Susceptibility of neurons in area 18a to blockade of area 17 in rats.
The present investigation is aimed at studying the influence of the striate cortex (area 17 or V1) upon responses of area 18a. Electrical activity was recorded from neurons in area 18a through glass micropipettes. At the same time lidocaine hydrochloride was injected in the same retinotopic register of area 17. Forty eight cells were tested to diffuse stroboscopic flashes and to localized stationary or moving slits in the receptive field. In addition, orientation selectivity was analyzed in 15 units. Blockade of area 17 produced the following results: discharges to stroboscopic light were unaltered while responses to stationary, localized targets were diminished in about half of the cells. Fifty percent of movement evoked responses were decreased. The orientation properties were particularly sensitive to blockade of area 17. Out of 15 units, 13 had their orientation tuning curves altered by the treatment. These results seem to suggest that the degree of trigger feature complexity depends upon lateral interactions between areas V1 and V2.
Molotchnikoff
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S
Centre de Recherche en Sciences Neurologiques, Université de Montréal, Département de Sciences Biologiques, Qué., Canada.
Hubert
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F
D000818:Animals; D005074:Evoked Potentials, Visual; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation; D051381:Rats; D014793:Visual Cortex / Q000502:physiology*