REVEALING LATENT TRACES IN THE HIPPOCAMPU S AFTER CESSATION OF LONG-TERM POTENTIATION

The possibility of restoration of long-term potentiation (LTP) due to stimulation of the locus coeruleus and the dorsal raphe nucleus was in vestigated in the dentate gyrus and the area CA1 of the hippocampus co rrespondingly. The stimulation parameters were sufficient to evoke beh avioural reactions of the freely moving rats. It was shown that the st imulation of the locus coeruleus non-effective before tetanization of the perforant path restored the already cessated LTP in the dentate gy rus evoked by tetanization of the perforant path. Also, the stimulatio n of the dorsal raphe nucleus non-effective before tetanization of the Schaffer collaterals restored the already cessated LTP in the area CA 1 evoked by tetanization of the Schaffer collaterals. The mathematical model of LTP restoration is presented based on the existence of sever al forms of calcium/calmodulin-dependent protein kinase. LTP restorati on due to stimulation of the emotiogenic brain structures is considere d as a model of emotional reminder phenomenon.