Function of the Trigeminal Ganglion-Cochlear Nucleus

描述：(改编自申请者摘要)：我们已证明 三叉神经节向听性脑干和耳蜗发投射 脉管系统。脑干末端为颗粒细胞和巨细胞细胞。 耳蜗腹核区和橄榄耳蜗区 上橄榄复合体中的神经元。神经支配的耳蜗部 调节耳蜗内的血液流动。然而，脑干的功能 投影是未知的。初步调查结果表明，对VCN的预测 令人兴奋。颗粒细胞的轴突(平行纤维)投射到背部 耳蜗核(DCN)。因此，三叉神经支配引起的兴奋 可影响耳蜗核(CN)的大部分输出神经元。一系列 旨在阐明这一新的CN部分的功能 投射并定义其神经递质： 观察时，三叉神经节将受到电刺激。 CN中单个单元的响应。候选神经递质，物质 P和一氧化氮，将用免疫细胞化学和 神经药理学。三叉神经节在三叉神经节的发生和发展中的作用 将探索耳鸣的调制：多达三分之二的耳鸣 患者可以通过咬合下巴或触摸耳鸣来调节耳鸣 面部皮肤，三叉神经节支配的区域。其他人可以 将耳鸣的发生归因于头部和颈部的躯体侮辱 (“躯体耳鸣”)。假设增加的自发频率是一种 耳鸣的表现及其通过躯体感觉传入中枢的调节 可能在耳鸣的发生和调节中起作用。假说 通过电刺激三叉神经节来测试WiFi 以CN的单个单位记录自发活动。识别 在这一途径中使用的神经递质可以为以后的药物奠定基础 治疗。

DESCRIPTION: (Adapted from applicant's abstract): We have demonstrated that the trigeminal ganglion sends a projection to the auditory brain stem and to the cochlear vasculature. The terminations in the brainstem end in granular and magnocellular regions of the ventral cochlear nucleus (VCN) and at the locations of olivocochlear neurons in the superior olivary complex. The cochlear portion of the innervation modulates blood flow within the cochlea. However, the function of the brainstem projection is unknown. Preliminary findings suggest that the projection to the VCN is excitatory. The axons of granule' cells (parallel fibers) project to the dorsal cochlear nucleus (DCN). Therefore, excitation by the trigeminal innervation could affect most of the output neurons of the cochlear nucleus (CN). A series of studies is designed to elucidate the function of the CN portion of this new projection and define its neurotransmitters: The trigeminal ganglion will be electrically stimulated while observing the responses of single units in the CN. The candidate neurotransmitters, Substance P and Nitric Oxide, will be evaluated using immunocytochemistry and neuropharmacology. A role for the trigeminal ganglion in the generation and modulation of tinnitus will be explored: As many as two thirds of tinnitus patients are able modulate their tinnitus by clenching the jaw or touching the skin on the face, areas innervated by the trigeminal ganglion. Others can attribute the onset of tinnitus to a somatic insult in the head and neck region ("somatic tinnitus"). On the assumption that increased spontaneous rate is a manifestation of tinnitus, its modulation by somatosensory input to the CN could play a role in the generation and modulation of tinnitus. The hypothesis wifi be tested by electrically stimulating the trigeminal ganglion while recording spontaneous activity in single units of the CN. Identifying the neurotransmitter used in this pathway could then set the stage for later drug treatments.