Anabolic steroids have long-lasting effects on male social behaviors

Abstract

Anabolic androgenic steroids (AAS) use by adolescents is steadily increasing. Adolescence involves remodeling of steroid-sensitive neural circuits that mediate social behaviors, and previous studies using animal models document effects of AAS on male social behaviors. The present experiments tested whether AAS have persistent and more pronounced behavioral consequences when drug exposure occurs during adolescence as compared to exposure in adulthood. Male Syrian hamsters were injected daily for 14 days with either vehicle or an AAS cocktail containing testosterone cypionate (2 mg/kg), nandrolone decanoate (2 mg/kg), and boldenone undecylenate (1 mg/kg), either during adolescence (27-41 days of age) or adulthood (63-77 days of age). As adults, subjects were tested two or four weeks after the last injection for either sexual behavior with a receptive female or male-male agonistic behavior in a resident-intruder test. Compared with vehicle-treated males, AAS-treated males, regardless of age of treatment, displayed fewer long intromissions and a significant increase in latency to the first long intromission, indicative of reduced potential to reach sexual satiety. Increased aggression was observed in males exposed to AAS compared with males treated with vehicle, independently of age of AAS treatment. However, unlike hamsters exposed to AAS in adulthood, hamsters exposed to AAS during adolescence did not display any submissive or risk-assessment behaviors up to 4 weeks after discontinuation of AAS treatment. Thus, AAS have long-lasting effects on male sexual and agonistic behaviors, with AAS exposure during adolescence resulting in a more pronounced reduction in submissive behavior compared to AAS exposure in adulthood.

Figure 1. AAS exposure reduces the potential to reach satiety

Three-way (larger graphs) and two-way (smaller insets) ANOVAs determined that AAS exposure during adolescence or adulthood significantly decreases the number of long intromissions (A) and increases long intromission latency (B) independent of time of behavioral testing and age at treatment. Asterisks in the insets indicate a significant difference (p < 0.05) between AAS- and vehicle-treated groups within age of exposure.

Figure 2. AAS treatment results in persistent elevations in the number of attacks and bites

A three-way ANOVA revealed a main effect of treatment and age of exposure on the expression of both (A) attacks and (B) bites. No effects of time of testing or significant interactions were found. A 2-way ANOVA comparing age of treatment and treatment determined that AAS exposure (insets) increased attacks and bites independently of age of treatment. Asterisk and number sign (#) in the insets indicate significant (p < 0.05) main effects of treatment and age of treatment, respectively. Main effect of age of treatment reflects the expected higher levels of aggressive behavior of males tested at younger ages (see behavior of males treated with vehicle during adolescence or adulthood).

Figure 3. AAS results in a persistent increase in attack duration and overall aggression

Three-way ANOVA revealed a main effect of treatment and age of exposure on (A) attack duration and (B) the composite aggression score. No effects of time of testing or significant interactions were found. Two-way ANOVA comparing age of exposure and treatment determined that AAS exposure increased attack duration and overall aggression (insets). Asterisk and number sign (#) in the insets indicate significant (p < 0.05) main effects of treatment and age of treatment, respectively. Main effect of age of treatment reflects the expected higher levels of aggressive behavior of males tested at younger ages (see behavior of males treated with vehicle during adolescence or in adulthood).

Figure 4. AAS results in persistent increases in flank marking behavior

Three-way ANOVA showed that flank marking behavior was significantly increased by AAS treatment and revealed an interaction between age of exposure and time of testing post treatment. The interaction reflects age-related changes in flank marking behavior, which can be seen in the vehicle-treated groups..