Figure 6
Suppression of synaptically evoked spikes by iChloC.
(A) Schema of targeted cell-attached recordings from transfected CA1 pyramidal cells in an organotypic hippocampal slice culture. Drawing by J.S. Wiegert & T.G. Oertner. (B) Postsynaptic spikes were induced by electrical stimulation of afferents in stratum radiatum (4 μA, 0.5 ms). Upper trace: electrical stimulation, only. Middle trace: a blue light pulse (0.1 mW/mm2, 5 ms) delivered through the water immersion objective prevented spike initiation after synaptic stimulation. Lower trace: a spike was triggered again by electrical stimulation alone. (C) Raster plot of spike timing after synaptic stimulation of iChloC expressing neuron. Light pulse reliably blocked synaptically evoked spikes (trials #11–20). (D) Summary of synaptic stimulation experiments. While slowChloC activation had no significant effect on electrical spike induction (n = 5 slices cultures), iChloC activation blocked spiking in the majority of neurons (n = 7 slice cultures). Spike inhibition was fully reversible in all experiments.
