GABA-induced inactivation of Cebus apella V2 neurons: effects on orientation tuning and direction selectivity
Braz. j. med. biol. res
;
46(7): 589-600, ago. 2013. graf
Article
in English
| LILACS
| ID: lil-682401
ABSTRACT
We investigated the GABA-induced inactivation of V2 neurons and terminals on the receptive field properties of this area in an anesthetized and paralyzed Cebus apella monkey. Extracellular single-unit activity was recorded using tungsten microelectrodes in a monkey before and after pressure-injection of a 0.25 or 0.5 M GABA solution. The visual stimulus consisted of a bar moving in 8 possible directions. In total, 24 V2 neurons were studied before and after blocker injections in 4 experimental sessions following GABA injection into area V2. A group of 10 neurons were studied over a short period. An additional 6 neurons were investigated over a long period after the GABA injection. A third group of 8 neurons were studied over a very long period. Overall, these 24 neurons displayed an early (1-20 min) significant general decrease in excitability with concomitant changes in orientation or direction selectivity. GABA inactivation in area V2 produced robust inhibition in 80% and a significant change in directional selectivity in 60% of the neurons examined. These GABA projections are capable of modulating not only levels of spontaneous and driven activity of V2 neurons but also receptive field properties such as direction selectivity.
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Orientation
/
Visual Cortex
/
GABA Agents
/
Gamma-Aminobutyric Acid
/
Neural Inhibition
/
Neurons
Limits:
Animals
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
2013
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Universidade Federal do Para/BR
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