BRAIN STEM MECHANISMS CONTROLLING JAW MOVEMENT

这项提议的具体目的是阐明脑干 神经生理学和神经药理学机制控制 豚鼠类似咀嚼的节律性下巴运动(RJM) 猪。我们建议对其药理机制进行表征。 张口肌(二腹肌)运动神经元和前运动神经元兴奋性 由电刺激皮质(或锥体束)引起的RJMS， 在全身注射多巴胺激动剂引起的RJMS期间， 阿朴吗啡(APO)。该项目分为三个部分。第一部分和 两个将专注于从二腹肌运动神经元进行细胞外记录 (DIG)或前运动神经元分别在皮质诱导的RJMS中 同时通过微吸管施加到细胞，小的 推测的神经递质(NT)激动剂和拮抗剂的数量。 最后，第三部分将研究神经生理学和 控制这些细胞群体的神经药理学机制 在APO诱导的RJMS期间。 长期目标是理解这两个基础的机制 中枢神经系统对发生的正常有节奏的下颌运动的控制 在进食和饮水等活动中，以及异常情况下， 在迟缓等障碍中出现的不自主的有节奏的下巴运动 运动障碍和磨牙症。迟发性运动障碍是一种运动障碍 以口腔面部不受控制的有节奏的下巴运动为特征 由于长期服用抗精神病药物而产生的结构。 磨牙症，即睡眠中磨牙或咬合，是另一种 不受控制的下巴运动行为，通常会导致肌肉面部 疼痛功能障碍综合征。这些病原学的产生 不明原因的异常下巴运动，尽管布鲁西姆被认为是 与压力有关，迟发性运动障碍与多巴胺中断有关 基底节的活动。建议中的实验结果 豚鼠将提供对神经生理学和 产生不自主神经的神经药理学机制 人类的下颌有节奏的运动。

The specific aims of this proposal are to elucidate the brain stem neurophysiological and neuropharmacological mechanisms controlling rhythmical jaw movements (RJMs), resembling mastication, in the guinea pig. We propose to characterize the pharmacological mechanisms controlling jaw opener (digastric) motoneuron and premotoneuron excitability during RJMs elicited by electrical stimulation of the cortex (or pyramidal tract), and during RJMs elicited by systemic administration of a dopamine agonist, apomorphine (APO). The project is divided into three parts. Parts one and two will focus on recording extracellularly from digastric motoneurons (DIG) or pre-motoneurons, respectively, during cortically induced RJMs while simultaneously applying to the cell, through micropipettes, small quantities of putative neurotransmitter (NT) agonists and antagonists. Finally, part three will investigate the neurophysiological and neuropharmacological mechanisms controlling these same cell populations during RJMs induced by APO administration. The long-term goal is to understand both the mechanisms underlying the central nervous system control of normal rhythmic jaw movements that occur during activities such as feeding and drinking, as well as the abnormal, involuntary rhythmic jaw movements occurring in disorders such as tardive dyskinesia and bruxism. Tardive dyskinesia is a movement disorder characterized by uncontrolled rhythmic jaw movements of oral-facial structures that result from long term administration of neuroleptic drugs. Bruxism, the grinding or clenching of teeth in sleep, is another uncontrolled jaw movement behavior that often leads to the myofacial pain-dysfunction syndrome. The etiology of the generation of these abnormal jaw movements in unknown, although brusixm is thought to be related to stress, and tardive dyskinesia to a disruption of dopamine activity in the basal ganglia. The results of the proposed experiments in the guinea pig will provide insights into the neurophysiological and neuropharmacological mechanisms underlying the production of involuntary rhythmic jaw movements in humans.