The Effect Of Transcranial Ultrasound On Cerebral Blood Flow In Mice Based On Laser Speckle Imaging

At present,in studies of neurological imaging,changes in local cerebral blood flow induced by sensory stimuli are often regarded as a sign of cerebral nervous system activity,but the spatiotemporal characteristics of local cerebral blood flow responses combined with ultrasound stimulation have never been described completely and clearly.Transcranial ultrasound stimulation a new method of brain regulation developed in recent years.It transfers low-intensity ultrasound energy through the entire skull to produce biomechanical effects on neurons,thereby non-invasively regulating nerves in the brain.Activity,compared with traditional medical treatment,deep brain stimulation or magnetic stimulation,it has the advantages of non-invasive,high penetration depth and high spatial resolution.This article introduces the principle and current status of transcranial ultrasound stimulation and the principle of laser speckle ratio imaging technology.We set up two sets of transcranial ultrasound stimulation systems,and the system components and parameters are introduced.In this paper,we used laser speckle imaging and transcranial ultrasound stimulation system to make two different experiments:1)Under anesthesia,we used ultrasound to stimulate the thalamus of mice.And the body's cortical somatosensory area was continuously imaged to monitor the local cerebral blood flow response of the corresponding area of the cortex when the mouse was under ultrasound stimulation.The results show that we use ultrasound to stimulate the thalamus of mice can change the cerebral blood flow velocity of the somatosensory cortex and accelerate the cerebral blood flow velocity of mice,it provides a new method for exploring the mechanism of brain activity.2)In the awake state,the mice were visually stimulated.We sued laser speckle to image the visual cortex of the mice,and we observed whether the mice's blood flow changed after visual stimulation.Then,the mouse visual cortex was subjected to ultrasonic stimulation to observe whether the ultrasonic stimulation had an effect on blood flow in the mouse visual cortex.Finally,the left eye of the mouse was stimulated with light and the ultrasound was used to stimulate the visual cortex of the mouse,and the blood flow was observed.The experimental results show that visual stimulation,ultrasonic stimulation,and simultaneous visual and ultrasonic stimulation can accelerate blood flow changes in the mouse visual cortex.