Biomaterial Database

The distribution of the cells of origin of callosal projections in cat visual cortex. 1982

M A Segraves, and A C Rosenquist

The distribution of neurons projecting through the corpus callosum (callosal neurons) was examined in retinotopically defined areas of cat visual cortex. As many callosal neurons as possible were labeled in a single animal by surgically dividing the posterior two-thirds of the corpus callosum and exposing the cut ends of callosal axons to horseradish peroxidase. The distribution of callosal neurons within a visual field representation was related to standard electrophysiological maps as well as to recording sites marked by electrolytic lesions. Callosal neurons were found in every retinotopically defined cortical area. The portion of the visual field representation that contained callosal neurons increased progressively from the area 17/18 border to area 19, to areas 20 and 21, and to the lateral suprasylvian visual areas. In area 17, the portion of the visual field representation containing callosal neurons extended from the vertical meridian out to a maximum of 10 degrees azimuth. In the posteromedial lateral suprasylvian visual area, callosal neurons were present in a region extending from the vertical meridian representation out to a representation of 60 degrees azimuth. Most callosal neurons were medium to large pyramids at the border of layers III and IV. A few layer IV stellates were among the callosal neurons of areas 17 and 18. In area 19 and even more so in the lateral suprasylvian visual areas, callosal neurons included pyramidal and fusiform-shaped cells in layers V and VI. The laminar distributions of callosal neurons in areas 20 and 21 were similar to those of area 19 and the lateral suprasylvian visual areas. The widespread distribution of callosal neurons in areas 20 and 21 and in the lateral suprasylvian visual areas suggests that the regions of peripheral visual field representation in cat cortex, as well as the representations of the vertical meridian, have access to the opposite cerebral hemisphere. This finding is significant in light of demonstrations of the importance of some of these cortical areas in the interhemispheric transfer of visual learning.

UI	MeSH Term	Description	Entries
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D012160	Retina	The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.	Ora Serrata
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
D004553	Electric Conductivity	The ability of a substrate to allow the passage of ELECTRONS.	Electrical Conductivity,Conductivity, Electric,Conductivity, Electrical
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D006735	Horseradish Peroxidase	An enzyme isolated from horseradish which is able to act as an antigen. It is frequently used as a histochemical tracer for light and electron microscopy. Its antigenicity has permitted its use as a combined antigen and marker in experimental immunology.	Alpha-Peroxidase,Ferrihorseradish Peroxidase,Horseradish Peroxidase II,Horseradish Peroxidase III,Alpha Peroxidase,II, Horseradish Peroxidase,III, Horseradish Peroxidase,Peroxidase II, Horseradish,Peroxidase III, Horseradish,Peroxidase, Ferrihorseradish,Peroxidase, Horseradish
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
D001370	Axonal Transport	The directed transport of ORGANELLES and molecules along nerve cell AXONS. Transport can be anterograde (from the cell body) or retrograde (toward the cell body). (Alberts et al., Molecular Biology of the Cell, 3d ed, pG3)	Axoplasmic Flow,Axoplasmic Transport,Axoplasmic Streaming,Axonal Transports,Axoplasmic Flows,Axoplasmic Transports,Streaming, Axoplasmic,Transport, Axonal,Transport, Axoplasmic,Transports, Axonal,Transports, Axoplasmic
D014793	Visual Cortex	Area of the OCCIPITAL LOBE concerned with the processing of visual information relayed via VISUAL PATHWAYS.	Area V2,Area V3,Area V4,Area V5,Associative Visual Cortex,Brodmann Area 18,Brodmann Area 19,Brodmann's Area 18,Brodmann's Area 19,Cortical Area V2,Cortical Area V3,Cortical Area V4,Cortical Area V5,Secondary Visual Cortex,Visual Cortex Secondary,Visual Cortex V2,Visual Cortex V3,Visual Cortex V3, V4, V5,Visual Cortex V4,Visual Cortex V5,Visual Cortex, Associative,Visual Motion Area,Extrastriate Cortex,Area 18, Brodmann,Area 18, Brodmann's,Area 19, Brodmann,Area 19, Brodmann's,Area V2, Cortical,Area V3, Cortical,Area V4, Cortical,Area V5, Cortical,Area, Visual Motion,Associative Visual Cortices,Brodmanns Area 18,Brodmanns Area 19,Cortex Secondary, Visual,Cortex V2, Visual,Cortex V3, Visual,Cortex, Associative Visual,Cortex, Extrastriate,Cortex, Secondary Visual,Cortex, Visual,Cortical Area V3s,Extrastriate Cortices,Secondary Visual Cortices,V3, Cortical Area,V3, Visual Cortex,V4, Area,V4, Cortical Area,V5, Area,V5, Cortical Area,V5, Visual Cortex,Visual Cortex Secondaries,Visual Cortex, Secondary,Visual Motion Areas