Student: Diane Iradukunda
Project Mentors: Dr. Jitendran Muthuswamy – SBHSE
Dr. Bruce Towe – SBHSE
Dr. Arati Sridharan – SBHSE
YouTube Link: View the video link below before joining the zoom meeting
Zoom Link: https://asu.zoom.us/j/99145331636
Zoom meeting time: 9am - 11am
Abstract
Nitric oxide is a gaseous, free radical which plays a role in coordinating neuronal network activity. It is produced by a group of enzymes known as nitric oxide synthases. Previous studies indicated that ultrasounds generate nitric oxide (NO) in vascular tissues mediated by stretch induced activation of endothelial nitric oxide synthase (eNOS). However, there is no evidence of similar generation of NO in neurons in response to incident ultrasound mediated by neuronal NOS (nNOS) and inducible NOS (iNOS). In this study, we investigated the relationship between the ultrasound intensity and NO generation in cortical neuronal cultures. Two different ultrasound intensities with spatial peak-temporal average (Ispta) of 10 and 30 W/cm2 at 2 different frequencies (1 and 3 MHz) were used to stimulate the neuronal cultures while quantifying NO release. This was done using diaminofluorescein-2 diacetate (DAF-2 DA) to detect the intracellular level of NO generated intracellularly with and without L-arginine. The addition of L-arginine to the cultured neuronal cells increases the production of NO. The fluorescent microscope was used to collect data of cultured neuronal cell images that contain DAF-2DA. Simultaneously, MatlabTM simulations were used to model the spatio-temporal distribution of pressure waveforms from the ultrasound transducer. We determined the dose-response relationship between ultrasound intensity and degree of NO release (corresponding to the DAF-2DA) and found a direct relationship between the increase of ultrasound intensity and the quantity of NO released. This study will help elucidate the effects of ultrasound on the mechanobiology of ion channels in neurons. Also, these results will provide additional insight into the neurochemical mechanisms of ultrasonic neuromodulation.