Presynaptic GABAA Receptors Modulate Thalamocortical Inputs in Layer 4 of Rat V1

• Published in: Cerebral cortex (New York, N.Y. 1991) Vol. 29; no. 3; pp. 921 - 936
• Main Authors: Wang, L, Kloc, M, Maher, E, Erisir, A, Maffei, A
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 01.03.2019
• Subjects: Animals; Female; Geniculate Bodies - physiology; Glutamic Acid - physiology; Male; Neural Pathways - physiology; Neurons - physiology; Presynaptic Terminals - physiology; Rats; Receptors, GABA-A - physiology; Synaptic Transmission; Visual Cortex - physiology; GABA; synaptic transmission; visual cortex; thalamocortical; corticothalamic
• ISSN: 1047-3211; 1460-2199
• DOI: 10.1093/cercor/bhx364

Abstract Fast inhibitory GABAergic transmission plays a fundamental role in neural circuits. Current theories of cortical function assume that fast GABAergic inhibition acts via GABAA receptors on postsynaptic neurons, while presynaptic effects of GABA depend on GABAB receptor activation. Manipulations of GABAA receptor activity in vivo produced different effects on cortical function, which were generally ascribed to the mode of action of a drug, more than its site of action. Here we show that in rodent primary visual cortex, α4-containing GABAA receptors can be located on subsets of glutamatergic and GABAergic presynaptic terminals and decrease synaptic transmission. Our data provide a novel mechanistic insight into the effects of changes in cortical inhibition; the ability to modulate inputs onto cortical circuits locally, via presynaptic regulation of release by GABAA receptors.