Figure 2.

Heat activates single-channel currents in rat dorsal root ganglion neurons. Cell-attached patch recordings were performed with the electrode voltage clamped at 0 mV. No single-channel activity was observed at 22°C. Upon heating the bath, brief single-channel inward currents began to appear at approximately 29°C. At 37°C, channel openings became more frequent and longer in duration. At 39°C, openings of a second heat-activated channel became more frequent. Both heat-activated single-channel currents in this patch exhibited a similar amplitude of approximately 2 pA. If a resting potential of −60 mV is assumed, this would reflect a single-channel conductance of 33 pS. Finally, subsequent cooling of the bath to 22°C caused single-channel activity to cease.