超声刺激对大鼠前额叶皮层ECoG的调控

超声刺激具有神经调控功能,探讨其对前额叶皮层的神经调控作用及机制.超声刺激经颅施加到麻醉状态下大鼠(n=15)的前额叶皮层(刺激持续20 min),并于刺激前、刺激中和超声刺激后分别记录前额叶皮层的皮层电位(ECoG).ECoG的特征参数分别为总功率谱密度(PSD)、4个频段(δ:0.5～4 Hz,θ:4～8 Hz,α...

Ultrasound Stimulation on ECoG in Rat Prefrontal Cortex

Ultrasound stimulation has neuromodulatory function. In the present study, we explored the neuromodulatory effect and mechanisms of ultrasound stimulation on prefrontal cortex. Ultrasound stimuli were applied transcranially to the prefrontal cortex of anesthetized rats (n=15) and electrocorticogram (ECoG) was recorded before, during (20 min) and after the ultrasound stimulation. The characteristic parameters of ECoG included the total power spectral density (PSD), the PSD of four frequency bands (δ: 0.5～4 Hz, θ: 4～8 Hz, α: 8～13 Hz, β: 13～30 Hz), the average amplitude of ECoG and the average amplitude of the four frequency bands. To attenuate individual differences between experimental rats and reveal the time-effect relationship of ultrasound stimulation, the characteristic parameter values of ECoG during and after ultrasound stimulation were statistically compared and analyzed in the form of percentages relative to pre-stimulation (defined as 100%). The results could be described from four aspects. 1) The whole ultrasound stimulation process was divided into 7 time periods, which were 0~1, 1~2, 2~3, 3~4, 4~5, 5~10,10~20 min of ultrasound stimulation, respectively. The total PSD of ECoG was 139.2±13.2% in prefrontal cortex within 1 min of the applied ultrasound stimulation, and the difference was significant compared with that before the stimulation (P<0.05). The differences between the total PSD of ECoG in the other 6 time periods compared to pre-stimulation were all significant (P<0.05). Within 5 min after the cessation of ultrasound stimulation, the PSD of ECoG was 90.1±9.9% of that before stimulation, and the difference was not significant compared with that before stimulation (P>0.05).2) Ultrasound stimulation had an enhancing effect on PSD in all four frequency bands, and the difference between PSD in all four frequency bands in ultrasound stimulation and before stimulation was significant (P<0.05). After the cessation of ultrasound stimulation, there was no significant difference between the PSD of the four frequency bands compared with that before stimulation (P>0.05). 3) Mean amplitude of ECoG: Thechange of mean amplitude of ECoG in ultrasound stimulationwas significant compared with that before stimulation (P<0.05); After ultrasound stimulation was stopped, the difference was not significant compared with that before stimulation (P>0.05). 4) For the mean amplitude of the four frequency bands, ultrasound stimulation could enhance the mean amplitude of the four frequency bands. Furthermore, this enhancement was manifested in the δ band up to 10 min, and the enhancement in the θ, α and β bands was less than 5 min. Ultrasound stimulation regulated ECoG in rat prefrontal cortex and this regulation has the characteristics of promptness and rapid recovery.