Appendix 1—figure 2. Drosophila R1-R6 photoreceptor membrane’s electrical circuit (HH-model).

A photoreceptor’s membrane potential, V_m, is the difference between the negative inside (intracellular) and positive outside (extracellular) voltages. V_m can be calculated, using Hodgkin-Huxley formalism, whereupon, a photoreceptor membrane is modelled as a capacitor, C_m, voltage-gated channels as voltage-regulated conductances, g, leak channels as fixed conductances, reversal potentials for different ion species as DC-batteries. Abbreviations: I_ksh: Shaker; I_dr, delayed rectifier; I_novel, novel K⁺; K_leak: K⁺ leak; I_cl, chloride leak currents. The used deterministic Drosophila photoreceptor HH-model is adapted from (Niven et al., 2003; Vahasoyrinki et al., 2006).