Fig. 5.

Neuronal application of MerMAID6 as optogenetic silencer. a CA1 pyramidal neuron expressing MerMAID6-Citrine (green) 5 days after electroporation (stitched maximum intensity projections of two-photon images). mCerulean (magenta) was co-electroporated to visualize neuronal morphology (left). Fluorescence intensity shown as inverted gray values (right). b, c Voltage traces in response to depolarizing current ramps injected into MerMAID6-expressing CA1 pyramidal cells. Illumination with green light (500 nm, 10 mW/mm2) for a brief (10 ms, b) or longer (500 ms, c) time period blocked single spikes. Light onset preceded action potential onset (measured in the dark condition) by 5 ms. d Same as c but a depolarizing current step of 300 pA was injected into the neuron instead of a current ramp