Pubertal testosterone programs context-appropriate agonistic behavior and associated neural activation patterns in male Syrian hamsters.

Pubertal testosterone programs the level of aggressive behavior displayed by male Syrian hamsters during resident-intruder interactions. To further explore the pubertal programming of adult male agonistic behaviors, the current study investigated the formation, stability, and maintenance of dominant-subordinate relationships in males that either did (T@P) or did not (NoT@P) experience testicular hormones during adolescent development. NoT@P males were gonadectomized prepubertally and T@P males were gonadectomized in adulthood. Four weeks after gonadectomy, all males received testosterone-replacement. Two weeks later, two males of the same hormonal history were given a 60 min introductory trial in a neutral arena, followed immediately and again 24h later by three 5-min trials. During the introductory trial, each male was deemed dominant, subordinate, or no-status. Brains were collected 1h after the last trial and sections were stained for Fos-immunoreactivity. Dominant T@P males flank marked more frequently than subordinate and no-status T@P males; this difference was not found in NoT@P males. NoT@P males showed an increase in the number of offensive postures the day after the first series of tests, whereas T@P males did not. Dominant T@P males had significantly more Fos expression than no-status T@P males in anterior cingulate cortex; this relationship was not observed in NoT@P males. Additionally, dominant T@P males had higher Fos expression than dominant NoT@P males in lateral septum. Thus, pubertal testosterone does not organize the formation or stability of male-male relationships, but does program the behavioral strategies used to maintain these relationships over time and the neural correlates of status.