Modification of the behavioral effects of corticoliberin by early post-natal administration of corticosteroid hormones.

Experiments on rats in which hydrocortisone was given in the early postnatal period were used to study the effects of intrastriatal microinjection of corticoliberin on behavior in an open field test. Bilateral microinjection of corticoliberin into the neostriatum led to a sharp reduction in orientational-investigative activity. Rats given hydrocortisone in the first days of life had elevated movement activity, and the anxiogenic effect of corticoliberin was absent in these animals.