Martin Prieto

Research Interests:

Ultrasound has a wide variety of applications in the biomedical sciences, but the biological effects of ultrasound on individual cells and molecules have rarely been studied using the quantitative and mechanistic methods of physiology and biophysics. I am interested in applying these methods to the interactions of ultrasound with cell membranes and membrane proteins.

This research is motivated by the recent demonstration of non-invasive activation of brain voltage-gated sodium channels by focused ultrasound, which suggests that ultrasonic modulation of brain activity may become a revolutionary new tool in behavioral neuroscience and in the treatment of neurological disorders. However, the mechanism of this effect is unknown. I hypothesize that ultrasound activates sodium channels through distortion of the surrounding lipid bilayer by ultrasonic radiation force, which modulates in turn modulates channel function through hydrophobic mismatch between the protein and the lipid bilayer. This is a general mechanism that should be applicable to all types of membrane proteins.

I have recently found that application of ultrasound to planar lipid bilayers causes oscillating capacitive currents at the onset and offset of the ultrasound stimulus. These currents probably represent changes in the area or thickness of the bilayer due to radiation force, consistent with my hypothesis. I an investigating how these capacitive currents depend on the composition of the lipid bilayer and how they affect the function of the canonical model ion channel gramicidin. Based on the results of these experiments, I will develop a model for the interactions between ultrasound, cell membranes, and membrane proteins. I will then test this model on lipid bilayers containing reconstituted sodium channels.

Favorite ice cream flavor: mango tangerine sorbet

Favorite movie: Easy Rider

Hometown: Rochester, NY

Hobby: Cooking

Favorite Wu-Tang Member: Ghostface Killah

Martin’s Stanford Profile Page

Contact: prieto at stanford dot edu