Figure 2.
CGRP enhances the excitability of sensory neuron soma. (a) Voltage responses of a dissociated DRG neuron to ramp currents under control conditions, 3 min in 100 nM CGRP, and following 5 min of washout. Traces are vertically displaced by 20 mV for visual clarity. Note the ramp threshold (red dot) for each set of traces. A 0.5 nA step current preceded each ramp to monitor membrane resistance. (b) Firing of a neuron is induced by 300 nM CGRP (gray bar) which is suppressed by the CGRP receptor antagonist, CGRP8-37 (black bars). This neuron, as most observed, was capsaicin sensitive (red bar).