Project Summary
Transcranial current stimulation (TCS) creates small electrical fields in the brain through electrodes placed on
the scalp. As a method for neuromodulation, TCS carries with it many practical benefits: it is portable (battery-
operated), inexpensive, and easily deployable in the clinic and at home. Due to this simplicity and apparent
versatility there has been an explosion in the number of studies currently underway using transcranial currents
(over 500 clinical trials on clinicaltrials.gov).
Despite this ubiquity and potential, even basic questions about the nature of neural changes induced by various
forms of TCS have not been answered in-vivo. This lack of understanding of the underlying biology has led to
skepticism about the method. Moreover, refinement of the technique as used in humans is limited to a relatively
inefficient process that proceeds largely by trial and error.
This project will use state-of-the-art imaging techniques in awake mice to gain insight how TCS affect changes
in neural activity. The project will use the exquisite spatial resolution of two-photon imaging, together with genetic
methods to target specific cell populations, to reveal how TCS affects neural activity in a cell-type, and layer
specific manner. This high-spatial resolution technique will be complemented with high temporal resolution
voltage sensitive dye imaging to assess the temporal aspects of these induced changes, including the
entrainment of oscillations.
Together these complementary approaches will provide insight how TCS affects neural activity at an
unprecedented level of detail. This insight - for instance understanding whether all cell-types are affected equally,
or the TCS dose needed to achieve meaningful entrainment of neural activity - is essential for the rational
development of targeted TCS protocols.