Studies of the Role of Serotonin-Modulating Anticonsolidation Protein in Memory Formation in Rats in a Shuttle Box

Abstract

Two series of experiments were performed on male Wistar rats. In the first series, rats were trained to a conditioned reflex skill in a shuttle box to the 50% and 80% learning criteria. A significant reduction in the level of serotonin-modulated anticonsolidation protein (SMAP) was observed in the parietal area of the cortex in animals of the experimental group reaching the 50% learning criterion and in the occipital and parietal areas of the cortex in animals of the experimental group reaching the 80% learning criterion, as compared with animals of the active control group. In the second series of experiments, animals of the experimental group received daily serotonin-modulated anticonsolidation protein at a concentration of 1.5 mg/ml in physiological saline (10 μl) via a cannula implanted into the left lateral ventricle of the brain 40 min before training sessions. Control animals were given the same quantity of heat-inactivated protein. Training was performed in a shuttle box for a period of several days to the 50% learning criterion. These experiments showed that rats of the experimental group reached the learning criterion in seven days, while intact and control animals reached this level in four days. In addition, animals of the experimental group differed in having increased levels of fear, anxiety, and aggressivity, which did not decrease throughout the training period. These results led to the conclusion that serotonin-modulated anticonsolidation protein is involved in the negative regulation of memory trace formation in nerve cells.