Ota M
Jpn J Physiol. 1975;25(3):303-16.
The effect of electrical stimulation of the mesencephalic reticular formation (MRF) on the pyramidal tract (PT) response to cortical stimulation in adult rats was examined with and without alpha adrenergic blocking agents and other chemicals, applied intravenously, intraperitoneally or topically to the exposed cerebral cortex. 1. By MRF stimulation, the initial component of the PT response (D wave) was not significantly altered but the later component (I waves) was initially facilitated and subsequently inhibited. 2. Intravenously applied alpha adrenergic blocking agents, phentolamine and phenoxybenzamine consistently blocked reticulo-cortical inhibition. The reticulo-cortical facilitation was significantly reduced by phentolamine but the effect of phenoxybenazmine was not consistent on this mechanism. Neither the PT response nor the effect of MRF stimulation on it was affected by propranolol or atropine. 3. Phentolamine or phenoxybenazmine, topically applied to the cortical surface, blocked the reticulo-cortical inhibition but did not alter the reticulo-cortical facilitation. 4. A monoamine oxidase inhibitor, iproniazid (i.p.), significantly potentiated the reticulo-cortical inhibition but the effect on the reticulocortical facilitation was not statistically significant. 5. These results suggest that the reticular inhibitory effect on the motor cortical activity is mediated through an alpha adrenergic mechanism and the receptor site is distributed in the cerebral cortex.
在成年大鼠中，在静脉内、腹腔内或局部应用于暴露的大脑皮层的情况下，使用或不使用α肾上腺素能阻断剂及其他化学物质，研究了中脑网状结构（MRF）电刺激对锥体束（PT）对皮层刺激反应的影响。1. 通过MRF刺激，PT反应的初始成分（D波）没有显著改变，但后期成分（I波）最初得到促进，随后受到抑制。2. 静脉内应用的α肾上腺素能阻断剂酚妥拉明和酚苄明持续阻断网状-皮层抑制。酚妥拉明显著降低了网状-皮层促进作用，但酚苄明对该机制的作用并不一致。普萘洛尔或阿托品对PT反应及其对MRF刺激的影响均无作用。3. 将酚妥拉明或酚苄明局部应用于皮层表面，可阻断网状-皮层抑制，但不改变网状-皮层促进作用。4. 一种单胺氧化酶抑制剂异烟酰异丙肼（腹腔内注射）显著增强了网状-皮层抑制，但对网状-皮层促进作用的影响无统计学意义。5. 这些结果表明，对运动皮层活动的网状抑制作用是通过α肾上腺素能机制介导的，且受体位点分布在大脑皮层。
