The Effects Of Ultrasound Stimulation On Neurovascular Coupling In Mice With Different States

Transcranial ultrasound stimulation(TUS)allows non-invasive and precise focusing on targeted areas in the brain.This highly targeted but non-invasive neuromodulation technique offers the possibility of new therapies for many neurological disorders.The local field potential(LFP)represents the sum of the activity of a large number of neurons in the vicinity of the microelectrodes and is the potential recorded in the extracellular space of brain tissue.Cerebral oxygen saturation can reflect changes in hemodynamics.Although existing studies have confirmed that TUS can induce neural oscillations and hemodynamic responses,the response to ultrasound stimulation at different levels of anesthesia remains unclear.First,the research background and significance of this experiment are introduced,and the progress of low-intensity transcranial ultrasound in neuromodulation in animals is summarized.Then the principle and construction of the experimental platform of lowintensity transcranial ultrasound and the processing method of the acquired EEG signals and optical images are described in detail.Subsequently,the effects of different anesthetic durations and anesthetic sequences on ultrasound stimulation experiments were investigated on the constructed experimental platform.The experimental results showed that the mean amplitude and mean relative power of the LFP-filtered sharp wave-ripple(SPW-R)(160-200Hz)signal and the hemodynamic response both tended to decrease gradually with increasing time.The order of anesthesia was also found to affect the experimental results.Finally,based on the above study,we designed experiments to analyze the neural oscillations and hemodynamic changes induced by ultrasound and the coupling relationship between them in mice given ultrasound stimulation at different levels of anesthesia and ultrasound intensity.The experimental results showed that the mean amplitude(MAMP)and mean relative power(MRP)percentage changes of the SPW-R signal induced by ultrasound stimulation decreased gradually with increasing anesthesia level,and the hemodynamic response also decreased gradually.In contrast,these values gradually increased with increasing ultrasound intensity.In conclusion,the effect of transcranial ultrasound stimulation is deeply dependent on the degree of anesthesia and ultrasound stimulation intensity,and this study provides a new research tool to explore the mechanism of brain activity.