Cortistatin modulates memory processes in rats

Cortistatin (CST) is a recently described neuropeptide with high structural homolog with somotostatin. Its mRNA is restricted to gamma amino butyric a cid (GABA)-containing cells in the cerebral cortex and hippocampus, CST mod ulates the electrophysiology of the hippocampus and cerebral cortex of rats : hence, it may be modulating mnemonic professes. In this study, we have ev aluated the effect of CST and somatostatin (SS) on short- and long-term mem ory (STM and LTM, respectively), as well as on the extinction of the behavi or by using the footshock passive avoidance behavioral test. In addition, w e tested the ability of both neuropeptides to affect the generation of cAMP in hippocampal neurons in culture. Results showed that the administration of either CST or SS into the hippocampal CA1 deteriorates memory consolidat ion in a dose-response fashion and facilitates the extinction of the learne d behavior. CST was more potent than SS. Likewise. CST increases cAMP while SS decreases it. These results strongly support a modulatory role fur CST in memory processes. (C) 2000 Elsevier Science B.V. All rights reserved.