Contribution of GABA receptors to extinction of memory traces in normal conditions and in a depression-like state.

A relationship between the effects of activation and blockade of GABA receptors on extinction of a conditioned passive avoidance reaction on the one hand and the type of receptor and initial psychoemotional state on the other was found in mice. Activation of GABA(A) receptors with muscimol impaired extinction in normal conditions but had no effect on the delay in this process in mice with "behavioral despair" reactions. Activation of GABA(B) receptors with baclofen accelerated extinction of the memory of fear in mice with the depression-like state. Blockade of GABA(A) receptors with bicuculline had no extinction-modifying effect. Blockade of GABA(B) receptors with faclofen promoted retention of the expression of fear in intact mice and acceleration of extinction in "depressed" mice.