RESUMO
In experiments on rats with tests for avoidance of an "illuminated area" and a "threatening situation", microinjection into the septal nucleus accumbens of monoamines and GABA, adreno- and dopaminomimetics, and their antagonists demonstrated a different neurochemical profile of this brain structure in anxiety states of different genesis. Local injections of chlordiazepoxide, pnenibut, indoter, campiron, and campironin into the nucleus weakened the alarm in the test for avoidance of an "illuminated area" and/or a "threatening situation", showing a similarity to the effects of GABA and serotonin but not to those of mesaton (phenylephrine hydrochloride) and dopamine. It is concluded that the antialarm effect of benzodiazepine and nonbenzodiazepine anxiolytics may be mediated by switching into action of neuron matrices of the accumbens nucleus with a different neurochemical profile responsible for the operative control of behavior in changed modality of the aversive stimulus.
