Optocapacitive Currents Elicited by Photolipid Excitation

Description

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.

Period	03 Aug 2023
Event title	EBSA Congress 2023
Event type	Conference
Location	SwedenShow on map