title: Testosterone impairs the acquisition of an operant delayed alternation task in male rats.
abstract: The current study examined the effects of gonadectomy (GDX) and subsequent testosterone treatment of male Long-Evans rats on an operant variable delay spatial alternation task (DSA). Gonadally-intact rats (intact-B), GDX rats receiving implants that delivered a physiological level of testosterone (GDX-T), and GDX rats receiving blank implants (GDX-B) were tested for 25 sessions on a DSA task with variable inter-trial delays ranging from 0 to 18 s. Acquisition of the DSA task was found to be enhanced following GDX in a time and delay dependent manner. Both the GDX-T and the intact-B rats had lower performance accuracies across delays initially, relative to GDX-B rats, and this deficit persisted into subsequent testing sessions at longer delays. The GDX-T and intact-B rats also had a tendency to commit more perseverative errors during the early testing sessions, with both groups persisting in pressing a lever which had not been associated with reinforcement for at least two consecutive trials. However, both the GDX-T and intact-B groups were able to achieve performance accuracy similar to that of the GDX-B rats by the final sessions of testing. Overall, these results suggest that castration of adult male rats enhances their acquisition of an operant DSA task.
authors: Department of Comparative Biosciences, University of Illinois at Urbana-Champaign. 2001 S. Lincoln Avenue, Urbana, IL 61802, USA. stlneese@illinois.edu
authors: Steven L
authors: SL
authors: Neese
authors: Susan L
authors: SL
authors: Schantz
mesh_terms: D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects / Q000502:physiology*; D008297:Male; D009919:Orchiectomy; D051381:Rats; D020318:Rats, Long-Evans; D013739:Testosterone / Q000494:pharmacology / Q000502:physiology*
chemical_list: D013739:Testosterone