Biphasic effects of adrenal steroids on learned helplessness behavior induced by inescapable shock.

KADEMIAN SILVIA MARÍA; BIGNANTE ELENA ANAHI; LARDONE PATRICIA; MCEWEN BRUCE; VOLOSÍN MARTA

NEUROPSYCHOPHARMACOLOGY

Nature Publishing Group,

Año: 2005 vol. 1 p. 58 - 58

0893-133X

font face="AdvGillSan-L" size="1"> ABSTRACT Corticosterone (CS) has been shown to regulate behavior in the learned helplessness (LH) paradigm. Here we provide evidence for a Ushaped relationship between the increasing doses of CS administered and escape failures in the LH model. Replacement with CS (20– 400 mg/ml in drinking water) in adrenalectomized (ADX) animals was utilized to examine how the selective activation of mineralocorticoid (MR) and glucocorticoid (GR) receptors is related to the behavioral impairments induced by inescapable shock (IS). Available MR and GR levels were determined in hippocampal cytosol by radioligand binding assays. Non-CS replaced ADX animals s