In contrast, in the remaining region, here named the pan-ventronasal domain, SPIG1-positive cells form a regular mosaic and project exclusively to the Medial terminal nucleus (MTN) of the AOS that mediates the optokinetic nystagmus as early as P1. 
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).
After a monocular injection of the cholera toxin B subunit (CTB) into the vitreous chamber of the eye, retinal projections to the Medial terminal nucleus (MTN) of the Accessory Optic System (AOS) were studied in the Japanese monkey.
The receptive field properties of neurons in the Medial terminal nucleus of the Accessory Optic System (MTN) that project to the ipsilateral nucleus of the optic tract (NOT) and dorsal terminal nucleus (DTN), as identified by antidromic electrical activation, were analysed in the anaesthetized rat.
Ninety minutes after acute nicotine (0.35 mg/kg, s.c.) the number of c-Fos-like immunoreactive nuclei was consistently increased in visuo-motor structures such as the superior colliculus, the Medial terminal nucleus of accessory optic tract, and the nucleus of the optic tract.
In contrast, injections involving fibers of passage in the optic tract, or centered in the Medial terminal nucleus of the Accessory Optic System, label cells distributed across the entire retinal surface.
Both immunolabeled somata and fibers were found in the dorsal and lateral terminal nuclei as well as in the interstitial nucleus of the superior fasciculus (posterior fibers); whereas only immunoreactive fibers were found in the ventral division of the Medial terminal nucleus, particularly its rostral portion.
Interestingly, cingulate and piriform cortex, superior colliculus and Medial terminal nucleus of the accessory optic tract were specifically activated by nicotine but not saline.
Subsequent nuclei labeled with PRV after infection of the flocculus/paraflocculus, or nodulus/uvula, included the following: vestibular (e.g., z) and inferior olivary nuclei (e.g., dorsal cap), accessory oculomotor (e.g., Darkschewitsch n.) and accessory optic related nuclei, (e.g., the nucleus of the optic tract, and the Medial terminal nucleus); noradrenergic, raphe, and reticular cell groups (e.g., locus coeruleus, dorsal raphe, raphe pontis, and the lateral reticular tract); other vestibulocerebellum sites, the periaqueductal gray, substantia nigra, hippocampus, thalamus and hypothalamus, amygdala, septal nuclei, and the frontal, cingulate, entorhinal, perirhinal, and insular cortices.
Intense MOR1-like immunoreactivity (LI) was seen in the 'patch' areas and subcallosal streak in the striatum, medial habenular nucleus, Medial terminal nucleus of the accessory optic tract, interpeduncular nucleus, median raphe nucleus, parabrachial nuclei, locus coeruleus, ambiguous nucleus, nucleus of the solitary tract, and laminae I and II of the medullary and spinal dorsal horns.
Furthermore, in one case with PGa injection, the Medial terminal nucleus, dorsal portion, was also labeled.
mu receptor-like immunoreactivity is widely distributed in the rat central nervous system with immunoreactive fibers and/or perikarya in such regions as the neocortex, the striatal patches and subcallosal streak, nucleus accumbens, lateral and medial septum, endopiriform nucleus, globus pallidus and ventral pallidum, amygdala, hippocampus, presubiculum, thalamic and hypothalamic nuclei, superior and inferior colliculi, central grey, substantia nigra, ventral tegmental area, interpeduncular nucleus, Medial terminal nucleus of the accessory optic tract, raphe nuclei, nucleus of the solitary tract, spinal trigeminal nucleus, dorsal motor nucleus of vagus, the spinal cord and dorsal root ganglia.
Morphologically, a GABAergic connection between the Medial terminal nucleus of the Accessory Optic System and the nucleus of the optic tract, two primary visual nuclei involved in the optokinetic reflex, has been demonstrated. In this study it was investigated if the Medial terminal nucleus forms an inhibitory input to movement direction selective units in the nucleus of the optic tract. Concomitantly, bipolar electrical stimulation was applied to the Medial terminal nucleus and its effect was studied on the visual responses of units in the nucleus of the optic tract. Units in the nucleus of the optic tract were strongly inhibited during electrical stimulation of the Medial terminal nucleus. However, although average spike rate levels of units in the nucleus of the optic tract increased with bicuculline, bicuculline did not reduce inhibition invoked by electrical stimulation of the Medial terminal nucleus.
Acute nicotine injections resulted in prominent Fos-like immunoreactivity (-LI) in the Medial terminal nucleus of the Accessory Optic System, the interpeduncular nucleus, and in the caudal linear subnucleus of VTA.
The Medial terminal nucleus is not present.
Delta binding (6-18 fmol/mg tissue) was high in the caudal portion of the substantia nigra pars reticulata, and in the Medial terminal nucleus of the Accessory Optic System (a region previously shown to contain DA dendrites).
Mu binding was relatively high in the central linear nucleus, and in the dorsal and medial divisions of the Medial terminal nucleus of the Accessory Optic System, which has been shown to contain DA dendrites.
Among those affected were the superficial stratum of the caudal superior colliculus (+25%), the optic tract bilaterally (+35 to 43%), the oculomotor cranial nerve nuclei (III, IV, VI; range of +21 to 47%), and the Medial terminal nucleus of the accessory optic tract which harbors dense fields of endothelin binding sites (bilateral increase of +70 to 96%).
c-fos expression was substantially attenuated in the superficial gray layer of superior colliculus, Medial terminal nucleus of the accessory optic tract, and the interpeduncular nucleus by pretreatment with the centrally acting nicotine antagonist mecamylamine, 5 mg/kg IP, but not with the peripherally acting antagonist hexamethonium, 4 mg/kg IP.
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.
In this report, we focus our attention on the Medial terminal nucleus (MTN).
Monocular enucleation, as studied on the mu opioid receptor population with this experimental approach, results in virtually a complete loss of mu opioid receptors throughout all four of the contralaterally located AOS nuclei, including both dorsal and ventral subdivisions of the Medial terminal nucleus (MTNd,v).
In this context, diffuse, non-fibrillar receptor immunoreactivity occurred in the lateral habenular nucleus and Medial terminal nucleus of the accessory optic tract.
The intrinsic morpho-functional organization of the Medial terminal nucleus of the Accessory Optic System was investigated in the guinea pig. Thus, while the retinal terminal field covered the entire Medial terminal nucleus, by far the largest density of labeled retinofugal axon terminals was found within its dorsal division.
Glucose utilization in MDMA-treated rats was reduced in the superior colliculus and Medial terminal nucleus of the Accessory Optic System, but was unchanged in the visual cortex and components of the auditory system.
Retinal projections, particularly the ipsilateral projections, to the Medial terminal nucleus (MTN) of the Accessory Optic System were investigated by autoradiography in adult rats after being reared in one of three different conditions: (1) normal visual experiences, (2) an application of trypan blue for intrauterine induction of congenital unilateral anophthalmia; and (3) the procedures for intrauterine production of congenital microphthalmia in which both eyes are reduced in size.
Interspersed among these, are a few larger, elongated neurons whose density becomes greater and whose shape becomes fusiform in correspondence to the zone of transition from the superior fasciculus to the ventral part of the Medial terminal nucleus (MTN).
To compare the spatial organization of the direction selectivity of neurons in the Medial terminal nucleus (MTN) of the Accessory Optic System with that of neurons in the adjacent ventral tegmentum, extracellular single-unit recordings were made in the anesthetized rabbit.
NGFRI staining was seen in a variety of sensory pathways and related structures, such as olfactory tract and glomerular layer of olfactory bulb; retina, optic nerve and tract, lateral geniculate nucleus, Medial terminal nucleus of the accessory optic tract, and olivary pretectal nucleus; ventral cochlear nucleus and to a lesser degree in dorsal cochlear nucleus, superior olive, and nucleus of lateral lemniscus; solitary tract; cuneate nucleus, gracile nucleus, and ventroposterior thalamic nucleus.
Single units within the Medial terminal nucleus of the Accessory Optic System were recorded and examined for their responses to a moving pattern, in both intact and decorticated urethane-anesthetized rats.
Cytoarchitectural analysis of nBOR with Golgi techniques has revealed a number of similarities between the anuran nBOR and the mammalian Medial terminal nucleus (MTN) with regard to cellular morphology, dendritic geometry, and retinofugal arborization patterns.
The rabbit accessory optic system exhibited two fasciculi (the inferior fasciculus, and the superior fasciculus consisting of the anterior fibers and the posterior fibers) and three terminal nuclei (the Medial terminal nucleus, and the anterior and posterior portions of the lateral terminal nucleus), but lacked the dorsal terminal nucleus. The Medial terminal nucleus and the posterior portion of the lateral terminal nucleus were commonly observed in the cat and dog. A small number of posterior fibers projected to the poorly-developed Medial terminal nucleus.
These cells were labelled after injection of either horseradish peroxidase or a fluorescent tracer, Fast Blue, into the Medial terminal nucleus (MTN) of the Accessory Optic System.
The existence of the retinal projection to the Medial terminal nucleus of the accessory nucleus was in doubt.
The metabolic activity of the Medial terminal nucleus (MTN) of the Accessory Optic System was studied by means of the [ 14C]2-deoxyglucose (2-DG) method in Long-Evans rats exposed to moving and stationary visual stimuli.
This nucleus is homologous to the dorsal division of the Medial terminal nucleus (MTN) in other mammals.
The most prominent accessory optic input was to the Medial terminal nucleus and was provided by the inferior fasciculus of the accessory optic tract.
The uncrossed optic projection to the Medial terminal nucleus of the Accessory Optic System was studied in adult rats with hereditary unilateral microphthalmia. Aberrant expansion of the uncrossed superior fasciculus fibers was observed in the Medial terminal nucleus..
Neuronal cell bodies in the Medial terminal nucleus of the Accessory Optic System (MTN) were labeled with WGA-HRP which was injected ipsilaterally into the occipital cortex in the rat.
One problem for the generalization of this theory is that the Medial terminal nucleus has never been found in primates.
Rabbit retinal ganglion cells were retrogradely labeled following injection of rhodamine-labeled microspheres into the Medial terminal nucleus. No double-labeled neurons were observed, i.e., ganglion cells projecting to the Medial terminal nucleus (MTN) had no axon collaterals to the superior colliculus.
In contrast to previous reports in primates, we find that both the ventral and dorsal divisions of the Medial terminal nucleus (MTN) receive projections from the retina.
The increase in the ipsilateral projection to the Medial terminal nucleus in animals receiving unilateral enucleation at birth was greater than after eye removal as an adult.
The retinal projection to the Medial terminal nucleus of the Accessory Optic System of the monkey was examined in several primate species which had received intraocular injections of [ 3H]proline or [ 3H]fucose.
The NRTP may also relay information related to vertical visuomotor reflexes (e.g., vertical optokinetic nystagmus) given the strong projections from the Medial terminal nucleus of the Accessory Optic System, visual tegmental relay zone, supra-oculomotor periaqueductal gray, interstitial n.
Retrogradely labeled cells were found in the Medial terminal nucleus (MTN) of the Accessory Optic System (AOS) when ventral portions of the uvula were involved in the injection site.
Projections of the Medial terminal nucleus (MTN) of the Accessory Optic System, the ventral tegmental area of Tsai, and the substantia nigra of the rabbit and the rat have been studied by the method of retrograde axonal transport of horseradish peroxidase.
The neurons of the Medial terminal nucleus (MTN) of the Accessory Optic System (AOS) have been studied in the rat, rabbit and cat in Golgi-Cox and Golgi-Kopsch impregnated brain sections.
The connections of the ventral tegmental area (VTA) and Medial terminal nucleus (MTN) of the Accessory Optic System were studied in the albino rat.
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. After the inferior fasciculus arrived at the ventromedial border of the cerebral peduncle, some fibers from the inferior fasciculus ran caudally to the Medial 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. However, all fibers of the inferior fasciculus ran caudally on the lateral surface of the hypothalamus or along the ventromedial border of the cerebral peduncle to terminate at the Medial terminal nucleus.
The projections of the Medial terminal nucleus (MTN) of the Accessory Optic System have been studied in the rabbit and rat following injection of 3H-leucine or 3H-leucine/3H-proline into the MTN and the charting of the course and terminal distribution of the MTN efferents.
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.
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..
EEG, EMG, and brain temperature were recorded under 24-hr (LD 12:12 or LD 10:14) and 1-hr (LD 0.5:0.5) cycles in rats which received either (1) no lesion, (2) primary optic tract lesions, (3) lesions of dorsal and lateral terminal nuclei of the Accessory Optic System, (4) lesions of Medial terminal nucleus of the Accessory Optic System, or (5) retinohypothalamic tract-suprachiasmatic nucleus lesions.
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.
The projections of the Medial terminal nucleus (MTN) of the Accessory Optic System (AOS) upon pretectal nuclei have been studied in pigmented rats by means of (i) the anterograde transport of 3H-leucine with the use of light autoradiography and (ii) the retrograde transport of horseradish peroxidase (HRP).
Fibers of the accessory optic tract (AOT) terminating in the Medial terminal nucleus (MTN) were observed in the mouse by the rapid Golgi method.
Recent evidence from extracellular recording studies indicates that the Medial terminal nucleus (MTN) of the rabbit accessory optic system receives inputs from a particular functional class of retinal ganglion cells--specifically, the on-type direction-selective cells.
The fibers of the inferior fasciculus (anterior accessory optic tract) run along the medial edge of the cerebral peduncle and terminate within the Medial terminal nucleus of the Accessory Optic System.
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