[Effect of selective lesions in hypothalamus on bilateral synchronized bursts of rat oxytocin neurons].

In order to clarify the location of the center for synchronized milk-ejection bursts of magnocellular oxytocin neurons in the hypothalamus, the bursts of these neurons were recorded extracellularly in lactating rats with selectively-cutting lesions of the middle brain or hypothalamus. Results showed that unilateral transection of the middle midbrain above the ventral tegmentum did not block the synchronized bursts on both sides; however, the synchronized bursts disappeared after unilateral transection through the middle of the medial hypothalamus. These results suggest that the area from the middle part of the midbrain to that of the hypothalamus does play a crucial role in the synchronized milk-ejection burst.