Androgen synthesis inhibition but not gonadectomy reduces persistence during strategy set-shifting and reversal learning in male rats

Abstract

Androgens regulate behavioural flexibility, which is essential to adapt to a changing environment and depends on the medial prefrontal cortex (mPFC). Testosterone (T) administration decreases behavioural flexibility. It is well known that T is produced in the gonads, but T is also produced in the mesocorticolimbic system, which modulates behavioural flexibility. It is unclear how T produced in the brain versus the gonads influences behavioural flexibility. Here, we assess the effects of the androgen synthesis inhibitor abiraterone acetate (ABI) and long-term gonadectomy (GDX) on behavioural flexibility in two paradigms. In Experiment 1, ABI independent of GDX reduced the number of trials to criterion and perseverative errors in a strategy set-shifting task. Similarly, in Experiment 2, ABI but not GDX reduced perseverative errors in a reversal learning task. In subjects from Experiment 1, we also examined tyrosine hydroxylase immunoreactivity (TH-ir), and ABI but not GDX increased TH-ir in the mPFC. Our findings suggest that neurally-produced androgens modulate behavioural flexibility via modification of dopamine signalling in the mesocorticolimbic system. These results suggest novel roles for neurosteroids and possible side effects of ABI treatment for prostate cancer.