Biomaterial Database

Effect of the richness of the environment on neurons in cat visual cortex. I. Receptive field properties. 1990

C Beaulieu, and M Cynader

Department of Psychology, Dalhousie University, Halifax, N.S. Canada.

In a recent study, it was demonstrated that the number of synaptic contacts associated with flat vesicles (FS synapses) is higher in the visual cortex of cats raised in an enriched environmental condition (EC) compared to those reared in an impoverished condition (IC). Moreover, the size of the FS synaptic contacts is also affected by the richness of the animal's environment during development. Based on evidence that the vast majority of FS synapses are GABAergic (gamma-aminobutyric acid) and that many of the properties of visual cortex neurons are influenced by GABA-dependent mechanisms, it has been suggested that these morphological synaptic changes induced by the richness of the environment correlate with differences in cortical receptive field properties. In the present study, this has been explored by recording visual responses of area 17 cells in cats raised either in isolation (IC) or in a colony with ample environmental stimulation (EC). Enriched visual cortex contains a higher proportion of orientation selective cells and a lower proportion of orientation biased and unoriented cells. In addition, orientation tuning is significantly sharper in EC animals (mean bandwidth of responsive units is equal to 32 degrees) than in IC cats (mean bandwidth is equal to 38 degrees; P less than 0.001). This is mostly due to the greater incidence of orientation biased units in impoverished cortex (23% in EC and 41% in IC animals; P less than 0.01). Unit responsivity is significantly affected by the richness of the environment. We found that all units of the EC cortex were responsive to light stimuli. In contrast, 14% of the impoverished cells studied fail to increase their response to at least twice the standard deviation of the spontaneous activity and were judged as unresponsive. We suggest that the lower responsivity in IC visual units is related to the higher number of GABAergic synapses per IC neuron, while the broader selectivity in IC cortex might be due to a more diffuse distribution of the GABAergic inhibitory connections.

UI	MeSH Term	Description	Entries
D007839	Functional Laterality	Behavioral manifestations of cerebral dominance in which there is preferential use and superior functioning of either the left or the right side, as in the preferred use of the right hand or right foot.	Ambidexterity,Behavioral Laterality,Handedness,Laterality of Motor Control,Mirror Writing,Laterality, Behavioral,Laterality, Functional,Mirror Writings,Motor Control Laterality,Writing, Mirror,Writings, Mirror
D008297	Male		Males
D009039	Motion Perception	The real or apparent movement of objects through the visual field.	Movement Perception,Perception, Motion,Perception, Movement
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
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
D005260	Female		Females
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
D012931	Social Environment	The aggregate of social and cultural institutions, forms, patterns, and processes that influence the life of an individual or community.	Social Context,Environment, Social,Social Ecology,Context, Social,Contexts, Social,Ecologies, Social,Ecology, Social,Environments, Social,Social Contexts,Social Ecologies,Social Environments
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
D014794	Visual Fields	The total area or space visible in a person's peripheral vision with the eye looking straightforward.	Field, Visual,Fields, Visual,Visual Field