电刺激诱导后放电对小鼠初级听皮层神经元纯音反应的影响

发布时间：2018-04-02 17:03

本文选题：乌拉坦　切入点：氯胺酮　出处：《重庆医科大学》2014年博士论文

【摘要】：第一部分乌拉坦和氯胺酮麻醉条件下电刺激诱导小鼠后放电特征的比较目的：比较乌拉坦和氯胺酮麻醉下电刺激小鼠前额叶皮层诱导后放电发作的特点。方法：取4-6周龄的雌性C57/6J小鼠共20只，分别采用乌拉坦和氯胺酮麻醉，每组各10只。而后于前额叶皮层给予时长1ms频率60Hz串长1s间隔1min的双向电刺激，起始强度700uA，直至脑电图记录到大于等于5s的后放电发作。而后每隔10min给予一次与诱出后放电时强度相同的电刺激，共20次，连续记录脑电图，采用快速傅里叶转换对两组小鼠后放电发作的脑电图进行频率能量分布分析。结果：乌拉坦组10只小鼠中3只未诱出后放电，氯胺酮组中4只未诱出。乌拉坦组小鼠平均需38.67±2.88次电刺激诱导出首次后放电发作，氯胺酮组小鼠平均需74.17±3.39次电刺激诱出首次后放电。随着电刺激数增加，两组小鼠后放电发作持续时间呈增加趋势。能量频率分布显示，后放电发作前，两组小鼠脑电图均以δ和θ波为主，后放电发作时，γ和β频率增多，乌拉坦组以γ频率增多为主，氯胺酮组以β频率增多为主，两组差异有统计学意义（p0.05）；后放电发作停止后，两组小鼠脑电图γ和β频率降低，δ和θ频率增高。结论：乌拉坦和氯胺酮麻醉下重复电刺激前额叶皮质均能诱导后放电发作，两组小鼠后放电脑电图形态近似，频率分布略有不同。第二部分电刺激诱导后放电对小鼠初级听皮层神经元纯音反应的影响目的：观察电刺激诱导后放电对小鼠初级听皮层神经元纯音反应的影响。方法：取4-6周龄的雌性C57/6J小鼠共16只，氯胺酮麻醉后，放置钨电极于小鼠左侧初级听皮层（AI区），给予不同频率和强度的纯音（20ms）进行频率/阈值调谐曲线扫描，，得到最小阈值和最佳频率，以声强为最小阈值以上10dB SPL，频率同最佳频率，时长20ms间隔2s的纯音为声刺激，重复225次，细胞外记录初级听皮层神经元对该纯音刺激的反应。然后于前额叶皮层放置刺激电极，给予时长1ms频率60Hz串长1s间隔1min的双向电刺激，直至脑电图记录到后放电发作。而后每隔10min给予一次与诱出后放电时强度相同的电刺激，并于每次电刺激结束即刻给予同前参数的纯音刺激，细胞外记录初级听皮层神经元反应。共进行20次电刺激，而后停止电刺激，重复一次频率/阈值调谐曲线扫描，而后继续给予每组重复225次参数同前的纯音刺激，记录后放电发作停止后初级听皮层神经元对纯音刺激的反应。结果：16只小鼠中10只诱导出后放电，诱出后放电的小鼠平均需70.5±3.81次电刺激诱导出首次后放电发作；随着电刺激数增加，后放电发作持续时间呈增加趋势。频率/阈值调谐曲线显示后放电发作前后小鼠的平均最佳频率，平均最小阈值，最小阈值10dB SPL以上及30dBSPL以上平均频率带宽，最小阈值10dB SPL及20dB SPL以上纯音发放时神经元平均放电数，以及频率反应曲线的差异均无统计学意义（p0.05）。随着后放电次数增多，小鼠初级听皮层神经元对纯音刺激反应的放电数呈增加趋势，后放电发作停止后，神经元反应放电数降回至基线水平，与后放电发作前及发作后相比，发作期神经元平均放电数明显增高，差异有统计学意义（p0.05）。后放电发作期小鼠初级听皮层神经元反应峰值放电数及放电起始至放电峰值斜率较发作前后增高，但差异无统计学意义。后放电发作期初级听皮层神经元对纯音刺激的反应潜伏期和声反应达峰值所需时间无明显改变。结论：重复电刺激前额叶皮质诱导后放电发作使初级听皮层神经元对纯音刺激反应的放电数明显增加，后放电发作对小鼠初级听皮层神经元频率/阈值调谐曲线、反应潜伏期、反应达峰值所需时间和放电起始至放电峰值斜率无明显影响。
[Abstract]:The characteristics of electric stimulation induced by electric stimulation in the first part of uran and ketamine
Objective: To compare the characteristics of electric stimulation of the prefrontal cortex induced by electric stimulation of uran and ketamine in the prefrontal cortex of mice.
Methods: 4-6 week old female C57/6J mice were 20, respectively with urethane and ketamine anesthesia, 10 rats in each group. Then in the prefrontal cortex give bidirectional electric length 1ms frequency 60Hz on long 1s interval of 1min stimulation, the initial strength 700uA, until the EEG recorded after the ictal discharge is greater than or equal to 5S. Then every 10min given once and to discharge the same intensity after electrical stimulation, a total of 20 times, continuous recording of EEG, using fast Fourier transform to analyze the frequency energy distribution of EEG ictal discharge after two groups of mice.
Results: the urethane group of 10 mice in 3 did not elicit after discharge, not only to 4 in the ketamine group. Urethane group mice average 38.67 + 2.88 times of electric stimulation induced ictal discharge for the first time after the export, ketamine group mice average 74.17 + 3.39 times for the first time to discharge after electrical stimulation. With the increase in the number of electrical stimulation, two groups of mice after discharge seizure duration increased. The energy frequency distribution showed that after discharge before the onset, two groups of mice were dominated by EEG delta and theta, after discharge occurs, gamma and beta frequency increased, the urethane group dominated by gamma frequency increase, ketamine group mainly beta frequency increased there was significant difference between two groups (P0.05); after discharge seizure stopped after two groups of mice EEG gamma and beta frequency decreases, Delta and theta frequency increased.
Conclusion: repeated electrical stimulation of prefrontal cortex can induce post discharge seizures under urethane and ketamine anesthesia. After two groups of mice, the patterns of computerized electrograms are similar and the frequency distributions are slightly different.
The effect of the second part of electrical stimulation induced discharge on the pure tone response of the mouse primary auditory cortex neurons
Objective: To observe the effect of electrical stimulation induced discharge on the pure tone response of the primary auditory cortex neurons in mice.
Methods: 4-6 week old female C57/6J mice were 16 rats after ketamine anesthesia, placement of tungsten electrode in mice left primary auditory cortex (AI), pure tone with different frequency and intensity (20ms) frequency / threshold tuning curve scanning, get the minimum threshold and the optimal frequency, sound intensity is above a minimum threshold to 10dB SPL, the frequency with the best frequency pure tone, long 20ms interval 2S for acoustic stimulation, repeated 225 times, extracellular recording of primary auditory cortex neurons to the tone stimulus response. Then in the prefrontal cortex stimulation electrode placed, bidirectional power give long 1ms frequency 60Hz on long 1s interval 1min stimulation, until the EEG recording to discharge after the attack. Then every 10min given once and to discharge the same intensity after electrical stimulation, electrical stimulation and pure tone at each end with the stimulation parameters given immediately, extracellular recording of the primary auditory cortex of anti . a total of 20 times and then stop electrical stimulation, electrical stimulation, repeat frequency / threshold tuning curve scanning, and then continue to repeat 225 times with the parameters of pure tone stimulus, after recording the ictal discharge after cessation of primary auditory cortex neurons to tone stimulus response.
Results: the 16 mice in 10 rats induced after discharge, discharge after the mice to average 70.5 + 3.81 times of electric stimulation induced ictal discharge for the first time after the export; with electrical stimulation increased after discharge seizure duration increased. The frequency / threshold tuning curves display after discharge before and after the onset of mice average optimal frequency the average minimum threshold, above the minimum threshold of 10dB SPL 30dBSPL and above average frequency bandwidth, the minimum threshold of 10dB SPL and 20dB SPL issued above pure tone average discharge neurons number, frequency response curve and the differences were not statistically significant (P0.05). With the increased number of mice after discharge, the number of primary auditory cortex neurons to discharge stimulation reaction increased after discharge seizure stopped after discharge number neurons reduced back to baseline, and after discharge seizure before and after the onset of exacerbation compared to neural element average The electric number increased significantly, the difference was statistically significant (P0.05). After the discharge onset of primary auditory cortex neurons of mice and the number of initial discharge discharge peak to peak discharge before and after the onset of slope was increased, but the difference was not statistically significant. After discharge onset of primary auditory cortex neurons in response latency and response to pure tone stimuli reached peak time has no obvious change.
Conclusion: repeated electrical stimulation of prefrontal cortex after discharge seizure to primary auditory cortex neurons of discharges tone stimulation increased significantly after discharge seizure of mouse primary auditory cortex neurons / frequency threshold tuning curves, peak latency, reaction had no significant effect on the required time and initial discharge to discharge peak slope.

【学位授予单位】：重庆医科大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R742.1

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