Fig. 7.

β-Receptor activation hastens evoked ET cell bursting. A: a slow current ramp (10 pA/s, shown at bottom from a holding potential of approximately −65 mV) was applied to evoke burst in ET cells before and during Isop (10 μM) application in the presence of APV-CNQX-gabazine. Isop shortens the delay to the 1st burst and increases the slope from ramp onset. Note that cell was hyperpolarized to −65 mV using injected current to stop spontaneous firing burst, and the membrane was depolarized and no additionally injected current was used during application of Isop. To better show the change of slope, the traces for Isop and control are superimposed. B: group data (n = 7 ET cells) show that Isop significantly shortens the delay to the 1st burst and increases the slope from ramp onset to the burst depolarizing envelope onset. *P < 0.01 vs. Control, paired t-tests.