Testosterone increases analgesia, anxiolysis, and cognitive performance of male rats.
Preliminary evidence suggests that testosterone (T) may have anxiety-reducing and cognitive-enhancing properties in animals and people. Performance in a number of affective and cognitive behavioral tasks was examined in intact, T-depleted, and T-depleted and T-replaced male rats. Rats that were gonadally intact (n = 33), gonadectomized (GDX; n = 30), or GDX with silastic capsules of T implanted (n = 28) were tested through a battery of affective tasks (horizontal crossing, open field, elevated plus-maze, emergence, holeboard, social interaction, tailflick, pawlick, and defensive burying) and in the inhibitory avoidance task for cognitive performance. An additional 6 rats per group had plasma androgen concentrations measured and were determined to be physiological for intact rats, supraphysiological for T-implanted rats, and near the nadir for GDX rats. Testosterone implants produced analgesia as shown by the increased tailflick latencies of the GDX rats with silastic capsules of T implanted, relative to intact or GDX rats. Testosterone also produced anxiolysis. Intact rats spent more time interacting with a conspecific and less time burying an electrified prod than did the GDX or T-implanted rats. Intact rats or GDX rats with T implants also spent more time on the open arms of the elevated plus-maze than did GDX rats. Testosterone also enhanced cognitive performance in the inhibitory avoidance task. Intact rats had longer crossover latencies in the inhibitory avoidance task relative to GDX rats; GDX rats with T implants had longer crossover latencies relative to GDX or intact rats. Together, these data demonstrate that endogenous T or administration of T produced analgesia and enhanced affect and cognitive performance of adult male rats.
Frye
C A
CA
Department of Psychology, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA. cafrye@cnsunix.albany.edu
Seliga
A M
AM
D000818:Animals; D001143:Arousal / Q000187:drug effects* / Q000502:physiology; D001522:Behavior, Animal / Q000187:drug effects* / Q000502:physiology; D003071:Cognition / Q000187:drug effects* / Q000502:physiology; D005239:Fear / Q000187:drug effects / Q000502:physiology; D008297:Male; D009919:Orchiectomy; D017288:Pain Threshold / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D020318:Rats, Long-Evans; D013739:Testosterone / Q000494:pharmacology* / Q000502:physiology
D013739:Testosterone