DISCHARGE PATTERNS OF MOTONEURONS

这项研究的长期目标是确定 介导初级传入去极化的中间神经元 (PAD)猫脊髓的肌肉和皮肤传入纤维 索，并更精确地定义反射路径， 他们属于，以及调节的超脊椎影响， 他们的活动。 实验将在麻醉， 去大脑和去大脑/脊髓猫，自发或 瘫痪并进行人工呼吸 特别注意 将给予：a），细胞内PAD的表征 由分段输入和下行输入产生的模式 生理上鉴定的单一Ia、Ib和II类传入神经 与内侧腓肠肌（MG）保持连续的纤维 肌肉，无论是在正常的准备和1周到9个月之间 切断MG神经后，B），以确定是否 皮肤纤维的兴奋和抑制作用 在Ib纤维的PAD上， 下行影响 C.描述可能的 直流电位变化与钾瞬变的相关性 刺激产生的皮肤纤维PAD 脊髓上核，以及阻断GABA能的药物的作用 以及PAD上的肾上腺素能传输。 （二）调查 单个中间核中间神经元对 运动神经元突触电位和背根电位 由组1和皮肤齐射引起，e），以公开 可能参与抑制作用的递质 运动神经元上的中间核中间神经元和f），分析 单个la纤维诱发的单突触EPSP的波动 在脊髓MG运动神经元中， 协同和拮抗肌肉，并在电 刺激运动神经产生la-EPSP的抑制。

The long term goals of this research are to identify the interneurons which mediate the primary afferent depolarization (PAD) of muscle and cutaneous afferent fibers in the cat spinal cord, and to define more precisely the reflex pathways to which they belong, as well as the supraspinal influences which modulate their activity. Experiments will be performed in anesthetized, decerebrated and decerebrated/spinal cats, either spontaneously or paralyzed and under artificial respiration. Particular attention will be given to: a), characterization of the intracellular PAD patterns produced by segmental and descending inputs on physiologically identified single group Ia, Ib and II afferent fibers left in continuity with the medial gastrocnemius (MG) muscle, both in normal preparations and between 1 week and 9 months after sectioning and resuturing the MG nerve. b), to determine if the excitatory and inhibitory actions that cutaneous fibers have on the PAD of Ib fibers are modulated by supraspinal tonic descending influences. c), to characterize the possible correlation of the DC potential changes and potassium transients with the PAD of cutaneous fibers produced by stimulation of supraspinal nuclei, and the effects of drugs blocking GABAergic and serotonergic transmission on the PAD. d), to investigate the actions of single intermediate nucleus interneurons on the motoneuron synaptic potentials and on dorsal root potentials elicited by group 1 and by cutaneous volleys, e), to disclose the transmitters possibly involved in the inhibitory actions of intermediate nucleus interneurons on motoneurons and f), analyze the fluctuations of monosynaptic EPSPs elicited by single la fibers in spinal MG motoneurons during various amounts of stretch of synergistic and antagonistic muscles and during electrical stimulation of motor nerves producing depression of la-EPSPs.