Transcranial focused ultrasound to the thalamus alters anesthesia time in rats.

A pulsed application of focused ultrasound (FUS) to the regional brain tissue alters the state of tissue excitability and thus provides the means for noninvasive functional neuromodulation. We report that the application of transcranial FUS to the thalamus of anesthetized rats reduced the time to emergence of voluntary movement from intraperitoneal ketamine/xylazine anesthesia. Low-intensity FUS was applied to the thalamus of anesthetized animals. The times required for the animals to show distinct physiological/behavioral changes were measured and compared with those times required in a control session without sonication. The sonication significantly reduced the time to show pinch response and voluntary movement. The modulatory effects of FUS on anesthesia suggest potential therapeutic applications for disorders of consciousness such as minimally consciousness states.