Figure 2. Different discharge patterns expressed by embryonic inspiratory pacemaker neurons.
Patch-clamp recordings of individual pacemaker neurons from three different preparations expressing spontaneous plateau (A), oscillatory (B) or mixed plateau/oscillatory (C) burst firing patterns. (D) Histograms showing frequency distributions of the burst-generating dirve potential (DP) amplitude (D1–3, left column) and duration (D1–3, right column) for the three types of pacemaker neurons. D4: Histograms representing mean DP amplitude ± SEM (left) and mean DP duration ± SEM (right) for pacemaker neurons expressing plateau-like (blue bars), burst-like (red bars) or mixed (green bars; light green bars correspond to short-lasting and long-lasting bursts when grouped separately) activity. Asterisks indicate significant differences (Mann-Whitney test; p<0.001), while numbers of neurons analyzed for each pacemaker phenotype are indicated in the corresponding bar. (E) Distribution plot for DP duration vs DP amplitude measured for neurons recorded for 8 to 10 min (blue, plateau bursting pacemakers (n = 8); red, oscillatory bursting pacemakers (n = 5); green, mixed pacemakers (n = 5). Note that the latter expressed two types of burst duration/amplitude relationship that overlapped with either the purely plateau or oscillatory bursters.