Effects of transcranial magneto-acoustical stimulation on beta oscillations in neural circuits of healthy and Parkinson's disease rats / 中国组织工程研究

ABSTRACT

BACKGROUND:Transcranial magneto-acoustical electrical stimulation(TMAES)is a non-invasive,high-precision neurofocused stimulation method based on magneto-acoustic coupling electrical effect,which can regulate the rhythmic oscillation of nerve activity,thereby affecting the brain's movement,cognition and other functions. OBJECTIVE:To explore the effect of TMAES on beta oscillations in the neural circuits of healthy rats and Parkinson's rats. METHODS:(1)Animal experiments:Twenty-four Wistar rats were randomly divided into four groups(n=6 per group).The rats in the normal control group received no intervention,while those in the normal stimulation group received TMAES(the average spatial peak pulse intensity:13.33 W/cm2,fundamental frequency:0.4 MHz,the number of fundamental wave cycles:1000,and pulse frequency:200 Hz).The model control group and model stimulation group were established by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine.After successful modeling,the rats in the model control group received sham TMAES stimulation in the prefrontal cortex,and those in the model stimulation group received TMAES in the prefrontal cortex,and the duration of stimulation was 2.0 minutes per day.After an interval of 8-10 minutes,the local field potential signals of rats were collected during the execution of T-maze test and the correct rate of behavior was recorded at the same time to compare and analyze the time-frequency distribution of local field potential signals and behavioral differences among the groups.The stimulation experiment and T-maze test were stopped when the correct rate of rats was higher than 80%for 3 consecutive days.(2)Modeling and simulation experiments:The cortical-basal ganglion circuit model under TMAES was established,and the ultrasonic emission period(5,10,20 ms),ultrasonic emission duty cycle(30%,50%,90%)and induced current density(20,50,100 μA/cm2)were changed respectively to compare the power spectral density values of beta oscillations in healthy rats and Parkinson's rats under different stimulation parameters. RESULTS AND CONCLUSION:(1)Animal experiments:The spatial learning ability of the rats in the normal control group was stronger than that of the model control group(P＜0.001),the spatial learning ability of the rats in the normal stimulation group was stronger than that of the normal control group(P＜0.05),and the spatial learning ability of the rats in the model stimulation group was stronger than that of the model control group(P＜0.01).The distribution of beta oscillation energy in the normal control group was more concentrated,and the beta oscillation signal energy was reduced in the normal stimulation group compared with the normal control group.The beta oscillation energy was widely distributed and the energy value was significantly higher in the model control group and the model stimulation group than the normal control and normal stimulation groups.Moreover,the beta oscillation signal energy in the model stimulation group was significantly lower than that in the model control group.(2)Modeling and simulation experiments:the peak power spectral density of the beta band of healthy rats without stimulation(30 dB)was significantly lower than that of Parkinson's rats(55 dB).The power spectral density value generally decreased after stimulation.The peak power spectral density in the beta band was positively correlated with the ultrasonic emission period and negatively correlated with the induced current density.In addition,the peak power spectral density value was the lowest when the duty cycle of ultrasonic emission was 50%.These findings indicate that TMAES suppresses beta oscillations in healthy and Parkinson's disease rats,thereby improving motor function and decision-making cognitive function in rats.