Post-training injections of catecholaminergic drugs do not modulate fear conditioning in rats and mice

Studies employing classical fear conditioning (F:C) and inhibitory avoidanc e (IA), two procedurally different aversive tasks, provide different insigh t into the neuronal mechanism(s) underlying fear learning. We examined whet her immediate post-training injections of catecholaminergic drugs modulate memory consolidation in one-trial FC, as has been demonstrated in one-trial IA. Neither epinephrine (0.1, 0.3, 1.0 mg/kg intraperitoneally) nor amphet amine (1.0, 2.0 mg/kg) modulates FC to tone or context, as indicated by fre ezing in rats. Similarly, epinephrine (0.1, 1.0 mg/kg) and P-adrenergic ant agonists (sotalol and propranolol; 2 mg/kg) also failed to modulate FC in m ice. These results indicate that FC is not susceptible to memory modulation by catecholaminergic drugs in the manner described in IA tasks. (C) 2001 E lsevier Science Ireland Ltd. All rights reserved.