Investigating the role of testicular hormones at puberty on motivated behaviors and mesolimbic dopamine circuits

Adolescence is associated with the maturation of reward-related processing and motivated behaviors. While puberty coincides with adolescence, the causal relationship between puberty and the maturation of mesolimbic dopamine circuits remains poorly understood. Here, we used a closed-economy progressive ratio task to assess the effects of pre- vs. postpubertal gonadectomy and D2R antagonism on motivated responding for food. We observed no difference in daily pellet consumption under no-cost conditions but found that P25 sham males tested at ~P70 exhibited higher max breakpoints on saline compared to P25 GDX males and P90 sham males. Furthermore, P25 sham males were the only group in which haloperidol significantly reduced max breakpoints. These data indicate that prepubertal GDX blunts a young adult peak in operant responding that is sensitive to D2R antagonism. Ongoing experiments will determine whether these behavioral differences relate to changes in dopamine content and/or signaling dynamics within the nucleus accumbens and dorsomedial striatum.