Neurochemical and behavioral consequences of mild, uncontrollable shock: effects of PCPA.
The present experiments examined the role of the serotonergic system in the behavioral deficit produced by uncontrollable shock. In Experiment 1: Establishment of model, the behavioral potential of the Sprague-Dawley rat was defined. When exposed to mild uncontrollable stress such as a 0.8 mA electric footshock, a significant percentage of rats developed a shock escape deficit which was evident when subsequently placed in a shock escape paradigm. Serotonin depletion was produced by chronic treatment with p-chlorophenylalanine. Biogenic amine levels and 5-HT levels were monitored in various brain areas using HPLC. Following chronic treatment with PCPA, the shock escape capability of the Sprague-Dawley rat was assessed. The severe depletion of 5-HT in various brain regions was highly correlated with a dramatic improvement in the shock escape scores. Thus, the detrimental effects of exposure to a mild course of inescapable shock can be prevented by chronic treatment with PCPA. These experiments implicate the serotonergic system as a possible mediator of the "learned helplessness" phenomenon.
D000818:Animals; D001679:Biogenic Amines / Q000032:analysis; D001921:Brain / Q000502:physiology*; D001923:Brain Chemistry / Q000187:drug effects; D004597:Electroshock; D010134:Fenclonine / Q000494:pharmacology*; D006380:Helplessness, Learned; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000032:analysis / Q000502:physiology*
D001679:Biogenic Amines; D012701:Serotonin; D010134:Fenclonine