Multiple-Color Optical Activation, Silencing, and Desynchronization of Neural Activity, with Single-Spike Temporal Resolution
Figure 1
Millisecond-timescale Halo-mediated neuronal hyperpolarization, elicited by pulses of yellow light.
(A) A representative cultured hippocampal neuron expressing mammalian codon-optimized N. pharaonis halorhodopsin (abbreviated Halo) fused to GFP, under the CaMKII promoter. Scale bar, 20 µm. (B) Neuronal currents elicited by optical activation of Halo. Left, representative outward currents elicited by two 1-second pulses of yellow (560±27.5 nm) light (∼10 mW/mm2) in a voltage-clamped neuron held at −70mV. Right, population data for n = 22 neurons. In this and subsequent figures, gray bars represent mean ± standard deviation unless otherwise indicated. Yellow bars in this and subsequent figures represent the period of yellow light exposure. (C) Kinetic properties of yellow light-elicited, Halo-mediated currents from voltage-clamped neurons. (i), 15–85% current onset time; (ii), 85–15% offset time. For each measurement, data is presented from neurons held at −70 mV, −30 mV and+10 mV (left to right). In this panel, gray bars represent mean ± standard error of the mean (S.E.M.). (D) Neuronal hyperpolarizations elicited by optical activation of Halo. Left, representative membrane voltage hyperpolarizations elicited by two 1-second pulses of yellow light, in a current-clamped neuron held at resting membrane potential. Right, population data for n = 19 neurons. (E) Kinetic properties of yellow light-elicited, Halo-mediated hyperpolarizations from current-clamped neurons, including both 15–85% voltage change onset time and 85–15% offset time.