[The tuning of striate neurons to cross-like figures during local blockade of intracortical inhibition].
Many neurons in the cat primary visual cortex reveal sensitivity to cruciform and corner figures as well as to local orientation discontinuities. We investigated this sensitivity in 85 V1 neurons before and after the local blockade of GABA(A)ergic inhibition by microiontophoretic application of bicuculline and observed two opposite effects: a decrease or disappearance of sensitivity to crosses in about half of the neurons and its increase or appearance in about one third of the units. The results indicate substantial and drastically different contribution of intracortical inhibition to sensitivity to line-crossings in the visual cortical neurons. Some possible mechanisms of this difference are discussed.
Shevelev
I A
IA
Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia.
Eysel
U T
UT
Jirmann
K U
KU
Sharaev
G A
GA
D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D002415:Cats; D018756:GABA Antagonists / Q000494:pharmacology; D058787:GABA-A Receptor Antagonists; D008839:Microelectrodes; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011963:Receptors, GABA-A / Q000187:drug effects / Q000502:physiology; D014793:Visual Cortex / Q000187:drug effects / Q000502:physiology*
D018756:GABA Antagonists; D058787:GABA-A Receptor Antagonists; D011963:Receptors, GABA-A; D001640:Bicuculline