Fig. 6.

Representative EFS-evoked [Ca²⁺]_i transients in an isolated normoxic fetal SCG cell (A) and LTH fetal SCG cell (B) in the absence and presence of the sarco(endo)plasmic reticulum Ca²⁺-ATPase antagonist cyclopiazonic acid (CPA). Two to three supramaximal EFS trains (5 Hz, 50 pulses, 300 mA; see materials and methods, protocol 3) were applied in the absence (control) and presence of 10 μM CPA. The initial [Ca²⁺]_i rise induced by the presence of CPA was allowed to return back to baseline [Ca²⁺]_i before EFS was repeated. The time constant for recovery (τ) was obtained for all [Ca²⁺]_i transients as a first-order exponential decay fit from the peak [Ca²⁺]_i to 95% of basal [Ca²⁺]_i.