Lack of feedback inhibition on rat basolateral amygdala following stress or withdrawal from sedative-hypnotic drugs

BERTOTTO, MARIA E.

EUROPEAN JOURNAL OF NEUROSCIENCE

WILEY-BLACKWELL PUBLISHING, INC

Año: 2007 vol. 26 p. 1036 - 1036

0953-816X

revious research has demonstrated that suppression of inhibition in projection neurons of the basolateral complex of the amygdala (BLA) represents an essential mechanism underlying the emergence of negative emotional responses, including exaggerated fear and anxiety. The present work evaluates inhibitory postsynaptic potentials (IPSPs) in pyramidal projection neurons of the BLA in rats subjected to either diazepam or ethanol withdrawal or uncontrollable stress. These are experimental paradigms conducive to a negative emotional state. In slices containing the BLA, IPSPs were studied using whole-cell patch clamp. In control animals, a small IPSP was evoked by sub-threshold stimulation of the external capsule. When an action potential (AP) was evoked by supra-threshold stimuli, IPSPs were considerably larger; these IPSPs were sensitive to blockade of GABAA receptors by picrotoxin. However, IPSPs were clearly reduced in diazepam- or ethanol-withdrawn and in stressed rats. Firing of an AP