Transcranial ultrasound stimulation modulates neural activity of paraventricular thalamus and prefrontal cortex in the propofol-anesthetized mice.

Ultrasound stimulation applied to the thalamus before or after propofol anesthesia shortened the time to recovery of consciousness in mice. Mice receiving stimulation before anesthesia regained consciousness in about 20 minutes, and those stimulated after anesthesia in about 18 minutes, compared to about 33 minutes for sham-treated mice. The stimulation directly activated neural activity in the paraventricular thalamus and indirectly in the prefrontal cortex in the 60-100 Hz frequency band. Higher correlations in neural activity between these two brain regions were observed in the 8-13 Hz band, suggesting that both structures contribute to the transition of consciousness and can be modulated by transcranial ultrasound.

Study at a glance

Abstract

Objective: Transcranial ultrasound stimulation (TUS) has been reported to modulate neural activity and accelerate the recovery of consciousness in the propofol-anesthetized mice. Both the thalamus and frontal cortex play critical roles in anesthetic-induced transition of consciousness. Approach: Twenty-one male BALB/c mice were randomly divided into the Sham group (n=7), the TUS1 group (n=7) and the TUS2 group (n=7). The thalamus of mice in the two TUS groups were subjected to TUS before or after anesthesia, respectively. Local field potentials of paraventricular thalamus and prefrontal cortex were recorded using electrophysiological techniques. The relative change of mean absolute power and relative power in different frequency bands for each brain region were calculated and analyzed for correlation. Main results: Compared to the Sham group (33.14 ± 0.46 min), the time of recovery of consciousness was shorter in both the TUS1 group (19.86 ± 0.59 min) and TUS2 group (17.86 ± 0.86 min). Besides, the results showed that TUS could directly induce neural activity in the paraventricular thalamus and indirectly in the prefrontal cortex in the [60-100 Hz] frequency band. Furthermore, we also found that there were higher Pearson correlation coefficients (PCCs) of neural activity between paraventricular thalamus and prefrontal cortex in the [8-13 Hz] frequency band under TUS (P<0.05). Significance: Both the paraventricular thalamus and prefrontal cortex contribute to transition of consciousness in propofol-anesthetized mice, and they can be effectively modulated by TUS, which may provide a guidance for the modulation of consciousness in clinical anesthesia.