Figure 1.

ASIC currents in CA1 PNs and defined interneurons. A, Voltage responses to 1 s depolarizing (+600 pA) or hyperpolarizing (−300 pA) current pulses in the whole-cell current-clamp configuration from an O-LM cell, a PN and a BC, respectively. B, Two-photon z stack projection of neurons in A filled with biocytin and stained with FITC-conjugated avidin. Note that the O-LM cell has its axonal arborization in stratum lacunosum moleculare (SLM), whereas the BC's axon is largely restricted to the granule cell layer (GCL). SR, stratum radiatum; SP, stratum pyramidale; SO, stratum oriens; ML, molecular layer. C, Inward currents recorded at −60 mV after rapid pH changes from pH 7.4 to 5 in nucleated patches from an O-LM cell, a PN and a BC, respectively. Traces are averages of 5–10 sweeps. H⁺-evoked currents are reversibly blocked by 10 μm amiloride (control: black; amiloride: gray; washout: red). Inset, Schematic of the experimental configuration. The open tip response was 227 ± 50 μs (n = 3) (see Materials and Methods). D, Scatter plots showing that the current amplitude (left) and density (right) of O-LM cells are significantly larger than those of PNs and BCs. ***p < 0.0005.