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目的 :探讨去甲肾上腺素是否对体感皮层Ⅰ区神经元的自发活动具有调制作用 ,以及这种调制作用是否影响体感皮层对传入信息的感受。方法 :以SD大鼠为实验对象 ,采用多管玻璃微电极刺激记录技术和微电泳注射的方法 ,观察了不同剂量的去甲肾上腺素和刺激隐神经单独作用和共同作用于体感皮层Ⅰ区神经元时自发活动平均放电率的变化。结果 :去甲肾上腺素能易化体感皮层Ⅰ区电泳部位神经元的自发活动 ,使平均放电率增大。当微电泳电流强度从 5nA逐渐加大至 145nA时 ,平均放电率的增加值从 (0 .5 2± 0 .47)脉冲 /s增大到 (2 4.1± 6 .9)脉冲 /s ,表明易化作用逐渐加强 ,且呈剂量———效应正相关依赖关系。去甲肾上腺素对体感皮层Ⅰ区神经元的自发活动有抑制效应 ,但无剂量依赖关系。刺激隐神经的电流强度较弱 ,单纯A类纤维传入时对记录部位神经元的自发活动有抑制作用 ;刺激强度较强 ,A类和C类纤维共同传入时 ,能易化记录部位的自发活动。而且发现 ,去甲肾上腺素与传入信息对体感皮层Ⅰ区神经元自发活动的调制有相互作用 :去甲肾上腺素既能取消传入信息对体感皮层Ⅰ区神经元自发活动的兴奋效应 ;又能使其抑制作用减弱。结论 :去甲肾上腺素通过调制体感皮层Ⅰ区神经元的自发活动来改变信号一噪声比 ,影响体感皮
Objective: To investigate whether norepinephrine modulates the spontaneous activity of neurons in zone Ⅰ of somatosensory cortex and whether this modulation affects the sensation of somatosensory cortex to the afferent information. Methods: Sprague-Dawley rats were used as experimental subjects. Multi-tube glass microelectrode recording technique and micro-electrophoresis injection were used to observe the effects of different doses of norepinephrine and stimulation of saphenous nerve on the neurons in region Ⅰ of somatosensory cortex Changes in the average discharge rate of spontaneous activity during meta-analysis. Results: Noradrenaline facilitated the spontaneous activity of neurons in the electrophoretic region of somatosensory cortex Ⅰ and increased the average discharge rate. When the intensity of the microelectrophoresis increased gradually from 5nA to 145nA, the increase of the average discharge rate increased from (0.52 ± 0.47) pulses / s to (2 4.1 ± 6.9) pulses / s, which indicated Facilitation of gradual strengthening, and dose-effect - positive correlation between dependence. Norepinephrine has inhibitory effect on the spontaneous activity of neurons in somatosensory cortex Ⅰ region, but there is no dose-dependent relationship. Stimulation of the saphenous nerve current intensity is weak, only A class of fibers into the recording site when the neuronal spontaneous activity was inhibited; strong stimulus, Class A and C fibers together when the facilitation of recording site Spontaneous activity. Moreover, it was found that noradrenaline interacts with the modulation of afferent information on the spontaneous activity of neurons in somatosensory cortex Ⅰ. Norepinephrine not only excises the affective effect of afferent information on the spontaneous activity of neurons in somatosensory cortex Ⅰ, but also Can make its inhibitory effect weakened. CONCLUSIONS: Norepinephrine changes the signal-to-noise ratio by modulating the spontaneous activity of neurons in zone I of the somatosensory cortex, affecting somatosensory