Davis K D, Dostrovsky J O
Department of Physiology, Faculty of Medicine, University of Toronto, Ont., Canada.
Brain Res. 1988 Jun 28;454(1-2):89-100. doi: 10.1016/0006-8993(88)90806-2.
Previous studies have identified a population of neurons in the cat trigeminal brainstem complex that respond to stimulation of the middle meningeal artery (MMA) and/or superior sagittal sinus (SS). In the present study, neuronal responses to stimulation of the MMA and SS were sought in the thalamus of the cat. Sixty-one neurons excited by electrical stimulation of the MMA and/or SS were located in the ventroposteromedial (VPM) nucleus, and surrounding regions in lateral thalamus. Of these 61 neurons, 23% were excited only by MMA stimulation, 39% only by SS stimulation and 38% by both MMA and SS stimulation. The latencies to activation from MMA and/or SS stimulation suggest the involvement of small, myelinated primary afferent fibers. Most neurons (48/61) responded to electrical stimulation of the MMA or SS with a burst of 2-5 spikes. Mechanical stimulation of the MMA and SS was also an effective stimulus and in some cases evoked a burst response. Of the neurons tested for the existence of orofacial inputs, all were found to have an excitatory receptive field (RF) on the face and usually (22/26 neurons) involved the ophthalmic distribution. Twelve of these neurons were excited by a tap stimulus applied to the face, 6 by pinching (nociceptive specific), 6 by low-threshold mechanical stimuli (LTM), one by both pinch and low-threshold stimuli and one by mechanical stimulation of the cornea. The firing properties, RF and modalities of these thalamic neurons suggest that they may play a role in the appreciation of pain of cerebrovascular origin.
以往的研究已在猫的三叉神经脑干复合体中识别出一群对脑膜中动脉（MMA）和/或上矢状窦（SS）刺激有反应的神经元。在本研究中，我们在猫的丘脑中寻找对MMA和SS刺激的神经元反应。通过对MMA和/或SS进行电刺激而兴奋的61个神经元位于腹后内侧（VPM）核以及丘脑外侧的周围区域。在这61个神经元中，23%仅由MMA刺激兴奋，39%仅由SS刺激兴奋，38%由MMA和SS刺激共同兴奋。来自MMA和/或SS刺激的激活潜伏期表明有小的、有髓鞘的初级传入纤维参与。大多数神经元（48/61）对MMA或SS的电刺激以2 - 5个峰电位的爆发形式做出反应。对MMA和SS的机械刺激也是一种有效的刺激，在某些情况下会诱发爆发反应。在测试是否存在口面部输入的神经元中，发现所有神经元在面部都有一个兴奋性感受野（RF），并且通常（22/26个神经元）涉及眼神经分布。其中12个神经元因对面部施加轻拍刺激而兴奋，6个因捏掐（伤害性特异性）而兴奋，6个因低阈值机械刺激（LTM）而兴奋，1个因捏掐和低阈值刺激两者而兴奋，1个因角膜的机械刺激而兴奋。这些丘脑神经元的放电特性、RF和模式表明它们可能在脑血管源性疼痛的感知中起作用。
