目的 研究利多卡因对海马的神经毒性是否会对大鼠空间学习记忆能力产生影响，并探讨大鼠空间学习能力的变化与海马CA3区锥体细胞数目的相关性。 方法 将成年Wistar雄性大鼠随机分为基础值组（n=7）和利多卡因惊厥组（n=40）。基础值组大鼠静脉给予生理盐水后使用Y迷宫测定大鼠的空间学习能力。利多卡因惊厥组大鼠尾静脉持续输注利多卡因造成惊厥，待大鼠恢复正常运动以后放入鼠笼重新饲养。并于惊厥后第1、3、5、7天从中随机抓取大鼠测试其空间学习能力以及组织学改变。根据对应天数将利多卡因惊厥组的40只大鼠随机细分为Day-1、Day-3、Day-5、Day-7亚组，每亚组10只。所有大鼠在测定空间学习能力之后立即处死，取出大脑并做石蜡包埋，冠状面切片后进行组织学检测，显微镜下评估海马CA3区锥体细胞状态。 结果 ① 基础值组和Day-1、Day-3、Day-5、Day-7亚组大鼠的Y迷宫穿梭次数分别为（25.2 ± 3.7）、（27.1 ± 8.1）、（36.9 ± 9.9）、（38.7 ± 10.6）、（40.6 ± 16.3）次，除Day-1亚组与基础值组比较差异无统计学意义（P＞0.05）外，其余各亚组与基础值组差异均有统计学意义（P＜0.05）；② 与基础值组单位面积（10.3 ± 4.5）个（异常锥体）细胞比较，利多卡因惊厥组大鼠海马CA3区异常锥体细胞数增加，Day-1、Day-3、Day-5、Day-7亚组计数值分别为13.0 ± 7.2、15.6 ± 5.0、19.6 ± 8.1、18.1 ± 5.1，且与大鼠Y迷宫穿梭次数呈正相关（r=0.711，P＜0.05）。 结论 利多卡因引起的惊厥使成年大鼠海马依赖性空间学习能力下降，利多卡因的神经毒性引起的海马异常锥体细胞增多可能是造成这一现象的一种原因。
ObjectiveThe abnormal autophagy fluxis involved in the pathophysiological process of drug-resistance temporal lobe epilepsy (TLE).Hippocampal sclerosis (HS) is the main pathological type of drug-resistance TLE.Different subtypes of HS have various prognosis, etiology and pathophysiology.However, whether theabnormal block ofautophagy flux involved in this process has not been reported.This study proposed a preliminary comparison of autophagy fluxin typical and atypical HS to investigate the potential pathogenesis and drug-resistance mechanism of atypical HS. MethodsSurgical excision of hippocampal and temporal lobe epilepsy foci were performed in 17 patients with drug-resistance TLE.Patients were grouped according to the HS classification issued by International League Against Epilepsy in 2013.The distribution and expression of LC3B, beclin-1 and P62 were detected by immunohistochemistry and Western blot in each group. ResultsLC3B, beclin-1 and P62 are mainly expressed in neuronal cytoplasm, which is consistent with previous reports.Taking β-actin as internal reference, we found that LC3B and Beclin-1, the downstream products of autophagy flux, have increased significantly (P < 0.01) in the atypical HS group compared to typical HS group.However, the autophagy flux substrate P62 has no difference between the groups.This result suggested that compared with the typical HS group, atypical HS group had autophagy substrate accumulation and autophagy flux abnormal block.Besides, we found that glyceraldehycle-3-phosphate dehydrogenase(GAPDH) was significantly different between the two groups (P=0.003). ConclusionThere is abnormal phenomenon of autophagy flux in atypical HS, and GAPDH elevation may be involved in its mechanism, which might provide new targets and ideas for future treatment of atypical HS.
Currently, commercial devices for electrical neural stimulations can only provide fixed stimulation paradigms with preset constant parameters, while the development of new stimulation paradigms with time-varying parameters has emerged as one of the important research directions for expanding clinical applications. To facilitate the performance of electrical stimulation paradigms with time-varying parameters in animal experiments, the present study developed a well-integrated stimulation system to output various pulse sequences by designing a LabVIEW software to control a general data acquisition card and an electrical stimulus isolator. The system was able to generate pulse sequences with inter-pulse-intervals (IPI) randomly varying in real time with specific distributions such as uniform distribution, normal distribution, gamma distribution and Poisson distribution. It was also able to generate pulse sequences with arbitrary time-varying IPIs. In addition, the pulse parameters, including pulse amplitude, pulse width, interphase delay of biphasic pulse and duration of pulse sequence, were adjustable. The results of performance tests of the stimulation system showed that the errors of the parameters of pulse sequences output by the system were all less than 1%. By utilizing the stimulation system, pulse sequences with IPI randomly varying in the range of 5~10 ms were generated and applied in rat hippocampal regions for animal experiments. The experimental results showed that, even with a same mean pulse frequency of ~130 Hz, for neuronal populations, the excitatory effect of stimulations with randomly varying IPIs was significantly greater than the effect of stimulations with fixed IPIs. In conclusion, the stimulation system designed here may provide a useful tool for the researches and the development of new paradigms of neural electrical stimulations.
Febrile seizures (FS) are one of the most common neurological disorders in pediatrics, commonly seen in children from three months to five years of age. Most children with FS have a good prognosis, but some febrile convulsions progress to refractory epilepsy (RE). Epilepsy is a common chronic neurological disorder , and refractory epilepsy accounts for approximately one-third of epilepsies. The etiology of refractory epilepsy is currently complex and diverse, and its mechanisms are not fully understood. There are many pathophysiological changes that occur after febrile convulsions, such as inflammatory responses, changes in the blood-brain barrier, and oxidative stress, which can subsequently potentially lead to refractory epilepsy, and inflammation is always in tandem with all physiological changes as the main response. This article focuses on the pathogenesis of refractory epilepsy resulting from post-febrile convulsions.
This study aims to explore the diagnosis in patients with Alzheimer's disease (AD) based on magnetic resonance (MR) images, and to compare the differences of bilateral hippocampus in classification and recognition. MR images were obtained from 25 AD patients and 25 normal controls (NC) respectively. Three-dimensional texture features were extracted from bilateral hippocampus of each subject. The texture features that existed significant differences between AD and NC were used as the features in a classification procedure. Back propagation (BP) neural network model was built to classify AD patients from healthy controls. The classification accuracy of three methods, which were principal components analysis, linear discriminant analysis and non-linear discriminant analysis, was obtained and compared. The correlations between bilateral hippocampal texture parameters and Mini-Mental State Examination (MMSE) scores were calculated. The classification accuracy of nonlinear discriminant analysis with a neural network model was the highest, and the classification accuracy of right hippocampus was higher than that of the left. The bilateral hippocampal texture features were correlated to MMSE scores, and the relative of right hippocampus was higher than that of the left. The neural network model with three-dimensional texture features could recognize AD patients and NC, and right hippocampus might be more helpful to AD diagnosis.