The testosterone metabolite and neurosteroid 3alpha-androstanediol may mediate the effects of testosterone on conditioned place preference

Testosterone rapidly reduces anxiety in male house mice (Mus musculus)

Eight experiments supported the hypotheses that reflexive testosterone release by male mice during sexual encounters reduces male anxiety (operationally defined in terms of behavior on an elevated plus-maze) and that this anxiolysis is mediated by the conversion of testosterone to neurosteroids that interact with GABA(A) receptors. In Experiment 1, a 10-min exposure to opposite-sex conspecifics significantly reduced both male and female anxiety 20 min later (as indexed by increased open-arm time on an elevated plus-maze) compared to control mice not receiving this exposure. In contrast, locomotor activity (as indexed by enclosed-arm entries on the elevated plus-maze) was not significantly affected. The remaining experiments examined only male behavior. In Experiment 2, exposure to female urine alone was anxiolytic while locomotor activity was not significantly affected. Thus, urinary pheromones of female mice likely initiated the events leading to the male anxiolysis. In phase 1 of Experiment 3, sc injections of 500 microg of testosterone significantly reduced anxiety 30 min later while locomotor activity was not significantly affected. Thus, testosterone elevations were associated with reduced male anxiety and the time course consistent with a nongenomic, or very rapid genomic, mechanism of testosterone action. In phase 2 of Experiment 3, the anxiolytic effect of testosterone was dose dependent with a 250 microg sc injection required. Thus, testosterone levels likely must be well above baseline levels (i.e., in the range induced by pulsatile release) in order to induce anxiolysis. In Experiment 4, a high dosage of 5alpha-dihydrotestosterone was more anxiolytic than a high dosage of estradiol benzoate, suggesting that testosterone action may require 5alpha-reduction. In Experiments 5 and 6, 3alpha,5alpha-reduced neurosteroid metabolites of testosterone (androsterone and 3alpha-androstandione) were both anxiolytic at a lower dosage (100 microg/sc injection) than testosterone, supporting the notion that testosterone is converted into neurosteroid metabolites for anxiolytic activity. Experiments 7 and 8 found that either picrotoxin or bicucculine, noncompetitive and competitive antagonists of the GABA(A) receptor, respectively, blocked the anxiolytic effects of testosterone. However, conclusions from these 2 experiments must be tempered by the reduction in locomotor activity that was also seen. The possible brain locations of testosterone action as well as the possible adaptive significance of this anxiolytic response are discussed.

Anabolic steroid abuse and dependence

Anabolic-androgenic steroids (AAS) are mainly used to treat androgen deficiency syndromes and, more recently, catabolic states such as AIDS-associated wasting. There is no evidence in the reviewed literature that AAS abuse or dependence develops from the therapeutic use of AAS. Conversely, 165 instances of AAS dependence have been reported among weightlifters and bodybuilders who, as part of their weight training regimens, chronically administered supraphysiologic doses, often including combinations of injected and oral AAS as well as other drugs of abuse. A new model is proposed in which both the "myoactive" and psychoactive effects of AAS contribute to the development of AAS dependence. The adverse consequences of AAS are reviewed, as well as their assessment by means of a history and physical, mental status examination, and laboratory testing. When patients with AAS use disorders are compared with patients with other substance use disorders, both similarities and differences become apparent and have implications for treatment.

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.

Inhibiting progesterone metabolism in the hippocampus of rats in behavioral estrus decreases anxiolytic behaviors and enhances exploratory and antinociceptive behaviors

Blocking progesterone's metabolism to 5 alpha-pregnan-3 alpha-ol-20-one (3 alpha,5 alpha-THP) with finasteride, a 5 alpha-reductase inhibitor, and effects on anxiolytic, exploratory, and antinociceptive behaviors of rats in behavioral estrus were examined. Rats in behavioral estrus received finasteride systemically (SC), to the hippocampus, or to control implant sites, the nucleus accumbens (NA) or ventral tegmental area (VTA), and were tested in horizontal crossing, open-field, elevated plus-maze, emergence, holeboard, social interaction, tailflick, pawlick, and defensive freezing tasks. Finasteride, SC or intrahippocampally, reduced 3 alpha,5 alpha-THP in the hippocampus relative to vehicle implants or finasteride to the NA or VTA. Systemic or intrahippocampal finasteride decreased central entries in the open field and open-arm time on the elevated plus-maze and increased freezing in response to shock relative to vehicle. Finasteride to the hippocampus decreased emergence latencies and increased social interaction, pawlick, and tailflick latencies relative to all other groups. Finasteride to the hippocampus of rats in behavioral estrous decreased anxiolysis and enhanced exploration and analgesia. In summary, these data demonstrate that decreases in anxiolytic behavior of behavioral estrous rats can be produced by reductions in 3 alpha,5 alpha-THP in the hippocampus, which suggest that elevations in 3 alpha,5 alpha-THP in the hippocampus may give rise to anxiolysis seen during behavioral estrus.