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Relating to a commissure.
Farlex Partner Medical Dictionary © Farlex 2012


Relating to a commissure.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


(kom'i-shur?) [ commissura]
1. In the central nervous system, an axon tract that crosses the midline (sagittal) plane between two homologous and symmetric structures, e.g., the corpus callosum, which interconnects the right and left cerebral cortices.
2. The meeting of two structures, as the lips, eyelids, or labia, across the midline (sagittal) plane. commissural (kom?i-shur'al), adjective

anterior commissure

A symmetric axon tract running transversely through the lamina terminalis and connecting the right and left temporal cortices.

commissure of the fornix

Hippocampal commissure.

Gudden inferior commissure

See: Gudden inferior commissure

habenular commissure

A group of decussating axons of the stria medullaris. The stria medullaris contains axons projecting to the habenula from the septal nuclei, the preoptic hypothalamus, and the anterior thalamic nuclei; those stria medullaris axons that project to the contralateral habenula cross the midline plane via the habenular commissure.

hippocampal commissure

A thin sheet of axons from the fornix that cross the midline plane under the posterior sector of the corpus callosum and interconnect homologous fields of the right and left hippocampi.
Synonym: commissure of fornix

Meynert commissure

See: Meynert commissure

palpebral commissure

The union of the upper and lower eyelids at each end of the palpebral fissure.

posterior commissure

An axon tract running transversely through the gray matter that forms the roof of the cerebral aqueduct in the midbrain. This tract contains commissural axons interconnecting the right and left pretectal areas; it also contains decussating axons from each pretectal area to the contralateral Edinger-Westphal nucleus.

posterior commissure of spinal cord

The gray commissure connecting the halves of the spinal cord, lying behind the central canal.

tectal commissure

A symmetric axon tract running transversely through the ventral tectum of the midbrain and interconnecting the right and left superior colliculi.
Medical Dictionary, © 2009 Farlex and Partners
References in periodicals archive ?
These studies may also be of more direct relevance to regeneration in the adult spinal cord, as the chemoattractant may direct the growth not only of developing commissural axons but also of some classes of regenerating spinal axons.
Identification and characterization of a tachykinin-containing neuroendocrine organ in the commissural ganglion of the crab Cancer productus.
On the other hand, commissural calcification, significant subvalvular affection, in the presence of other unfavorable clinical characteristics would invite early surgical intervention.
In that line, 2 stimulation pulses were delivered to Schaffer commissural fibers at several interstimulus intervals (50,75,100,150,200, 300, and 400 ms).
It has been shown that CC genesisis triggered by these pioneer axons [39, 42-45]; pioneer axons are the first to form the path for the commissural neurons through interactions with several cues, including the midline structures, and on E17.0, the most early "follower" axons from layer V follow those of these pioneer neurons [42, 43, 46] (Figure 3(a)).
Upon examination of the valves with scanning electron microscope, the endothelium forming the valves was found to be altered especially at the commissural localization.
The neuropil is ultrastructurally distinct from the cerebral commissure because neurites of the commissure tend to have parallel trajectories as they extend between the two cerebral ganglia and commissural neurites lack large swellings filled with masses of electron-dense vesicles.
The origin of the putative inhibition remains to be determined, but could arise from the contralateral ear via commissural DON connections (6).
As pointed out by Pandya and Seltzer "The understanding of the precise topography for commissural fibers allows one to assess the nature of functional deficits following selective commissural lesions and to predict the localization of functions within cerebral commissural systems" [7].
Other identifiable spinal neuronal types (e.g., secondary motoneurons, Rohon Beard cells, dorsal root ganglion cells, circumferential descending (CiD) cells, commissural posterior ascending (CoPa) cells) and brain neurons (e.g., vestibulospinal neurons, nucleus of the medial longitudinal fasciculus) were also evident.
In the central nervous system of elasmobranchs, electrosensory reafference produced by ventilatory activity (gilling) is reduced through a common-mode rejection mechanism based upon commissural and unilateral local circuit neurons in the first-order medullary nucleus (Montgomery, 1984b; New and Bodznick, 1990; Bodznick and Montgomery, 1992).
Cheron, "Effect of incisions in the brainstem commissural network on the short-term vestibulo-ocular adaptation of the cat, " Journal of Vestibular Research, vol.

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