Effect of serotonin-modulated anticonsolidation protein on formation of long-term memory in the learning model of active avoidance in the carp (Cyprinus carpio)

Effects of serotonin-modulated anticonsolidation protein (SMAP) that has property to impair formation of memory trace in mammals and of learning and memory in teleost fish was studied in the learning model of active avoidance. The experiment was performed in three stages: (1) fry of carp Cyprinus carpio L. was injected intracerebroventricularly with the SMAP at a dose of 0.3 μg/g; control individuals were administered with equal amount of the buffered saline for poikilothermic animals; (2) 24 h after injection, fish were learned the conditioned reflex of active avoidance; (3) 48 h after the learning the testing of the skill was perfomed. The administration of the protein was shown to lead to impairment of reproduction of the skill in the fish: the latent time of the skill reproduction in experimental individuals exceeded that in control fish more than two times, while the number of individuals succeeding the task in the expreimental group was insignificantly lower than in the control group. However, unlike mammals, injection of the SMAP in this model produced no effect on the process of learning in carps. Thus, there was first demonstrated the inhibiting effect of the SMAP whose concenration correlated positively with the content of the neurotransmitter serotonin in brain on consolidation of memory traces in teleost fish.