Effects of reserpine on retention of escape reversal in mice: Absence of state-dependent learning

Used a discriminated escape training paradigm in 4 experiments to study the effects of reserpine (RE) on learning and memory in 465 male Swiss mice. Injection of RE (ip) before reversal training had no effect on acquisition but did produce a time- and dose-dependent impairment of retention 10 days later. These results suggest that RE may have interfered with some aspect of memory storage. Retention impairments observed when a 2.0 mg/kg RE injection was given 2 hrs before reversal training were not attenuated by readministering the drug before testing, a finding that provides no support for a state-dependency interpretation. Furthermore, Ss treated with RE exhibited inferior retention of previous training, regardless of the pharmacological state present during that learning. This was interpreted as a drug-induced impairment of memory retrieval. In addition, performance during the initial discriminated escape training session suggested that RE may also impair acquisition under some conditions. In the last experiment, it was found that when the catecholamine precursor l -dihydroxyphenylalanine (100 mg/kg) and the indole amine precursor d,l -5-hydroxytryptophan (125 mg/kg) were both given after RE treatment, subsequent retention performance was not significantly impaired. Results are discussed in terms of the possible roles of biogenic amines in arousal, learning, and memory. (38 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).