Intrinsic control of cerobro-vascular tone-role of central nor-advenergic system

我们研究了中央背侧和中央去肾上腺素能系统（蓝斑复合体，LC，髓网状结构，MRF）和胆碱感受脑桥区（CPA）在控制脑血管舒张性张力中的作用。实验采用氯氯蔗糖麻醉的30只猫，分别伴有或不伴有高岭土性脑积水。[1]在LC或MRF中微量注射谷氨酸或碳水化合物可引起ICP降低，并伴有血压轻微升高。另一方面，微注射苯酚或乙酰胆碱在CPA中产生类似icp的“平台波”变化。[II] LC神经元的强直性放电在平台波开始前10 ~ 30秒逐渐被抑制，在平台期几乎完全沉默。强直性mrf神经元放电在高原波开始前30秒逐渐被抑制，并在高原期急剧被抑制。在ICP下降前10 ~ 30秒开始恢复。另一方面，cpa神经元的放电频率随平台波呈阶段性增加。[III]电生理研究表明，CPA神经元抑制构成中枢去肾上腺素能系统的LC和mrf神经元。CPA神经元的激活会抑制中枢去肾上腺素能系统的活动。CBV的增加是对脑血管扩张的反应。这些结果表明，CPA、LC和MRF内的活性有助于ICP的变化，并且是高岭土诱导脑积水等情况下发生的平台波的内源性神经元来源。

We have investigated the role of the central dorsal and rentral noradrenergic systems (Locus Coeruleus Complex, LC, Medullary Reticular Formation, MRF) and the cholinoceptive pontine area (CPA) in control of cerebral vasomotor tone. The experiments were performed on 30 chloralose-anesthetized cats with or without Kaolin induced hydrocephalus.[I] Microinjection of glutamate or carbochol into the LC or the MRF induced decrease of ICP in association with a slight rise of BP.On the other hand microinjection of carbachol or Ach into the CPA produced "plateau wave" like ICP-variations.[II] Tonic discharges of the LC neuron were gradually suppressed at 10 to 30 sec. prior to the onset of plateau waves, almost completely silenced during the plateau phase. Tonic MRF-neuron discharges were gradually suppressed about 30 sec. before onset o fplateau wave like ICP-variations and sharply suppressed during the plateau phase. Recovery began 10 to 30 sec. before the ICP decrease. On the other hand, the firing rate of the CPA-neuron was increased in phase with the plateau waves.[III] Electrophysiological studies show that the CPA neurons suppress both the LC and MRF-neurons which make up the central noradrenergic system. Activation of the CPA neurons should suppress activity in the central noradrenergic system. The increase in CBV then occurrs in response to dilatation of cerebral vessels.These results suggest that activity within the CPA, LC and MRF contributes to ICP changes and is the endogenous neuronal origin of plateau waves occurring in some conditions such as Kaolin induced hydrocephalus.