(1) The number of axons displaying peptide-like immunoreactivity within the optic nerve, retinal or cerebral to the crush, and within the optic chiasm gradually decreased after 2-3 months.
(2) Optic chiasm transection drastically diminished this ability, callosal section had little effect and combined lesions of these two structures abolished stereoperception.
(3) Two patients with sphenoethmoid mucoceles developed visual field defects consistent with optic chiasm dysfunction.
(4) We studied a family in which the proband had an acute chiasmal syndrome secondary to a cavernous angioma of the optic nerve and chiasm.
(5) We describe a case of ganglioglioma of the optic chiasm and tract in a 33-year-old man.
(6) Since such rats supposedly have a normal pigment distribution and a normal pattern of decussation at the optic chiasm, this finding appears to undermine the suggested role played by stalk melanin in establishing the laterality of retinal fibre projections in other mammalian species.
(7) In addition to a severe disorganization of the inner optic chiasm irreC mutants display a subtle phenotype in the outer optic chiasm, in which some bundles of axons that leave the posterior equatorial part of the lamina on their way to the anterior medulla take a long detour before eventually finding their specific targets in the medulla neuropile.
(8) Such fibers were observed to leave the posterior medial portion of the optic chiasm and, after arching dorsally, to project into the posterior fifth of the suprachiasmatic nucleus (SCN), as well as into the rostral part of the arcuate nucleus.
(9) There was no fascicular organisation at the point at which the two nerves fused at the chiasm.
(10) Following microneurosurgical decompression of the optic nerves and chiasm, prompt visual recovery occurred.
(11) We describe a young girl with neurofibromatosis and enlargement of the optic chiasm and intracranial left optic nerve.
(12) A pilocytic astrocytoma of the optic nerve, chiasm, hypothalamus, or third ventricle is a relatively common tumor of childhood.
(13) In the developing mammalian visual system, retinal fibers grow through the optic chiasm, where one population crosses to the opposite side of the brain and the other does not.
(14) Other cats that learned the same discriminations monocularly but had sustained a combined section of optic chiasm and forebrain commissures before learning showed no indication of interocular transfer.
(15) However, the mean response latency to stimulation of the optic chiasm was significantly shorter for Y cells in MIN than for Y cells in the laminated LGNd.
(16) Four of these groups may be related to four negative peaks seen in the antidromic compound action potential recorded at the margin of the cat optic disc following stimulation of the optic chiasm.
(17) Although parabrachial activation by itself had no detectable effect on Y cell response modes, prior parabrachial activation prevented the enhanced burstiness caused by chiasm stimulation.
(18) The frontal basal cisterns could not be filled sufficiently with the contrast agent due to haematoma and a prefixed chiasm accompanied by arachnoid adhesions in two cases.
(19) Similar results were found in cats and kittens that underwent only chiasm split surgery, although some recovery of callosal transfer was found in the latter.
(20) The structures of the developing eye-stalk and the relationships of early retinofugal fibers as they pass through the stalk, chiasm, and tract have been studied by light and electron microscopical methods in fetal ferrets aged 23-27 days.
Chiasma
Definition:
(n.) A commissure; especially, the optic commissure, or crucial union of the optic nerves.
Example Sentences:
(1) For the case described by the author primary tearing of the chiasma due to sudden applanation of the skull in the frontal region with burstfractures in the anterior cranial fossa is assumed.
(2) There were, however, significant differences among investigators in reported mean chiasma frequencies.
(3) In only one case was the B chromosome significantly associated with an increase chiasma frequency.
(4) Chromosomal analysis of cells undergoing diakinesis showed significantly lower chiasma frequency in elderly men, compared with a group of younger control males and also with infertile males.
(5) Furthermore we found increased chiasma frequencies in diakinesis--metaphase I (MI) and reduced nondisjunction frequencies at anaphse I as a result of the treatments applied.
(6) A case of cystic optic glioma involving chiasma and bilateral posterior optic pathway was reported.
(7) CT revealed a calcified lesion which must be a vessel in the chiasma cistern just adjacent to the basilar artery which was relatively larger than normal.
(8) In the unanaesthetised animals the proportions of units responding were high (60%) and did not differ significantly between regions for each type of stimulation investigated: visual, auditory and optic chiasma shocks.
(9) Tangential, centrifugal and incerta sedis-fibres, which originate either from cell bodies in the cell body layer at the periphery of the outer chiasma or more centrally, terminate in the synaptic region of the lamina.
(10) This new function is derived by assuming that all chromosome arms except the short arms of acrocentric chromosomes hav an obligatory chiasma, and that the remaining chiasmata are distributed at random; assumptions which may correspond reasonably well to reality.
(11) Thus from just beyond the chiasma the fibres had already achieved the major uniaxial rearrangement necessary to establish a normal tract distribution despite the eye translocation.
(12) Pathologically there was necrosis of the optic chiasma and focal areas of myelin sheath vacuolation or demyelination in certain areas of the brain, especially in the cerebellar peduncles.
(13) Predictions from the chiasma map can be confirmed or refuted only by genetic evidence for which the estimates of this paper serve as initial values to begin maximum likelihood iteration.
(14) Male meiosis in Mesostoma ehrenbergii ehrenbergii (2x = 10) is characterized by extreme restriction of chiasma formation; 3 pairs of chromosomes form bivalents at metaphase I which are associated by single very distally localized chiasma, while two pairs of chromosomes remain as unpaired univalents.
(15) It was found that both of the heat-induced decreases in chiasma frequency which can be obtained (Effects 2 and 3), were dominant over both of the different types of increase (Effects 1 and 4), with the largest decrease (Effect 3) being dominant over all others.
(16) In precocious puberty we found 1 ectopic pinealoma and 2 gliomas of the chiasma.
(17) The latter refers to the Willis atypical polygons, which determine important atipies in the topographical distribution of the chiasma's arteries and optical bandelets.
(18) In the rostral third of the SCN there are relatively few optic synapses which are found close to the optic chiasma.
(19) In addition to this abnormality there is a misrouting of the optic nerve fibers, with some fibers from the temporal retina following a crossed route at the chiasma and terminating in the contralateral cortical hemisphere.
(20) The chiasma frequency estimates were based on 15 son-sire pairs, the translocation heterozygotes being maintained in a Swiss random-bred genetic background.