORDS).
Immunoreactive cell bodies were found in the telencephalon, diencephalon, and mesencephalon in areas as yet uncharacterized as discrete nuclei in birds (E-1, E-2, E-3, E-4, E-5); further cells were located in the diencephalic Nucleus spiriformis lateralis, the midbrain medial intercollicular nucleus (E-6), the nucleus mesencephalicus lateralis, pars dorsalis, the Edinger-Westphal nucleus and dorsal occulomotor nucleus; and in the nucleus of cranial nerve X and an uncharacterized area in the dorsolateral medulla (E-7).
Kainic acid had a local necrotizing effect; for example, it destroys neurons in the PC, nucleus rotundus, Nucleus spiriformis lateralis, nucleus ruber and neurons of the cerebellar cortex.
After injection into the palaeostriatum, labeling can be observed (i) in the neostriatum dorsale, (ii) in the hyperstriatum ventrale, (iii) in the archistriatum, (iv) in the diencephalic nuclei, nucleus ansae lenticularis and Nucleus spiriformis lateralis, and (v) in the mesencephalic nuclei, nucleus tegmenti pedunculo-pontinus and nucleus intercollicularis.
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