[The mechanisms of the anxiolytic action of 1-(2-pyrimidinyl)-piperazine derivatives, serotonin agonists].

1-(2-pyrimidinyl)-piperazine derivatives (ipsapirone and campirone) injected intraperitoneally or into dorsalis nucleus raphe and dorsalis hippocampus of rats revealed dose-dependent anxiolytic action in avoidance procedure and conflict situations. 5-HT locally injected into the nucleus raphe and hippocampus revealed a role of serotoninergic mechanisms of these brain formations in the studied anxiety conditions of different aversive genesis. It is concluded that anxiolytic effect dissociation revealed in different anxiety tests, are stipulated by serotonin and its agonists due to nucleus raphe and hippocampus chemical stimulation my suggest their different neurochemical contribution and nonserotoninergic component involved in the mechanism of 1-(2-pyrimidinyl)-piperazine derivative anxiolytic action.