Fig. 1
From: Optimized photo-stimulation of halorhodopsin for long-term neuronal inhibition
Blue light accelerates the recovery of eNpHR3.0-mediated currents from inactivation in a duration- and power-dependent manner. a Sample voltage-clamp recording illustrating that prolonged (10 s) photo-stimulation at 594 nm (5 mW) induces pronounced inactivation of eNpHR3.0-mediated currents. Note that the recovery from inactivation is slow (test pulse at Δt = 15 s). b Sample trace from another cell demonstrating that blue light (500 ms, 488 nm, 5 mW) accelerates the recovery from inactivation. Also note the outward current induced by blue light. c Recovery of eNpHR3.0-mediated currents is enhanced by blue light. Inset, recovery is defined as the ratio of current amplitudes induced by the test (at Δt) versus initial pulse, measured relative to Ilate (i.e., recovery = A2/A1). Dotted lines represent mono-exponential fits to population data. Each cell was tested for all values of Δt either without (Control, n = 7 cells) or with (Rescue, n = 8 cells) an intervening photo-stimulation at 488 nm (500 ms). In a and b, current responses to − 10-mV voltage steps used to monitor access resistance are clipped for clarity (#). d Independent of the degree of inactivation (1 − Ilate/Ipeak), time constants of recovery are lower for rescue as compared to control trials. Each symbol represents a single cell. e Recovery from inactivation depends on the duration of the 488-nm rescue pulse (blue lines). All traces are from a single cell. f Quantification. g Recovery from inactivation depends on the power of the 488-nm rescue pulse at a constant duration of 1 s. All traces are from a single cell. h Quantification. Data are presented as mean ± SEM