经颅磁声电刺激下大鼠工作记忆中前额叶皮层因果连接网络特性分析

Analysis of the Causal Connection Network Characteristics of Prefrontal Cortex in Working Memory of Rats under Transcranial Magneto-Acousto-Electrical Stimulation

经颅磁声电刺激(TMAES)是一种新型非侵入式的脑神经调控技术,利用静磁场和超声波耦合在脑组织中产生刺激电流以调节特定脑区的神经放电活动。本研究旨在从神经节律振荡与信息传递的角度,探究经颅磁声电刺激对大脑工作记忆功能的影响。将24只斯普拉格·道利(SD)大鼠随机分为对照组、超声组和磁声组,磁声组接受0.10 T、7.98 W/cm^(2)的刺激,超声组接受相同强度的超声刺激,对照组不接受刺激;采集T迷宫工作记忆实验中大鼠前额叶皮层的局部场电位(LFPs)信号,对比不同组别θ(4~8 Hz)和γ(30~80 Hz)频段LFPs信号的时频分布,并基于图论进一步分析前额叶皮层的因果连接网络特性。结果显示,磁声组大鼠在行为选择过程中θ和γ频段LFPs信号的能量值大于超声组与对照组(P<0.05);磁声组信号间平均因果连接强度高于超声组和对照组(P<0.05);磁声组大鼠工作记忆任务中θ频段因果连接网络的全局效率(E_(glob))和聚类系数(C)比超声组和对照组显著升高(磁声组:E_(glob)=0.134±0.033,C=0.837±0.071;超声组:E_(glob)=0.099±0.032,C=0.713±0.111;对照组:E_(glob)=0.068±0.022,C=0.554±0.118,P<0.05);磁声组γ频段因果连接网络的全局效率、聚类系数比超声组和对照组显著升高(磁声组:E_(glob)=0.116±0.031,C=0.789±0.106;超声组:E_(glob)=0.087±0.018,C=0.641±0.135;对照组:E_(glob)=0.066±0.012,C=0.480±0.091,P<0.05)。研究表明,TMAES增强了θ和γ节律神经放电活动,促进大鼠行为选择期间神经元集群之间的信息交互,提高工作记忆相关信息的传递效率,为进一步揭示经颅磁声电刺激调控大脑记忆功能的深层作用机制提供支持。

Transcranial magneto-acousto-electrical stimulation(TMAES)is a new non-invasive brain neuromodulation technology that uses static magnetic field and ultrasonic coupling to generate stimulation currents in the brain tissue to regulate neural discharge activity in specific brain regions.The purpose of this paper is to explore the effects of TMAES on the working memory function from the perspective of neural rhythm oscillation and information transmission.Fifteen Sprague-Dawley(SD)rats were randomly divided into control group,ultrasound group,and TMAES group,with the TMAES group applying 0.10 T,7.98 W/cm^(2)stimulation,the ultrasound group receiving the same intensity of ultrasound stimulation,and the control group receiving no stimulation.The local field potentials(LFPs)signals of rat prefrontal cortex in T-maze working memory experiment were collected.The time-frequency distribution of LFPs signals inθ(4~8 Hz)andγ(30~80 Hz)bands of different groups was compared,and the causal connection network characteristics of prefrontal cortex were further analyzed based on graph theory.The experimental results showed that the energy values ofθandγ-band LFPs signals in the TMAES group were higher than that of the ultrasound group and the control group during the behavior selection process(P<0.05).The causal connection strength between the signals in the TMAES group and the ultrasound group was higher than that of the control group(P<0.05).The global efficiency and clustering coefficient ofθband causal connection network in working memory task of the TMAES group were significantly higher than those in the TUS group and the control group(TMAES group:E_(glob)=0.134±0.033,C=0.837±0.071;TUS group:E_(glob)=0.099±0.032,C=0.713±0.111;control group:E_(glob)=0.068±0.022,C=0.554±0.118,P<0.05).The global efficiency and clustering coefficient ofγband causal network in the TMAES group were significantly higher than those in the TUS group and control group(TMAES group:E_(glob)=0.116±0.031,C=0.789±0.106;TUS group:E_(glob)=0.116±0.031,C=0.789±0.106;control group:E_(glob)=0.066±0.012,C=0.480±0.091,P<0.05).Our studies have shown that TMAES enhancedθandγrhythm neural discharge activities,promoted the information interaction between neurons during behavioral selection in rats,and improved the transmission efficiency of working memory-related information,which would provide support for further revealing the deep mechanism of TMAES stimulation regulating brain memory function.