In the accessory optic system, the lateral terminal nucleus contained both NPY and VIP neurones, while in the dorsal terminal nucleus only NPY neurones were found. 
Within the rodent visual system, calcitonin gene-related peptide (CGRP) is selectively expressed in neurons in the accessory optic nuclei (AON), including the dorsal terminal nucleus (DTN), lateral terminal nucleus (LTN) and medial terminal nucleus (MTN).
Retinal connections to the DTN and MTN of the AOS were clearly discerned but no lateral terminal nucleus with retinal afferents was found.
The connections of the lateral terminal nucleus (LTN) of the accessory optic system (AOS) of the marmoset monkey were studied with anterograde 3H-amino acid light autoradiography and horseradish peroxidase retrograde labeling techniques.
These nuclei include the dorsal (MTNd) and ventral (MTNv) divisions of the medial terminal nucleus, the lateral terminal nucleus, the interstitial nucleus of the superior fasciculus, the posterior fibers, and the visual tegmental relay zone. These neurons are of the highest density in the lateral terminal nucleus (204 neurons/mm2). These are of extremely high concentration in the visual tegmental relay zone (316 neurons/mm2) and are also of substantial densities in the MTNd (77 neurons/mm2), lateral terminal nucleus (72 neurons/mm2), and MTNv (44 neurons/mm2).
Injections in STS separately involved the areas MT and MST, and resulted in labels within the lateral terminal nucleus of the AOS.
The suprachiasmatic nucleus and the lateral terminal nucleus of the accessory optic tract receive extremely weak, through bilateral retinal input.
This high velocity deficit in upward VOKN is consistent with the results of single unit studies of the lateral terminal nucleus (LTN) of the accessory optic system which suggest that visual cortical input (via the LTN) makes a direction specific contribution to the motion sensitivity of VOKN..
Statistically significant increases were also observed in the lateral geniculate nucleus, the lateral terminal nucleus and the cerebellum.
In order to reach their terminal field, these labeled fibers appeared to leave the accessory optic tract in the vicinity of the dorsal border of the lateral terminal nucleus and run medially through the substantia nigra..
Also, terminals sparsely covered the entire neuropil of the contralateral lateral terminal nucleus in some but not all wild-type mice.
DYN B cell bodies were present in nonpyramidal cells of neo- and allocortices, medium-sized cells of the caudate-putamen, nucleus accumbens, lateral part of the central nucleus of the amygdala, bed nucleus of the stria terminalis, preoptic area, and in sectors of nearly every hypothalamic nucleus and area, medial pretectal area, and nucleus of the optic tract, periaqueductal gray, raphe nuclei, cuneiform nucleus, sagulum, retrorubral nucleus, peripeduncular nucleus, lateral terminal nucleus, pedunculopontine nucleus, mesencephalic trigeminal nucleus, parabigeminal nucleus, dorsal nucleus of the lateral lemniscus, lateral superior olivary nucleus, superior paraolivary nucleus, medial superior olivary nucleus, ventral nucleus of the trapezoid body, lateral dorsal tegmental nucleus, accessory trigeminal nucleus, solitary nucleus, nucleus ambiguus, paratrigeminal nucleus, area postrema, lateral reticular nucleus, and ventrolateral region of the reticular formation.
The large lateral terminal nucleus (LTN) receives a dense projection from the retina and forms a prominent bulge on the lateral surface of the cerebral peduncle.
Within the all terminal nuclei of the accessory optic tract the retinal fibers were found to terminate bilaterally with contralateral preponderance, mostly in the MTN, while ipsilateral fibers terminate most extensively in the lateral terminal nucleus of the accessory optic tract (LTN).
The rat accessory optic system consisted of the inferior fasciculus, the superior fasciculus, the medial terminal nucleus, the lateral terminal nucleus, and the dorsal terminal nucleus. The golden hamster accessory optic system also consisted of the inferior fasciculus, the superior fasciculus, the medial terminal nucleus, the lateral terminal nucleus, and the dorsal terminal nucleus. The guinea pig accessory optic system and rat accessory optic system were similar, but the posterior fibers of the superior fasciculus decreased in number, and the dorsal terminal nucleus and the posterior portion of the lateral terminal nucleus were not observed in the guinea pig accessory optic system..
Unilateral lesion of the lateral terminal nucleus of the AOS (LTN) and the resulting retinal deafferentation of the medial terminal nucleus of the AOS (MTN) induced a spontaneous nystagmus in the dark whose slow phase was directed ipsilaterally to the lesion.
An efferent projection has been found to superior colliculus, pretectal region, dorsal lateral geniculate nucleus, contralateral vLGN, zona incerta, pontine nuclei, suprachiasmatic nucleus, lateral terminal nucleus of the accessory optic system and intralaminar nucleus of thalamus.
The results indicate that except for a moderate number of fibers entering the dorsal terminal nucleus and the lateral terminal nucleus respectively, all optic fibers constituting the dorsal and lateral fasciculi descend the lateral surface of the brain to terminate in the medial terminal nucleus. No ascending optic nerve fiber to the dorsal or lateral terminal nucleus is included in these fasciculi..
In addition to known optic pathways, we observed labeled fibers which left the lateral terminal nucleus of the accessory optic system, traveled around the cerebral peduncle, and could be followed as far as the medial terminal nucleus..
The lateral fasciculus branches from the main optic tract at the level of the ventral nucleus of the lateral geniculate body and descends the lateral surface of the crus cerebri to enter the medial terminal nucleus after contributing a few fibers to the lateral terminal nucleus.
Selective projections from area PLLS to the lateral terminal nucleus and from areas 17 and 18 to the medial terminal nucleus were noted.
The retinal projection is virtually completely crossed to the medial terminal nucleus and to the lateral terminal nucleus.
This system extends to the substantia nigra, lateral terminal nucleus of the accessory optic tract, central grey in the midbrain, and to the parabrachial nuclei, nucleus of the mesencephalic trigeminal tract, nucleus of the solitary tract in the hindbrain..
Possible visual functions of zona incerta (ZI) and lateral terminal nucleus of the accessory optic tract (LTN) in rats were investigated by comparing the effects of localized lesions on a series of discrimination learning tasks.
The three ventromedial projections involved: (1) a geniculopontine tract which coursed through the basis pedunculi and the lateral lemniscus to terminate in the dorsomedial and dorsolateral parts of the pons after giving terminals to the lateral terminal nucleus of the accessory optic tract, (2) a projection via Meynert's commissure to the suprachiasmatic nuclei of both sides of the brain stem as well as to the contralateral ventral lateral geniculate nucleus and lateral terminal nucleus of the accessory optic tract, and (3) a medial projection to the ipsilateral zona incerta.
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