Mitsushima D, Yokawa T, Nishihara M, Takahashi M
Department of Veterinary Physiology, University of Tokyo, Japan.
Physiol Behav. 1994 Nov;56(5):891-9. doi: 10.1016/0031-9384(94)90320-4.
To alter neural networks in a restricted area of the brain, we previously developed the hydro-polymer gel (PG) implantation technique. In this study, we found that bilateral or unilateral injection of PG (1.6 microliters) into the ventromedial nucleus of the hypothalamus (VMH), contrary to injections into the preoptic area (POA) or posterior hypothalamic area (PHA), severely attenuated circadian changes of locomotor activity in blinded female rats. In addition, PG injection into the VMH also suppressed circadian changes in serum melatonin levels and induced persistent estrus. The effect of PG injection into the VMH on free-running rhythm was blocked by a complete cut around the VMH or a dorsal cut of the VMH but not by anterior or posterior cuts of the VMH. These results suggest that PG injection into the VMH induces some form of neural output via a dorsal route of the VMH that affects the generation of circadian activity rhythm.
为了在大脑的特定区域改变神经网络，我们之前开发了水凝胶聚合物（PG）植入技术。在本研究中，我们发现，与向视前区（POA）或下丘脑后区（PHA）注射相比，向下丘脑腹内侧核（VMH）双侧或单侧注射PG（1.6微升）会严重减弱失明雌性大鼠运动活动的昼夜节律变化。此外，向VMH注射PG还会抑制血清褪黑素水平的昼夜节律变化，并诱导持续发情。向VMH注射PG对自由运行节律的影响可通过VMH周围的完全切断或VMH的背侧切断来阻断，但不能通过VMH的前侧或后侧切断来阻断。这些结果表明，向VMH注射PG会通过VMH的背侧途径诱导某种形式的神经输出，从而影响昼夜活动节律的产生。
