Fig 3. Gain modulation in stellate cells.

(A) Layer 2 hippocampal stellate cell morphology, reproduced from model of reconstructed cell [32, 33]; (B) (top) Membrane voltage for net photocurrent as xNpHR is varied for an irradiance of 0.07 mW/mm². Current injection was fixed at a location on a dendrite more than 100μm from the soma. (bottom) Voltage traces, recorded at soma, for I_dend = 1.2 nA respectively, following current injection while ChR2 and NpHR are photoactivated (bars indicate optical activation and relative strengths of opsin strengths); (C) IF curves for current injection indicates divisive gain modulation; (D) Voltage traces after driving the neuron with multiple presynaptic EPSP and IPSP events spread throughout the dendrites, with photoactivation dominated by ChR2 and NpHR respectively; (E) IF curves for in vivo-like input reveal no gain modulation (taken from multiple independent realizations for presynaptic spiketimes, n = 5).