A New Component in the Mechanism of Regulation of Endogenous Depressive-Like States.

It was shown previously that cycloprolylglycine, an endogenous neuropeptide, is a positive AMPA receptor modulator and is able to increase the content of BDNF in neurons. In the present study, using the model of learned helplessness in rats, we showed that cycloprolylglycine at a dose of 1 mg/kg at subchronic intraperitoneal administration reduced the time of animal immobility to passive control values (from 167.6 to 83.6 s) on day 12 of the experiment. This indicates the presence of antidepressant-like activity. The results of the study allow us to consider cycloprolylglycine as a component in the physiological regulation of the depression-like state.