Suckling decreases dopamine turnover in both medial and lateral aspects of the median eminence in the rat.

The effect of suckling on dopamine (DA) turnover was studied in the medial and lateral aspects of the median eminence. In 10-day postpartum lactating rats suckling decreased DA turnover 2.2-fold in the medial and 2.1-fold in the lateral median eminence. Norepinephrine turnover did not differ in suckled and non-suckled rats. These results are consistent with the hypothesis that decreased DA release is a component of the neuroendocrine reflex mediating suckling-induced prolactin release. The results further indicate that dopaminergic neurons distributing to both medial and lateral aspects of the median eminence are involved in the suckling response.