Figure 4
Photocurrent reversal potential vs. GABA receptor reversal potential.
(A) Current traces of CA1 pyramidal cell expressing iChloC. Photocurrent reversal (left) is close to the reversal potential of GABAA receptor mediated IPSCs (right), indicating pure Cl− conductance. (B) I-E curves for iChloC photocurrents and IPSCs. (C) Current traces of CA1 pyramidal cell expressing slowChloC. The photocurrent (left) reverses more positive than GABAA receptor mediated IPSCs (right), indicating mixed ionic conductance of slowChloC. (D) I-E curves for slowChloC photocurrents and IPSCs. (E) No systematic difference in GABAA reversal between slowChloC and iChloC neurons. Between individual neurons, GABAA reversal and iChloC reversal were highly correlated (r2 = 0.67), indicating that the same ions are conducted. SlowChloC photocurrents were not correlated with GABAA reversal potential (r2 = 0.04). (F) Light stimulation experiments under current clamp conditions (I = 0) show significantly smaller depolarization from resting membrane potential in iChloC expressing neurons (n = 8) compared to slowChloC expressing neurons (n = 10).
