The Kobertz Lab was recently awarded an Obama BRAIN initiative grant
The Kobertz Lab was recently awarded an Obama BRAIN initiative grant to develop a novel approach to visualize potassium efflux in the brain. Visualizing cellular efflux has been challenging because it’s opposite to the conventional intracellular-centric experimental paradigm that permeates all of cell and neurobiology: “If potassium were so important”, ridicule the neuroscientists, “why do neurons get rid of it during brain activity?”
However, potassium is the brain’s currency: it’s used by neurons to terminate action potentials, glia absorb it and can spritz it on smooth muscle cells to regulate cerebral artery diameter. Dysfunctional potassium activity has been implicated in multiple sclerosis, epilepsy, cortical spreading depression, neurodegenerative disorders, and some forms of neuropathic pain.
Consequently, modulating potassium fluxes in the brain has been proposed as a potential treatment for neurological diseases even though physiological and pathophysiological levels of extracellular potassium cannot be currently imaged. Therefore, we have been developing a general approach to fluorescently visualize cellular efflux (video of proton efflux). The advantage of our technology is that it enables researchers to visualize ion efflux over the entire landscape of a cell, tissue slice, and potentially intact organs in living animals.
For the BRAIN initiative award, the organic chemists in the lab have already synthesized the first near-IR fluorescent sensor for potassium, which will enable future in vivo imaging of potassium because there is less background noise and better tissue penetration with longer wavelengths of light that are beyond the visible spectrum. The goal over the next two years is to specifically attach near-IR fluorescent potassium sensors to the surfaces of different cells and watch potassium fly! It’s going to be pretty exciting in the lab – and for someone who has studied the ugly cation for over 15 years – it’s going to be fun to make movies of potassium as it leaves the cell and matures into a swan.