Fig. 3.

A: histograms showing proportion of occurrences of a given action potential cluster associated with single or multiple firings in pregnant (white bars) and nonpregnant (black bars) women at rest. No differences in firing occurrence were found between groups. When a cluster was present within a burst of activity, the majority of these occurrences (~60%) was associated with only a single action potential. The occurrence of multiple firings from a given cluster was relatively low, with clusters contributing 2 action potentials ~23% of the time, 3 action potentials ~8% of the time, and 4+ action potentials ~9% of the time. B: during the cold pressor test (CPT), there was a reduction in the occurrence of multiple firings and an increase in a singular event. This was consistent between pregnant (n = 10) and nonpregnant women (n = 13). *Significant change in the percentage of occurrences during CPT, P < 0.01.