| Abstract: | Two series of experiments were carried out in Wistar male rats. In the first series, rats were trained to acquire conditioning in a shuttle box to 50% and 80% learning criteria. In the animals of the experimental group that achieved 50% learning criterion, a significant decrease in the levels of serotonin-modulated anticonsolidation protein (SMAP) (solid phase, indirect ELISA-test) was observed in the temporal cortex as compared to the animals of the active control group. In the animals of the experimental group that achieved 80% learning criterion, such a decrease was found in the occipital and temporal cortex. In the second series of the experiments, animals of the experimental group were injected with SMAP in saline at a concentration of 1.5 mg/ml in a volume of 10 microl through the cannula implanted into the left lateral ventricle of the brain. Control animals were administered with heating-inactivated SMAP in the same amount. The substances were injected to the animals under light ether anesthesia daily 40 min prior to learning sessions. Learning sessions were carried out in the shuttle box for several days to 50% learning criterion. The experimental rats achieved learning criterion within 7-8 days, whereas intact and control animals reached the same criterion within 4 days. Furthermore, the experimental group of animals differed in increased levels of fear, anxiety and aggression which did not decline throughout the whole learning period. The conclusion was made that SMAP participated in negative regulation of the memory trace formation. |
