Correlations between catecholamine levels and sexual behavior in male zebra finches.

In zebra finches, the combined actions of estrogens and androgens activate male courtship, including singing, and also strongly modulate norepinephrine (NE) levels and turnover in brain areas known to be involved in controlling courtship behavior. To determine whether changes in NE levels mediate changes in courtship, we administered DSP-4 to males and measured its effects on monoamine levels and reproductive behavior. DSP-4 treatment did not affect serotonin (5-HT), had small, variable effects on dopamine (DA), and caused moderate, nonsignificant reductions in NE. However, in DSP-4-treated males, NE levels in specific vocal-control nuclei showed high positive correlations with courtship singing. There were no significant correlations between NE levels in hypothalamic nuclei and any behavior or DA or 5-HT levels in any nuclei and any behavior. DSP-4-treated males took longer to begin singing and performed fewer song bouts and courtship displays, but their songs could not be differentiated from those of control males. This suggests that their behavioral deficits resulted from deficits in attention rather than an inability to sing.