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Fig. 3 | BMC Biology

Fig. 3

From: Optimized photo-stimulation of halorhodopsin for long-term neuronal inhibition

Fig. 3

488-nm light alone enables efficient and stable long-term photo-stimulation of eNpHR3.0. a Sample voltage-clamp recordings from a single cell illustrating the power-dependence of HR-mediated currents evoked by photo-stimulation at 594 nm (top) or 488 nm (bottom), delivered at 1 mW (left), 3 mW (middle), or 5 mW (right). Note that photo-currents evoked at 488 nm display lower peak amplitudes, but high temporal stability across the entire power range examined. At the end of each trial, 488-nm light (5 mW) was used to accelerate the recovery from inactivation (note the difference in onset kinetics of evoked currents depending on the degree of previous inactivation). Current responses to − 10-mV voltage steps used to monitor access resistance are clipped for clarity (#). bd Late (Ilate, b) and peak (Ipeak, c) current amplitudes as well as the ratio of Ilate versus Ipeak (d) normalized to the respective values at 594 nm and 1 mW (n = 7 cells). e Sample traces from a single cell photo-stimulated at 594 nm and/or 488 nm and a constant total light power of 5 mW. f Quantification of Ilate measured during the photo-stimulation regimes indicated normalized to Ilate obtained by photo-stimulation at 594 nm (5 mW) alone. Note that each combination of 594 nm plus 488 nm tested (at constant total power) considerably outperformed photo-stimulation at 594 nm alone (dotted line). Each symbol represents a single cell. Data are presented as mean ± SEM. **P < 0.01, ***P < 0.001

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