乌拉坦和氯胺酮麻醉条件下大鼠初级听皮层听觉神经元对纯音反应特性的比较(英文)  

Comparison of tonal response properties of primary auditory cortex neurons of adult rats under urethane and ketamine anesthesia

作　　者：黄玲玥[1] 柏林[1] 赵岩[1] 肖中举[1] 国“ 

机构地区：[1]南方医科大学基础医学院生理教研室,广东广州510515

出　　处：《南方医科大学学报》2013年第6期785-793,共9页Journal of Southern Medical University

基　　金：Supported by National Natural Science Foundation of China(31171059)~~

摘　　要：目的用在体细胞贴附式记录的方式，比较乌拉坦和氯胺酮麻醉条件下初级听皮层听觉神经元对纯音的反应特陛，探查两种麻醉剂对初级听皮层单个神经元纯音编码机制的影响。方法选取45只体质量200∽250g的spmgIle-Dawley雌陛健康大鼠，将其随机分为两组，分别用乌拉坦和氯胺酮作为基础麻醉剂，手术暴露初级听皮层。选取短纯音作为刺激条件，用在体细胞贴附式记录的方式获得大鼠初级听皮层的单个听觉神经元动作电位发放情况，并用Matlab软件提取动作电位的相关参数，分析两种麻醉剂对听神经元的声反应特性的影响。结果除了特征频率和Q值（特征频率与频率带宽的比值，反应听觉神经元的频率调谐特陛）以外，最小阈强度、自发放水平、声反应的潜伏期、刺激时间直方图以及频率．强度调谐曲线的类型均受到麻醉剂类型的影响。在乌拉坦麻醉条件下，声反应神经元对短声刺激表现出较高的阈强度、较低的自发放水平、较长的潜伏期，且接受较强抑制性频率．强度调谐曲线出现较频繁。结论乌拉坦和氯胺酮对声音频率信息在听觉通路中的传递无明显影响。但在乌拉坦麻醉条件下，初级听皮层神经元受到更强的抑制，这可能与乌拉坦能加强中间抑制性神经元的作用或抑制听神经元本身的兴奋性有关。Objective To compare tonal response properties of neurons in the primary auditory cortex of Sprague-Dawley rats anesthetized with urethane and ketamine-xylazine. Methods Forty-five female Sprague-Dawley rats （200-250 g） were randomized into two groups and anesthetized with urethane or ketamine-xylazine. Tone pips were chosen as the stimuli to obtain the action potentials of the single neurons by in vivo cell-attached recording. The features of the action potentials were extracted with Matlab software to comparatively analyze the acoustic response properties of the neurons between the two anesthetic groups. Results The Q values and the characteristic frequencies were independent of the types of anesthetic agents, but with urethane anesthesia, the neurons tended to have higher minimum thresholds, lower spontaneous firing rates, longer response latencies, and more frequent occurrence of tuning with stronger inhibition compared to those in ketamine-xylazine group. Conclusion Urethane and ketamine might have no obvious impact on the transmission pathway of frequency tuning from the periphery to the auditory cortex, but neurons from rats with urethane anesthesia receive enhanced inhibition mediated by the interneurons or have a lower intrinsic excitability.

关 键 词：乌拉坦 氯胺酮 初级听皮层 在体细胞贴附式记录 

分 类 号：R614[医药卫生—麻醉学]