Calcium current basal facilitation is elevated in SCG neurons expressing mGluR7. A. Sample calcium current traces from a control cell (upper) and an mGluR7 expressing cell (lower) obtained using the triple-pulse voltage protocol (shown in center). Each current trace was obtained in the absence of any receptor agonist. Note that the post/pre ratio is elevated in the mGluR7 expressing SCG neuron, reflecting the higher basal facilitation levels in those cells. B, Average (± SEM) basal facilitation, and values from individual cells, illustrating the facilitation values from SCG neurons expressing mGluR4 (°), mGluR7 (□), mGluR4 and 7 together (♢), and in control SCG neurons (✕); uninjected and expressing other mGluRs recorded on separate days from the cells in the other groups). Total number of cells in each group is shown in parentheses. C, L-AP4 concentration-response curve from mGluR7 expressing SCG neurons expressed as facilitation (post/pre) values. Solid line represents a fit to the Hill equation, with baseline fixed at 1.5. Fits to free parameters are as indicated (inset).