Optocapacitive Currents Elicited by Photolipid Excitation
Sprache des Vortragstitels:
Englisch
Original Tagungtitel:
EBSA Congress 2023
Sprache des Tagungstitel:
Englisch
Original Kurzfassung:
Sudden changes in membrane cation permeability elicit action potentials in excitable cells. Light exposure may trigger them if the plasma membrane harbors light-sensitive ion channels (channelrhodopsins). Yet, fast jumps in membrane capacitance
may render such channels superfluous, as experiments with photothermally active membrane-bound nanoparticles have shown. We now propose a further simplification of the approach. It does not require channelrhodopsins or light-absorbing nanoparticles. Instead, we use photolipids with acyl
chains that contain azobenzene moieties. Their light-triggered reversible photoisomerization is responsible for the change in membrane capacitance. As shown by our experiments on planar bilayers, these capacitance changes are the source of optocapacitive current. The magnitude of the
current spikes depends on the light intensity, photolipid concentration, and membrane compressibility. We observe similar optocapacitive currents in cells containing the photolipids in their plasma membranes. These cells exhibit light-induced action potentials in the absence of
channelrhodopsins. Our observation paves the way for the use of photolipids for neuronal stimulation.