Sorina Munteanu is a rising Junior at University of California Merced majoring in Bioengineering. Sorina is working in Dr. Guy Genin’s lab analyzing oocytes from Xenopus laevis (African clawed frog) to determine the effects ultrasounds have on mechanosensitive ion channels. In the future, Sorina would like to become a physician scientist and conduct translational research on neurodevelopmental diseases.
Strain Mapping to Identify the Mechanisms by which Ultrasound Activates Ion Channels
Ultrasound imaging can be used as a therapeutic tool for neurological disorders through stimulation of certain mechanosensitive ion channels. However, the molecular mechanism through which these ion channels are activated is unknown. We hypothesize that ultrasound can cause a mechanical force that deforms the cells, thus activating ion channels. To test this hypothesis, Xenopus oocyte membranes will be analyzed in vitro by confocal microscopy to further elucidate the deformation caused by ultrasound. To evaluate whether ion channel activation relates to mechanical strain, these experiments require real-time estimations of strain fields over the oocyte membrane. We therefore developed a method by which stacks of confocal images could be computationally and quantitatively observed to reveal mechanical changes. Through strain mapping under two- and three-dimensional conditions, the deformation is quantified through displacement tracking. With three-dimensional renderings of the oocytes under strain, normal vectors reveal the expansion or shrinkage of the membrane in the xy plane. Thus, the strain fields could be estimated for subsequent correlation with the activation of mechanosensitive ion channels. We show that the controlled membrane expands laterally and retracts longitudinally as tension is applied at magnitudes that are reasonable estimates of those expected from loading by ultrasound. Elucidating the mechanisms of ultrasound on mechanosensitive ion channels may provide the field of neuroscience with a powerful tool that is comparable to techniques such as optogenetics. The underlying mechanisms of ultrasound could be applied clinically as a therapeutic modality for diseases such as Parkinson’s, depression, and anxiety.