Amine neurotransmitter levels in male and female rats through developmental periods.

Monoamines (MA) such as dopamine (DA), norepinephrine (NE), and 5-hydroxytryptamine (5-HT) are now generally regarded as widely distributed and essential endogenous mediators contributing to the integration of reproductive physiology. MA measured in the hypothalamus tissue of male and female rats aged 1 to 90 days showed its own characteristic development pattern. Significant differences were observed at 5, 15, and 90 days of age in NE mean levels and at all ages except for 3 days of age in 5-HT mean levels. In contrast, no sex differences were seen in DA mean levels.