A high density of calcitonin gene-related peptide-immunoreactive perikarya was found in the superior colliculus, the dorsal nucleus of the raphe, the trochlear nucleus, the lateral division of the marginal nucleus of the brachium conjunctivum, the motor trigeminal nucleus, the facial nucleus, the pons reticular formation, the retrofacial nucleus, the rostral hypoglossal nucleus, and in the motor dorsal nucleus of the vagus, whereas a high density of fibers containing calcitonin gene-related peptide was observed in the lateral division of the marginal nucleus of the brachium conjunctivum, the parvocellular division of the alaminar spinal trigeminal nucleus, the external cuneate nucleus, the nucleus of the solitary tract, the laminar spinal trigeminal nucleus, and in the area postrema. 
Hydropic axonal swelling was also sparsely distributed in the pyramidal tract, pedunculus cerebellaris superior and brachium colliculi inferioris, but wallerian degeneration of these tracts was absent.
A discrete group of ChAT-IR cells is located in the sagulum, and additional cells are scattered in the nucleus of the brachium of the inferior colliculus.
At subcortical levels, we observed a similar correspondence of retrogradely labeled cells and anterogradely labeled axons and terminals in visual (posterior limitans thalamic nucleus) and multisensory thalamic nuclei (dorsal and medial division of the medial geniculate body, suprageniculate nucleus, posterior thalamic cell group, zona incerta), and in the multisensory nucleus of the brachium of the inferior colliculus.
This entry zone is bordered caudally by the intramesencephalic path of the trochlear, laterally by the spinothalamic tract, and rostrally by the caudal margin of the brachium of the superior colliculus.
We have used carbocyanine dye tracing from the brachium of the superior colliculus in conjunction with Nissl staining and immunohistochemistry to GAP-43 and calretinin to study the development of retinal projections to the superior colliculus in 17 human embryos and fetuses aged from 8 to 28 weeks. We also saw occasional retrogradely labelled somata following DiI insertion into the superior brachium.
toward the brachium of the inferior colliculus.
METHODS: Di-I, a fluorescein dye that allows anterograde labeling of axons, was injected into the brachium of the superior colliculus in post-mortem brain from a patient diagnosed with LHON (3460 mutation) and a normal control brain.
We have studied the postnatal development of the projection to the ferret SC from the nucleus of the brachium of the inferior colliculus (nBIC), its main source of auditory input, to determine whether the emergence of auditory map topography can be attributed to anatomical rewiring of this projection.
The subcortical terminal fields were observed in the pontine nucleus, the nucleus of the brachium inferior colliculus, and the intermediate and deep layers of the superior colliculus.
Electrical stimulation of the superficial visual layers (sSC) and of the auditory nucleus of the brachium of the inferior colliculus (nBIC) evoked robust monosynaptic responses in dSC cells.
A ventral subdivision, Pv, stains darkly when processed with the Cat-301 antibody and occupies the ventroanterior fifth of the pulvinar complex along the brachium of the superior colliculus. Unexpectedly, part of Pv is ventral to the brachium. Pc includes about half of the pulvinar complex, with parts on both sides of the brachium of the superior colliculus. The complex resembles the pulvinar of primates by having a portion ventral to the brachium and by having histochemically distinct nuclei; the number of nuclei is less than in primates, however..
Imaging disclosed a cystic mass in the left posterior thalamus with compression of the brachium of the left superior colliculus.
METHODS: DiI was embedded into the optic tract, brachium of superior colliculus and subplate of visual cortex in fixed postmortem human tissues of 7 fetuses.
Three tectofugal pathways, the tectothalamic, tectobulbar, and tectoisthmic tracts, exit the dorsal mesencephalon via the brachium of the superior colliculus, a large fiber structure, which can be divided in specific subtracts that are characterized by the selective expression of N-cadherin, cadherin-7, cadherin-6B, or R-cadherin.
Bilateral projections involved the (5) peripeduncular/suprapeduncular nucleus, (6) subparafascicular and posterior intralaminar nuclei, (7) nucleus of the brachium of the inferior colliculus, (8) lateral tegmental/lateral mesencephalic areas, and (9) deep layers of the superior colliculus.
Best results were obtained at 24 h postinjection, revealing a continuous pattern of anterograde labeling from the retina, optic nerve, and chiasm to the contralateral optic tract, the dorsal and ventral lateral geniculate nucleus, the superior colliculus and its brachium, the olivary pretectal nucleus, the nucleus of the optic tract, and the suprachiasmatic nucleus.
Based on this immunohistochemical staining, the border of PI is moved dorsally above the brachium of the superior colliculus and PI can be subdivided in five regions (PI(P), PI(M), PI(C), PI(L), and PI(LS)).
A caudal pathway projects medially to the posterior hypothalamic area and periaqueductal gray and caudally along the brachium of the superior colliculus to the medial pretectal area and the nucleus of the optic tract (IGL and VLG).
Here we report that tracer injections in the superficial layers label axons with en passant and terminal boutons, both in the deeper layers of the SC and in their primary source of auditory input, the nucleus of the brachium of the inferior colliculus (nBIC).
However, the rate of erroneous pathway choices was increased at the chiasm and the bifurcation between the ventral and dorsal brachium of the optic tract compared to unlesioned animals.
Correlation of functional deficits with NOT lesions from this and previous studies showed that rostral lesions of NOT in and around the pretectal olivary nucleus, which interrupted cortical input through the brachium of the superior colliculus (BSC), affected both smooth pursuit and OKN.
the habenulo-interpeduncular tract, decussation of the dorsal tegmentum, the medial longitudinal fasciculus, transverse pontine fibers, the brachium conjunctivum and the inferior cerebellar peduncle were cadherin-8 positive, as were the spinal tract of the trigeminal nerve, oculomotor nerve, facial nerve and trigeminal nerve.
After multiple injections of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) into the SC, the heaviest concentrations of labelled cells were found in the nucleus of the brachium (BIN) and external nucleus of the inferior colliculus, with much weaker labelling in the nucleus sagulum, dorsal, intermediate and ventral nuclei of the lateral lemniscus, paralemniscal regions, and periolivary nuclei.
Coding for auditory space in the nucleus of the brachium of the inferior colliculus in the ferret. The nucleus of the brachium of the inferior colliculus (BIN) projects topographically to the deeper layers of the superior colliculus (SC), which contain a two-dimensional map of auditory space.
However, a high density of immunoreactive fibers was found in the periaqueductal gray, the dorsal nucleus of the raphe, the locus coeruleus, and the marginal nucleus of the brachium conjunctivum.
Within the anterior midbrain, SHT axons traveled rostrally near the brachium of the inferior colliculus. These were in or near the mesencephalic reticular nucleus, brachium of the inferior colliculus, cuneiform nucleus, superior colliculus, central gray, and substantia nigra.
In auditory structures retrograde labeling was found mainly in the external nucleus of the inferior colliculus and in the nucleus of the brachium of the inferior colliculus.
Axons of all neurons coursed under NRTP and entered brachium pontis without having synapsed in the brain stem.
Less dense terminals were also seen in the nucleus of the brachium of the inferior colliculus, the cuneiform nucleus, the medial part of the paralemniscal tegmental field, and the dorsolateral division of the pontine nuclei on the ipsilateral side.
Conditioning-related changes of synaptic efficacy were measured in awake animals by examining mMG single-unit responses evoked by stimulation of one of two areas that send auditory CS and nonauditory information monosynaptically to the mMG, the brachium of the inferior colliculus (BlC) and the superior colliculus (SC).
Thus, following transection of the retinal fibers at the brachium of the superior colliculus (BSC) on postnatal-day 4 (P4) or later, no retinocollicular projections were observed in the adult stage.
We have deafferented the SC of adult hamsters at its brachium thus axotomizing the retinal ganglion cell axons rostral to its synaptic contact with the SC neurons. After unilateral brachium transection, a short segment of the autologous sciatic nerve was grafted to bridge the lesioned site to the SC (n = 28). As controls the brachium was transected and left ungrafted (n = 12). From these results we conclude that the brachium of the SC is conducive to axonal regeneration and the peripheral nerve graft is indeed effective in restoring distally axotomized visual pathway in adult mammals..
Fourteen SHT axons (40%) ended in the ipsilateral midbrain mainly in the superior colliculus, cuneiform nucleus or nucleus brachium inferior colliculus.
Further inputs to the LTR originated in the deep and intermediate layers of the ipsilateral superior colliculus and the ipsilateral periaqueductal gray, the contralateral LTR, and the contralateral marginal nucleus of the brachium conjunctivum.
Anterograde degeneration was also noted in nuclei and tracts related to the visual tectofugal system-the brachium of the superior colliculus, nucleus rotundus, pretectal nuclei, and the ectostriatum.
In the lateral tegmental field, the marginal nucleus of the brachium conjunctivum, the superior central nucleus, the nucleus sagulum, the dorsal nucleus of the raphe, the interpeduncular nucleus and the retrorubral nucleus the density of immunoreactive cell bodies was moderate. A high density of immunoreactive fibers was observed in the substantia nigra, the nucleus ruber, the superior and inferior colliculi, the periaqueductal gray, the interpeduncular nucleus, the central, magnocellular and lateral tegmental fields, the marginal nucleus of the brachium conjunctivum, the postpyramidal nucleus of the raphe, the inferior olive, the internal division of the lateral reticular nucleus and the medial and lateral nuclei of the superior olive.
The highest density of cell bodies was observed in the nucleus of the trapezoid body, whereas a low density of perikarya was found in the inferior and superior colliculi, nucleus of the brachium of the inferior colliculus and in the alaminar and laminar spinal trigeminal nuclei. A moderate density of immunoreactive fibers was found in the nucleus of the solitary tract, dorsal nucleus of the raphe, area postrema, dorsal motor nucleus of the vagus and in the marginal nucleus of the brachium conjunctivum, whereas a low density of fibers was observed in the lateral tegmental field, laminar and alaminar spinal trigeminal nuclei, nucleus of the trapezoid body, nucleus coeruleus, brachium conjunctivum, Kölliker-Fuse nucleus, periaqueductal gray and in the inferior and superior colliculi.
A moderate or low density of immunoreactive cell bodies was observed in the nucleus of the brachium of the inferior colliculus, pericentral nucleus of the inferior colliculus, ventral nucleus of the lateral lemniscus and in the external division of the lateral reticular nucleus. The densest network of immunoreactive fibres was visualized in the interpeduncular nucleus, marginal nucleus of the brachium conjunctivum, alaminar and laminar spinal trigeminal nuclei and in the substantia nigra. The periaqueductal gray, brachium of the inferior colliculus, nucleus of the brachium of the inferior colliculus, locus coeruleus, nucleus incertus, Kölliker-Fuse nucleus, facial nucleus, medial nucleus of the solitary tract and the area postrema contained a moderate density of immunoreactive fibres, whereas the pericentral nucleus of the inferior colliculus, nucleus sagulum, cuneiform nucleus, dorsal nucleus of the raphe, superior central nucleus, central, lateral and paralemniscal tegmental fields, ventral nucleus of the lateral lemniscus, dorsal tegmental nucleus, postpyramidal nucleus of the raphe, nucleus ambiguus, accessory dorsal tegmental nucleus, dorsal motor nucleus of the vagus and the inferior olive had the lowest density of immunoreactive fibres..
A high or moderate density of immunoreactive cell bodies was found in the superior central nucleus, nucleus incertus, dorsal tegmental nucleus, nucleus of the trapezoid body, and in the laminar spinal trigeminal nucleus, whereas a low density of such perikarya was observed in the inferior colliculus, nucleus praepositus hypoglossi, dorsal nucleus of the raphe, nucleus of the brachium of the inferior colliculus, and in the nucleus of the solitary tract. The highest density of immunoreactive fibers was found in the substantia nigra, dorsal motor nucleus of the vagus, nucleus coeruleus, lateral tegmental field, marginal nucleus of the brachium conjunctivum, and in the inferior and medial vestibular nuclei.
The highest density of immunoreactive fibers was observed in the substantia nigra, periaqueductal gray, marginal nucleus of the brachium conjunctivum, medial vestibular nucleus, medial nucleus of the solitary tract, laminar spinal trigeminal nucleus, inferior colliculus, medial division of the dorsal nucleus of the raphe, locus coeruleus, dorsal tegmental nucleus and in the spinal trigeminal tract.
Finally, a few immunoreactive fibers were observed in the pontine gray, nucleus coeruleus, marginal nucleus of the brachium conjunctivum, nucleus of the solitary tract, inferior olive, and in the tegmental fields..
Hamsters with transection of the brachium of SC (BSC) at the prectectal-SC (PT-SC) border were severely impaired in their ability to approach stationary targets in central and peripheral fields.
Magnetic resonance imaging revealed a lesion in the right dorsal midbrain extending from the brachium of the superior colliculus to the inferior colliculus.
These labeled structures included the central nucleus of the amygdala; the entopeduncular nucleus; the globus pallidus; the reticular and ventral lateral geniculate nuclei of the thalamus; parts of the hypothalamus including the dorsal, lateral, and posterior hypothalamic areas and the ventromedial and parvicellular nuclei; the zona incerta and fields of Forel; parts of the substantia nigra including the pars reticularis and pars lateralis, and the retrorubral area; the pretectum; the intermediate and deep layers of the superior colliculus; the periaqueductal gray; the dorsal nucleus of the raphe; portions of the reticular formation, including the mesencephalic, pontis oralis, pontis caudalis, gigantocellularis, ventralis, and lateralis reticular nuclei; the nucleus cuneiformis; the marginal nucleus of the brachium conjunctivum; the locus coeruleus; portions of the trigeminal complex, including the principal sensory and spinal nuclei; portions of the vestibular complex, including the lateral division of the superior nucleus and the medial nucleus; deep cerebellar nuclei, including the medial and lateral cerebellar nuclei; and lamina VII of the cervical spinal cord.
The TG arteries usually penetrated the medial geniculate body (100%), pulvinar thalami (80%), brachium of the superior colliculus (53.33%), or lateral geniculate body (13.33%). The collateral branches of the TG arteries were noted to reach the medial geniculate body (76.67%), pulvinar (70%), brachium of the superior colliculus (40%), crus cerebri (40%), and lateral geniculate body (6.67%).
Destruction of collicular neurons by excitotoxins dramatically reduced AChE staining in fibers of the brachium and superficial gray layer of the superior colliculus.
D-type cells were loosely clustered in the lateral part of the central tegmental field dorsal to the substantia nigra, extending dorsally in the medial division of the posterior complex of the thalamus and medial side of the brachium of the inferior colliculus.
Some crossed fibers ascended with the contralateral brachium conjunctivum and terminated in the midbrain tegmentum.
These somatosensory units were found to occupy many of the region's structures, notably the intercollicular nucleus (INC), the nucleus of the brachium of the inferior colliculus, the stratum griseum intermedium and the stratum griseum profundum of the superior colliculus.
HRP-labeled axons of the paralemniscal-facial pathway were observed to cross the midline by traveling ventral to the brachium conjunctivum in the caudal mesencephalon.(ABSTRACT TRUNCATED AT 400 WORDS).
Type I PPE neurons were observed in diverse brainstem structures including the mesencephalic and pontine central gray matter, various reticular and raphe nuclei, the ventral tegmental area of Tsai, the interpeduncular nucleus, the nucleus of the brachium of the inferior colliculus, the ventral and dorsal tegmental nuclei of Gudden, the sphenoid nucleus, the laterodorsal tegmental nucleus, Barrington's nucleus, the parabrachial region, the lateral lemniscus and its related nuclei, the trapezoid nucleus, the rostral and ventromedial periolivary nuclei, the mesencephalic trigeminal and principal sensory trigeminal nuclei, the locus coeruleus, the subcoeruleus nucleus, the medial and spinal vestibular nuclei, the dorsal and ventral cochlear nuclei, the medial and lateral cerebellar nuclei, the Roller nucleus, and the intermedius nucleus of the medulla.
Lesions of the fiber tract in the pulvinar that inputs to the brachium of the superior colliculus caused a transient reduction in the buildup and peak velocity of OKN and OKAN. A fiber tract in the pulvinar that inputs to the brachium of the superior colliculus appears to carry activity related to retinal slip from the visual cortex to NOT and DTN..
Intensely stained NADPH-diaphorase-positive nerve fibers were found in the stria terminalis, marginal region of the central tegmental field, dorsal tegmental nucleus, and spinal trigeminal tract as well as around the brachium conjunctivum.
Other afferents that terminate in the intermediate gray layer, such as the input from the nucleus of the brachium of the inferior colliculus (BIN), are almost completely segregated from the above inputs and show very little overlap with the NADPH-diaphorase lattice.
Finally, we found that the cells of the nPg undergo a hypertrophic response, similar to that seen in other neurons after axotomy, following retinal removal or section of the dorsomedial brachium of the optic tract.
In all experimental animals, axons were observed regenerating through the visual pathway but at the brachia most of the fibers were channeled through the ventral brachium. We present evidence that fibers in the ventral brachium originated from ganglion cells in all regions of retina and that these fibers grew almost exclusively into ventral half tectum even though some of these fibers would normally synapse in dorsal half tectum.
Transplant-derived astrocytes were found on the glia limitans along the entire circumference of the brain, in the hippocampal commissure, corpus callosum, internal capsule, entopeduncular nucleus, habenular commissure, brachium of the superior colliculus, optic tract, optic chiasm, and sensory root of the trigeminal nerve.
The labelled cells were distributed in a sparse band arching below the margin of the brachium of the superior colliculus between the dorsal and lateral borders of the brainstem at the caudal edge of the pulvinar.
This included portions of NOT that lie in and around the brachium of the superior colliculus and adjacent regions of the dorsal terminal nucleus (DTN).
By 34 PCD only the adult-like projection extending from the brachium to the periaqueductal gray (PAG) is apparent.
(2) Terminal labeling after injection of tracer into LCN was found mainly in Inc, SGI, and SGP, but sparse labeling was also observed in the nucleus of the brachium of the inferior colliculus (BIN), PAG, PBN, PTP, and D.
Fetal neural tissue was transplanted into suction lesions of the left brachium and pretectal region in young rats.
Cell bodies in the midbrain containing SS immunoreactivity were found in the superficial and intermediate gray layers of the superior colliculus, the interpeduncular nucleus, the raphe, the inferior colliculus and nucleus of its brachium, the nucleus of the optic tract, and the lateral tegmental field.
Essentially, six regions in the brainstem contained retrogradely labeled cells: the superior colliculus, the parabigeminal nucleus, the dorsal raphe nuclei, the parabrachial area of the central tegmental field, the marginal nucleus of the brachium conjunctivum, and the nucleus coeruleus. In the sections immunostained for ChAT, double-labeled cells were located in the central tegmental field, in the marginal nucleus of the brachium conjunctivum, and in the nucleus coeruleus. In the sections treated for TH and DBH, double-labeled cells showed a similar distribution, and like the ChAT(+) cells, they were located mainly in the central tegmental field, in the marginal nucleus of the brachium conjunctivum, and in the nucleus coeruleus. The majority of retrogradely labeled cells were located in the region of the central tegmental field in the vicinity of the brachium conjunctivum, and most of these cells were also ChAT-immunoreactive.
Terminal fields associated with the major bundle of fibres are found in an area medial to the brachium of the inferior colliculus; the parabigeminal nucleus and adjacent tegmentum; the ventrolateral midbrain reticular formation; and the lateral pontine nuclei.
Suction lesions of the brachium of the left superior colliculus (SC) and pretectal region were made in 6-11-day-old hooded rats.
It is concluded that: the substantia innominata, caudal periventricular and periaqueductal gray, lateral pontine and medullary reticular formation represent relay stations of vocalization-controlling pathways; the periaqueductal gray represents the lowest relay station above the level of motor coordination; neurons responsible for motor coordination of vocalization lie in the reticular formation around the caudal brachium conjunctivum, the superior olive, n.
Fibres growing onto the contralateral, or a 'virgin' tectum mostly grow straight onto the rostral margin of the tectal lobe, without growing around its margin in the form of a medial or lateral brachium. Fibres regenerating to an innervated ipsilateral tectum mostly enter either the medial or lateral brachium of the optic tract, and only leave this close to their site of termination.
Retrograde transport of horseradish peroxidase (HRP) after complete transection of the brachium of the superior colliculus on the day of birth in hamsters revealed preferential labelling of the temporal retina.
The main terminal area was situated at the level of transition between the superior and inferior colliculus on the side contralateral to the injection site and comprised the intercollicular nucleus and part of the external and pericentral nuclei of the inferior colliculus and of the nucleus of the brachium of the inferior colliculus, but there were also projections to the caudal half of the deep and intermediate gray layers of the superior colliculus, the anterior and posterior pretectal nuclei, the nucleus of Darkschewitsch and nucleus ruber.
Three kinds of axons travel predominantly in the brachium of the inferior colliculus and enter the medial geniculate body ventromedially: group I, thin axons resembling ivy tendrils ending along dendrites; group II, thicker axons with a sinuous course and few branches; group IV, coarse thick axons with grumous collaterals and massive peridendritic terminals near principal cells and interneurons. Three kinds of axons enter from the parabrachial region and pass laterally: group III, very thin axons with many collaterals forming dense terminal nests; group V, runcinate axons with sparse, thin collaterals; group VI, either medium-sized (group VIa) or thin (group VIb) smooth axons, perhaps corticofugal, and ending near principal neuron dendrites; group VII, thick axons, entering from the auditory radiation, with large, grapelike terminal arbors; and group VIII, thin and forming peridendritic festoons on principal cells after entering from the brachium of the superior colliculus.
The third and heaviest projection field (P3) is located posteromedially in the inferior pulvinar but also includes small portions of the lateral and medial pulvinar that lie dorsal to the brachium of the superior colliculus.
The status of the inferior colliculus of the cat as an obligatory relay in the ascending auditory pathway was examined by attempting to infiltrate totally the fibres of the brachium of the inferior colliculus on one side with horseradish peroxidase.
At the brachial bifurcation, roughly 20% of the regenerated fibers chose the incorrect brachium vs.
The main subdivisions of the auditory tegmentum are the pericollicular areas, the nucleus of the brachium of the inferior colliculus, and the sagulum.
Ascending projections from the nucleus of the brachium of the inferior colliculus (NBIC) in the cat were studied by the autoradiographic tracing method. Many fibers from the NBIC ascend ipsilaterally in the lateral tegmentum along the medial border of the brachium of the inferior colliculus.
More scattered DCN fibers are present in the cuneiform nucleus (CF), the lateral part of the periaqueductal gray (PAG1), the red nucleus (NR), the nucleus of the brachium of the inferior colliculus (B), the mesencephalic reticular formation (MRF) and the intermediate and deep layers of the superior colliculus (SI, SP).
brachium conjunctivum stimulation evokes two distinct responses in thalamic relay cells.
The presence of degenerating nigral and cerebellar synaptic terminals in the intermediate and deep layers of the cat superior colliculus was demonstrated by electron microscopy following lesions of the substantia nigra or brachium conjunctivum. Two kinds of cerebellar terminals were distinguished by general appearances such as size, type of synaptic contact and type of synaptic vesicle and by the pattern of degenerative changes following electrical lesion of the brachium conjunctivum. The finding of the two types of degenerating terminal after lesion of the brachium conjunctivum can be considered as evidence of the coexistence of at least two kinds of cerebellar terminals in the superior colliculus.
Auditory responses in the suprageniculate nucleus were poorly defined and many units did not respond to tonal stimuli; following HRP injections no filled cells were found in the inferior colliculus, but labeled cells were found in the deeper layers of the superior colliculus and in the interstitial nucleus of the brachium of the inferior colliculus.
Hence, axons from ganglion cells in the dorsotemporal retina are in the dorsal optic brachium rather than in the ventral optic brachium as was previously assumed..
Retinofugal fibers project to the medial part of PI, adjacent to the brachium of the superior colliculus.
The dorsal fasciculus originates from the brachium colliculi superioris and descends the posterior surface of the medial geniculate body and the posterolateral surface of the crus cerebri as an independent fasciculus to enter the medial terminal nucleus.
In hamster only two putatively auditory structures showed labeled cells, the external nucleus of inferior colliculus and nucleus of the brachium of the inferior colliculus, whereas in cat additional cells are reported in the dorsal cochlear nucleus, trapezoid and superior olivary nuclei, and nucleus of the lateral lemniscus.
Although the vast majority of cerebellopontine axons reached the BPN via the descending limb of the brachium conjunctivum (BC) after crossing the midline within the midbrain, a relatively small number of ipsilaterally projecting fibers was also observed.
Overlapping retrogradely filled cells and anterogradely transported terminal grains were found to be located only within a crescent shaped region which traverses the brachium of the superior colliculus to include the inferior pulvinar and dorsal overlying lateral pulvinar.
From the tectodiencephalic junction to the tectal termination of the fibres there are differences between the three situations investigated; fibres regenerating to a 'virgin' ipsilateral, or to a denervated contralateral tectum, tend to grow straight onto the tectum, instead of being channelled into lateral or medial brachium as uncut fibres tend to be.
Ventral retinal fibres approached the tectum via the medial brachium and dorsal retinal fibres passed through the lateral brachium, while temporal retinal fibres formed a narrow band in the centre of the tract and entered the tectum directly at its rostral border. Fibres from VV eyes all entered the tectum via the medial brachium and fibres from TT eyes formed a narrow tract and entered the tectum directly from its rostral extremity.
Mainly unilateral pathways reach the ventromedial nucleus of thalamus and also pass under the lateral part of the colliculus to reach the region of the nucleus pendunculo-pontinus among the fibres of the brachium conjunctivum.
Increase in 10-nm filaments within axons was noticeable from 10 days onwards in the superior colliculus and in the brachium of the superior colliculus.
After injections of horseradish peroxidase into the central tegmental field of the midbrain reticular formation and centrum medianum of the thalamus in the cat, labelled neurons were found in the nucleus of solitary tract, cuneate and gracile nuclei, spinal nuclei of trigeminal nerve, external nucleus and brachium nucleus of inferior colliculus, nuclei of the lemniscus lateralis in the area pretectalis, nucleus of the posterior commissure and stratum intermediale of the superior colliculus and in reticular structures of medulla and pons.
They disappeared first from the fibres in the brachium of the superior colliculus, perhaps by transport towards the terminals, and later from the axons within the superior colliculus itself.
A caudal field is located within the sub-brachial nucleus of the optic tract, located between the brachium of the superior colliculus and the posterior pretectal nucleus.
Cortical fibres reaching the contralateral SC pass through the brachium of the ipsilateral SC.
In addition of these projections, the parabrachial region and interstitial nucleus of the brachium of IC (BIC) are identified as common targets of projections of each nucleus of IC on the ipsilateral side.
In addition to a sham injection, control injections were also made to the medial lemnisuc, red nucleus, deep tegmental decussations, mesencephalic reticular formation and brachium conjunctivum.
The brachium of the superior colliculus contained swollen axons and the cortex was diffusely involved with spheroids.
In addition, the rostral field projects to a small area of the medial pulvinar just anterior to the brachium of the superior colliculus..
A fair number of degenerated second order auditory fibers ascended in the contralateral brachium of the inferior colliculus and were distributed both to the principle and magnocellular divisions of the medial geniculate body.
There is no anterior accessory optic tract but a posterior tract containing only crossed fibres leaves the brachium of the superior colliculus and ends in the two nuclei, the medial and lateral terminal nuclei, lying either side of the cerebral peduncle.
The animals' localization accuracy was determined before and after one of the following operations: 1) transection of the trapezoid body, 2) unilateral and 3) bilateral transection of the lateral lemniscus, 4) unilateral and 5) bilateral transection of the brachium of the inferior colliculus. The results after bilateral transections of the lateral lemniscus and the one deep bilateral transection of the brachium of the inferior colliculus indicate that some portion of the ascending auditory system must be intact above the medulla for an animal to be able to localize sound. A small loss in accuracy of localization was found after unilateral transection of the lateral lemniscus or brachium of the inferior colliculus.
In those cases in which the nucleus rotundus deficit was observed, the lesions were found to include the nucleus subpretectalis, which, like nucleus rotundus, receives tectofugal fibers via the brachium of the superior colliculus.
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