Abstract: We adopted the method of embeding the chronic canal in brain tomicroinject Acetylcholine and Atropine, GABA and Picrotoxin, L-Glutam-ate and receptor agonist kainic acid, Quinolinic acid, antagonist kynare-nic acid to dorsal hippocampus. The effects of such injection on the con-solidatory operant defence conditioning in rats were investigated. Theresults showed: (1 ) Acetylcholine, low concentration of picrotoxin, L-Glutamate,kainicacid and Quinolinic acid improved the complication of conditionedreflect activity. (2 ) Atropine, GABA and kynurenic acid impaired the above mentio-ned activity. These results suggested that some transmitter system in thehippocampus may be involved in memory retrieval modulation in rats.

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