Habenular Commissure

Pineal gland was located in the Habenular Commissure in the most caudal portion of the third ventricular roof, lying in a dorso-caudal position from the base to the apex.  

These axons, together with axons from migrated neurons of the posterior tuberculum and pallial neurons, cross the midline via the Habenular Commissure. These include an unusual type of forebrain projection: axons that cross the midline twice, at both the anterior and Habenular Commissures.  

They run from the Habenular Commissure into the connective tissue septa and further into the pineal parenchyma.  

brama has no deep pineal in the posterior region (near the Habenular Commissure).  

In addition, we found that DCC is expressed in the Habenular Commissure, the fasciculus retroflexus, and the stria medularis.  

Additional neurons within the murine diencephalon also expressed calretinin positive cell bodies and, or neuronal processes, including the stria medullaris, the Habenular Commissure and the paraventricular thalamic nucleus.  

laevis brain, besides those in the rostralmost dorsomedial and ventromedial telencephalon and septopreoptic area, mGnRH neurons were also found in the habenulae and Habenular Commissure as well the infundibular hypothalamus.  

Corpora arenacea occur not only in the actual pineal tissue but also in the leptomeninges, in the Habenular Commissure and in the choroid plexus.  

The olfactory projection consists of three tracts: the lateral olfactory tract, which projects bilaterally to the lateral cortex and the rostral amygdala, crossing the midline through the stria medullaris-Habenular Commissure system; the intermediate olfactory tract, which projects ipsilaterally to the olfactory tubercle and contributes to the contralateral projection; and the medial olfactory tract, which projects ipsilaterally to the dorsomedial retrobulbar formation.  

A small number of projections, which join the stria medullaris, protrude into the diencephalon, decussate in the Habenular Commissure, and turn rostrally back into the telencephalon to synapse in the caudal part of the contralateral terminal field.  

These data reveal that septal projections to the MHb, which are normally ipsilateral, respond to a unilateral deafferentation by extending contralateral fibers that cross the midline at the Habenular Commissure and reinnervate the caudal regions of the nucleus..  

The conspicuous Habenular Commissure contains interhemispheric fibers that appear to form occasional contacts within the habenulae.  

It was unaffected by transection of Habenular Commissure.  

The pineal tract fibres innervate the Habenular Commissure, habenular nucleus, subcommissural organ, posterior commissure and pretectum, and are AChE-positive.  

A few immunoreactive fibers were also observed in the Habenular Commissure.  

In the cat, we found GABA-immunoreactive interneurons, while the secondary nerve cells, whose axons enter the Habenular Commissure, were GABA-immunonegative.  

In addition, NAALADase-IR was observed in some NAAG-containing fiber tracts including the corpus callosum, fornix, Habenular Commissure, solitary tract, stria medularis, and stria terminalis.  

These findings suggest first, that the fibers from the neuro-receptors located in either the ventral or the dorsal olfactory mucosae project to both olfactory bulbs, and second, that the left and right bulbs exert a constant inhibition on each other via the Habenular Commissure..  

In the left ganglion at the caudal level, the dorsal and ventral bundle extended medially and joined the same bundle of the opposite side to constitute a dorsal and intermediate component of the Habenular Commissure, respectively.  

A few nerve fibers were observed in the Habenular Commissure and the pineal stalk, but no fibers were identified in the superficial pineal.  

These fibers cross in the Habenular Commissure and terminate in the contralateral cortical amygdaloid nucleus and periamygdaloid part of the lateral cortex.  

Small bundles of thin immunoreactive unmyelinated and thick immunoreactive myelinated nerve fibers occurred in the proximal pineal, especially near the Habenular Commissure. Axon-like processes of pinealocytes terminated on dendrites of immunonegative neurons present near the posterior and Habenular Commissures.  

Another group of labelled fibers extends, throughout the lateral and ventral walls, to the most caudal part of the telencephalon, and, through the stria medullaris and the Habenular Commissure, crosses over to the controlateral hemisphere.  

From the posterior commissure, some nerve fibers turned dorsally and entered into the deep pineal gland, a part of the pineal complex located in between the posterior and the Habenular Commissure.  

The Habenular Commissure shows much interspecific variation in its course through the pineal.  

The existence of the highest levels of pineal IRS near the Habenular Commissure, where the afferent fibers of the central pinealopetal innervation enter the gland, suggests that pineal somatostatin may be, at least in part, of neural origin..  

The pineal tract courses caudally along the left side of the Habenular Commissure, and a few fibers penetrate the brain through the caudalmost portion of this commissure.  

Its response disappeared after section of the olfactory interbulbar adhesion but was not affected by sectioning through either the anterior or the Habenular Commissure.  

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.  

Labelled fibers apparently arising from these neurons travelled in the stria medullaris and the Habenular Commissure to terminate in the contralateral basal forebrain.  

The MOB and AON project via the Habenular Commissure (HC) to the contralateral medial wall of the telencephalon.  

The intraventricular blood vessels appeared to be derived from the choroid plexus, and typically took one of three courses in and around the surface of the deep pineal: (1) the vessels or their equivalent were located in the suprapineal recess with no indication of penetration into the substance of the deep pineal; (2) the vessels coursed from the suprapineal recess around the anterior surface of the Habenular Commissure to enter the ventral surface of the deep pineal; or (3) the vessels entered the parenchyma of the deep pineal from its dorsal surface and could be seen coursing through the substance of the gland.  

Our findings also suggested that the L-ENKI fibers in the BZHb are supplied via the stria medullaris with an ipsilateral predominance and that, at the most caudal level, they arise not only from the ipsilateral stria medullaris but also from the contralateral stria medullaris via the Habenular Commissure..  

The pineal lies deep beneath the hemispheres adjacent to the third ventricle and is traversed by the Habenular Commissure anteriorly.  

Variable relationships between the pineal and the Habenular Commissure suggest that they may be unrelated functionally..  

In people older than 30 years, calcification in the pineal region including pineal body and Habenular Commissure was found in about 70%.  

Numerous peroxidase-positive fibers were observed, ipsilateral to the injection site, in the stria medullaris thalami and could be followed into the medial habenular nucleus and the Habenular Commissure.  

fibers cross to contralateral targets in the anterior commissure, the optic chiasma, the horizontal commissure, the posterior commissure, and possibly the Habenular Commissure.  

The olfactory bulb projects to subpallial and pallial areas in the ipsilateral telencephalon; a projection to the contralateral subpallium is noted via the Habenular Commissure.  

As the extrapineal portion of the Habenular Commissure was found to contain melatonin there is a possibility that melatonin may be taken up when the commissural fibres pass through the pineal parenchyma..  

Cells containing immunoreactive SP were located in the medial habenula, and SP fibers were observed in the lateral habenula, Habenular Commissure, pineal stalk, and the pineal organ.  

Contralateral projections cross in rostral and caudal portions of the anterior commissure and in the Habenular Commissure.  

A conspicuous nerve tract containing approximately 350 fibers arises from the parapineal organ and runs in spatial relationship to the Habenular Commissure toward the left habenular nucleus.  

Using fetuses ranging in age from 13.0 to 18.0 days, the general order or arrival of fibre tracts at midplane is: posterior commissure, optic chiasm, stria terminalis, Habenular Commissure, columns of the fornix, anterior commissure, hippocampal commissure and corpus callosum.  

Entopeduncular and lateral hypothalamic axons passed through the Habenular Commissure to the contralateral stria medullaris to reach the contralateral LHB.  

Some nerve fibers decussate within the Habenular Commissure.  

However, the Habenular Commissure has typical commissural fibres which apparently do not involve the medial portion of the left habenula.  

Both intracerebroventricular injection of 5,7-dihydroxytryptamine and electrolytical midbrain-raphe lesions in rats induce degeneration of supraependymal axons (SEAs) normally occurring in large numbers upon the ependyma of the medial habenular nucleus and Habenular Commissure.  

The habenular diameters in the plane of the Habenular Commissure are in the range between 81 and 88% of the control measurements.  

Vasopressin and oxytocin fibres extend via the subcommissural organ or Habenular Commissure into the pineal stalk and terminate in the anterior part of the pineal organ.  

Posterior to the Habenular Commissure several small branches run out laterally from the ventral bundles to the basal margin of the ependyma, but not into the Habenular Commissure.  

The medial habenular nucleus, the intercommissural and suprahabenular recesses, the Habenular Commissure and the fibrae periventriculares thalami have the greatest density of SN/100micron of ependymal surface.  

There were also observed many fibers of passage which ran between the SM and FR, or between the Habenular Commissure (HC) and FR.  

In addition, some axons enter the ipsilateral stria medullaris thalami, cross the midline in the Habenular Commissure, enter the contralateral stria medullaris thalami and terminate in the contralateral lateral pallium.  

Two crossed secondary olfactory pathways to the contralateral telencephalon decussate via the Habenular Commissure after entering the ipsilateral stria medullaris.  

Degeneration was seen in the Habenular Commissure and bilaterally in the habenula and fasciculus retroflexus, but was most extensive ipsilaterally.  

A nerve from the parietal eye of the western fence lizard, Sceloporus occidentalis, is described as leaving inconspicuously from the third-eye and extending caudally under the dura mater and then ventrally along the left anterolateral surface of the epiphysis to the Habenular Commissure of the brain.  

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