帕金森病丘脑底核神经元的电活动特点

本研究探讨了帕金森病(Parkinson′sdisease, PD)患者丘脑底核(subthalamic nucleus, STN)神经元电活动的特点及其与PD症状的关系.35例PD患者在接受手术治疗的同时, 应用微电极细胞记录和EMG记录技术,记录手术靶点STN及其周围结构神经元的电活动以及手术对侧肢体的EMG.应用分析软件甄别单细胞电活动, 分析其特点及其与肢体EMG的关系.结果表明, STN及其周围结构具有特征性放电活动.在36个记录针道中,共发现436个STN神经元, 平均放电频率44.0±20.5 Hz. 其中, 56%的神经元呈不规则簇状放电;15%呈紧张性放电; 29%呈规则的簇状放电, 其放电节律与肢体震颤的EMG高度一致(r2=0.66,P<0.01), 称之为震颤细胞. 在PD震颤型患者的STN中发现大量震颤细胞,且80%位于STN中上部, 而在PD僵直型患者的STN中均发现与运动相关的细胞电活动.本研究提示, 通过微电极记录技术可准确地判断STN的位置和范围;与震颤活动相关的细胞放电和与运动相关细胞的放电与PD症状有内在关系;STN参与PD运动障碍的病理生理过程.

Characteristics of subthalamic neuronal activities in Parkinson's disease

The relationship between neuronal activity in subthalamic nucleus (STN) and parkinsonian symptoms was investigated. Thirty-five patients with idiopathic Parkinson's disease (PD) received stereotactic surgical treatment. Microelectrode recording in STN and electromyography (EMG) on the limb contralateral to the surgical side were employed intraoperatively. Single unit firings discriminated from multiple neuronal discharges were recorded, and the correlation between neuronal activity and limb EMG was analyzed. The results showed that there were distinguished characteristics of neuronal discharges in STN and its surrounding areas. Of 346 STN neurons recorded from 36 microrecording trajectories in 35 patients, three patterns of neuronal activities were identified: irregular bursting pattern with a mean frequency of 43.0+/-11.2 Hz (56%, n=244); tonic firing pattern with a mean firing frequency of 41.0+/-12.0 Hz (15%, n=66); and regular bursting pattern with a mean frequency of 47.0+/-11.7 Hz (29%, n=126). The rhythm of regular bursting with the frequency ranging from 3.8 to 6.0 Hz was highly correlated with the frequency of limb tremor measured by EMG (r(2)=0.66, P<0.01). These cells were therefore called tremor-related neurons or tremor cells. In particular, 80% tremor cells were located in the medio-superior part of STN. In conclusion, our results suggest that microelectrode recording is a critical technique for electrophysiological localization of the target in treating PD. The tremor-related neuronal activity and movement-related neuronal activity recorded from STN are responsible for the clinical parkinsonian symptoms, suggesting that STN plays an important role in the pathophysiology of PD.