METABOLITE EFFECTS OF GROUP III AND IV MUSCLE AFFERENTS

描述(改编自申请人的摘要)： 本申请中提出的实验是为了确定动态 运动对III、IV组肌肉放电的不同影响 传入器。去大脑未麻醉的猫将通过以下方法诱导运动 对中脑运动区的电和化学刺激。这个 不同运动水平和脑缺血对大鼠脑电活动的影响 第三组和第四组肌肉传入将被确定。我们将特别注意 注意传入对运动后循环闭塞的反应 “纯粹的”代谢性反射刺激。我们还将注意到 环氧合酶代谢物和缓激肽在刺激这些传入神经中的作用 动感运动。最后，拟议的实验将检验 肌肉疲劳对III、IV组传入运动反应的影响。 这些细纤维传入被假设为负责 疲劳性肌肉收缩时α运动神经元的反射抑制 在人类身上。自主神经和呼吸系统对动态运动的反应良好 并包括交感神经放电的增加，影响 血管系统、心率、收缩能力、呼吸频率和潮气量。 导致这些增加的神经机制存在争议。这个 本申请中提出的实验将确定机械和 在运动过程中对这些传入的代谢刺激。

DESCRIPTION (Adapted from the applicant's abstract):The overall aim of the experiments proposed in this application is to determine whether dynamic exercise differentially affects the discharge of group III and IV muscle afferents. Exercise will be induced in decerebrate unanesthetized cats by electrical and chemical stimulation of the mesencephalic locomotor region. The effects of various levels of exercise and ischemia on the discharge of the group III and IV muscle afferents will be determined. Particular attention will be paid to afferent's responses to post-exercise circulatory occlusion, a "pure" metaboreflex stimulus. Attention will also be paid to the role played by cyclooxygenase metabolites and bradykinin in stimulating these afferents during dynamic exercise. Finally, the proposed experiments will examine the effect of muscular fatigue on the responses of group III and IV afferents to exercise. These thin fiber afferents have been hypothesized to be responsible for the reflex inhibition of alpha motoneurons during fatiguing muscular contractions in humans. The autonomic and ventilatory response to dynamic exercise are well established and include increases in sympathetic discharge influencing the vasculature, heart rate, contractility, breathing frequency and tidal volume. The neural mechanisms causing these increases are controversial. The experiments proposed in this application will determine the mechanical and metabolic stimuli to these afferents during exercise.