[GABA-opioid interaction during the recovery of a passive avoidance conditioned reaction]

The modulating influence of preliminary activation of the delta-opiate receptors on retrieval and retention of the memory trace during the blockade of various components of GABA-benzodiazepine-ionophore complex in a passive avoidance paradigm was studied in mice. The psychogenic amnesia was caused by a detention of a mouse in the dangerous compartment. Bicuculline (1 mg/kg), picrotoxin (1 mg/kg) and flumazenil (10 mg/kg) injected prior to testing attenuated the retrieval deficit caused by amnesia. Pretraining administration of leu-enkephalin (0.2 mg/kg) facilitated the efficiency of the action of the blockade of benzodiazepine receptors on the retrieval of the passive avoidance response whereas the blockade of GABA-A receptors and chloride channels was non-effective. These experiments provide additional support for the hypothesis that "neurochemical set" plays an important role of a regulator determining the neurochemical interaction between opiate receptor and GABA-benzodiazepine-ionophore complex in modulating memory processes.