BRAIN STEM MECHANISMS CONTROLLING JAW MOVEMENT

这项提案的具体目标是阐明脑干 神经生理和神经药理机制控制 豚鼠类似咀嚼的节律性下颌运动（RJMs） 猪 我们建议表征控制的药理学机制 开颌运动神经元和前运动神经元兴奋性 由皮层（或锥体束）的电刺激引起的RJM， 并且在通过多巴胺激动剂的全身给药引起的RJM期间， 阿扑吗啡（APO）。 该项目分为三个部分。 第一部分和 两个将集中于从二腹肌运动神经元的细胞外记录 (DIG)或前运动神经元，分别在皮质诱导的RJM 同时通过微量移液器将小的 量的推定的神经递质（NT）激动剂和拮抗剂。 最后，第三部分将研究神经生理学和 控制这些相同细胞群的神经药理学机制 在APO给药诱导的RJM期间。 长期的目标是了解这两种机制的基础上， 中枢神经系统控制正常的有节奏的下颌运动， 在进食和饮水等活动期间，以及异常， 不自主的有节奏的下颌运动，发生在诸如迟发性 运动障碍和磨牙症。 迟发性运动障碍是一种 以口面部不受控制的有节奏的下颌运动为特征 长期服用精神抑制药物导致的结构。 磨牙症，即睡觉时磨牙或咬紧牙齿， 不受控制的下颌运动行为，往往导致肌面 疼痛功能障碍综合征 这些产生的病因 异常的下颌运动，虽然bruxixm被认为是未知的， 与压力有关，迟发性运动障碍与多巴胺的破坏有关， 基底神经节的活动。 所提出的实验的结果， 豚鼠将提供关于神经生理学的见解， 神经药理学机制的产生不自主的 人类有节奏的下颌运动。

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.