下丘脑局部损毁对大鼠双侧催产素神经元爆发放电的影响

EFFECT OF SELECTIVE LESIONS IN HYPOTHALAMUS ON BILATERAL SYNCHRONIZED BURSTS OF RAT OXYTOCIN NEURONS

为探究授乳大鼠双侧下丘脑巨细胞催产素神经元同步化射乳反射爆发放电的中枢所在， 我们采用双微电极细胞外记录技术， 观察了选择性脑切割损毁后的大鼠双侧视上核内催产素神经元在仔鼠吸吮刺激下射乳反射爆发放电。结果显示： 在腹侧被盖以上横向切断单侧中脑中部， 不能阻断双侧催产素神经元的同步化爆发放电； 但是单侧下丘脑中间内侧部横切则可阻断这种同步化爆发放电。这些结果表明： 中脑中部至下丘脑中部这一脑区在双侧视上核内催产素神经元的同步化爆发放电中发挥着关键性作用。

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.