BRAINSTEM NEURON ACTIVITY IN A MODEL OF OROFACIAL PAIN

尽管许多研究表明，中缝核 马格努斯(Rm)是下行通道中的重要继电器 调制伤害性信息传递，人们对此知之甚少 服务于此的RM神经元的细胞解剖学和生理学 重要的功能。因此，有人提议进行实验，以 细胞形态和免疫细胞化学的测定 生理学特征的RM细胞。首先，确定RM如何 神经元在伤害性感受时被激活，即细胞内 在反射颌骨过程中将测定RM神经元的反应 由牙髓电击或有害的嘴唇加热引起的张开。 神经元激活与潜在突触后的模式 电势将与感官刺激和 马达反应的时间和强度。第二，因为 已知刺激中脑导水管周围灰质区域(PAG) 部分通过激活RM神经元抑制伤害性反射， Rm神经元的活动将被记录在抑制 由电刺激PAG产生的反射性张开颌骨。 牙髓休克和热刺激对RM神经元的激活作用 将与肌电幅度的变化相关 PAG的反应及其抑制作用的时程 对张开下巴的刺激。第三，形态结构。 生理特征的RM神经元将由以下因素决定 细胞内HRP标记。形态与轴突 单个RM神经元的投射是非常不同的。 细胞内标记将允许解剖学和 单细胞的生理学，使得确定 Rm神经元的形态特征对应于 巨噬细胞内离散神经元群体的功能差异。 第四，生理学的神经化学含量 具有特征性的RM神经元将被确定。一批 不同的神经递质候选者，包括5-羟色胺， P物质和生长抑素已定位于细胞内。 Rm。为了确定个体的发送器内容， 生理学特征的RM神经元，细胞内标记 将结合免疫细胞化学染色。这种方法 将决定不同的RM神经元 在电生理学方面，它们的发射器也不同 内容。第五，传入纤维的神经递质含量 这种联系将被确定为RM神经元。RM神经元接收 来自接触RM神经元的传入纤维的输入将是 下定决心。RM神经元从含有以下物质的传入神经元接受输入 5-羟色胺、神经降压素和生长抑素。免疫细胞化学 将与RM神经元的细胞内标记相结合，以 确定传入神经中含有哪些神经递质 接触单个的、具有生理特征的RM神经元。

Although many studies demonstrate that the nucleus raphe magnus (RM) is an important relay in descending pathways that modulate nociceptive transmission, little is known about the cellular anatomy and physiology of RM neurons that serve this important function. Experiments are therefore proposed that will determine the morphology and immunocytochemistry of physiologically characterized RM cells. First, to identify how RM neurons are activated during nociception, the intracellular responses of RM neurons will be determined during reflex jaw opening evoked by tooth-pulp shock or by noxious lip heating. Neuron activation and the pattern of underlying postsynaptic potentials will be related to the sensory stimulus and to the timing and intensity of the motor response. Second, since stimulation of the periaqueductal gray region (PAG) is known to suppress nociceptive reflexes in part by activating RM neurons, the activity of RM neurons will be recorded during inhibition of reflex jaw opening produced by electrical stimulation of the PAG. RM neuron activation by tooth pulp shock and thermal stimulation will be correlated with the change in amplitude of the EMG response and the time course of the inhibitory effects of PAG stimulation on jaw opening. Third, the morphology of physiologically characterized RM neurons will be determined by labeling with intracellular HRP. The morphology and axonal projections of individual RM neurons are very heterogeneous. Intracellular labeling will allow correlation of anatomy and physiology of single cells, making it possible to determine whether the morphological features of RM neurons correspond to functional differences in discrete neuronal populations within RM. Fourth, the neurochemical content of physiologically characterized RM neurons will be determined. A number of different neurotransmitter candidates, including serotonin, substance P and somatostatin have been localized to cell bodies in RM. In order to determine the transmitter content of individual, physiologically characterized RM neurons, intracellular labeling will be combined with immunocytochemical staining. This method will determine whether RM neurons that differ electrophysiologically also differ with regard to their transmitter content. Fifth, the neurotransmitter content of afferent fibers that contact RM neurons will be determined. RM neurons receive input from afferent fibers that contact RM neurons will be determined. RM neurons receive input from afferents containing serotonin, neurotensin and somatostatin. Immunocytochemistry will be combined with intracellular labeling of RM neurons to determine which neurotransmitters are contained in afferents that contact individual, physiologically characterized RM neurons.