Biomaterial Database

The transfer of visual information across the corpus callosum: spatial and temporal properties in the cat. 1987

N Berardi, and S Bisti, and L Maffei

Istituto di Neurofisiologia del C.N.R., Pisa, Italy.

1. The spatial and temporal characteristics of the visual information transmitted across the corpus callosum have been studied in normal cats by recording directly from the corpus callosum and in split-chiasm cats by means of visual evoked potentials (v.e.p.s) and single-unit recordings at the 17/18 border. 2. The modulation transfer functions (m.t.f.s) obtained by recording from the corpus callosum are comparable to the m.t.f.s evaluated by various techniques for the whole visual system of the cat. The spatial and temporal acuities, however, do not reach the values obtained behaviourally or estimated with cortical evoked potentials. 3. In split-chiasm cats, both v.e.p.s and single-unit recordings indicate that the contrast gain of the callosal pathway is considerably lower than the gain of the direct, geniculo-cortical system. Spatial and temporal acuities are lower for the callosal than for the direct system. 4. The same differences in contrast gain between the spatial m.t.f. obtained for the callosal and the direct system have been found in alert split-chiasm cats. 5. Our data suggest that the cross-talk between the hemispheres taking place across the corpus callosum is nearly abolished at low contrasts and high spatial and temporal frequencies.

UI	MeSH Term	Description	Entries
D009897	Optic Chiasm	The X-shaped structure formed by the meeting of the two optic nerves. At the optic chiasm the fibers from the medial part of each retina cross to project to the other side of the brain while the lateral retinal fibers continue on the same side. As a result each half of the brain receives information about the contralateral visual field from both eyes.	Chiasma Opticum,Optic Chiasma,Optic Decussation,Chiasm, Optic,Chiasma Opticums,Chiasma, Optic,Chiasmas, Optic,Chiasms, Optic,Decussation, Optic,Decussations, Optic,Optic Chiasmas,Optic Chiasms,Optic Decussations,Opticum, Chiasma,Opticums, Chiasma
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D003337	Corpus Callosum	Broad plate of dense myelinated fibers that reciprocally interconnect regions of the cortex in all lobes with corresponding regions of the opposite hemisphere. The corpus callosum is located deep in the longitudinal fissure.	Interhemispheric Commissure,Neocortical Commissure,Callosum, Corpus,Callosums, Corpus,Commissure, Interhemispheric,Commissure, Neocortical,Commissures, Interhemispheric,Commissures, Neocortical,Corpus Callosums,Interhemispheric Commissures,Neocortical Commissures
D005074	Evoked Potentials, Visual	The electric response evoked in the cerebral cortex by visual stimulation or stimulation of the visual pathways.	Visual Evoked Response,Evoked Potential, Visual,Evoked Response, Visual,Evoked Responses, Visual,Potential, Visual Evoked,Potentials, Visual Evoked,Response, Visual Evoked,Responses, Visual Evoked,Visual Evoked Potential,Visual Evoked Potentials,Visual Evoked Responses
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013028	Space Perception	The awareness of the spatial properties of objects; includes physical space.	Perception, Space,Perceptions, Space,Space Perceptions
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor