Figure 8
Low [Ca2+] o antagonizes the effects of NE. In panel a, the arrow points to the superimposition of the small deflection on the previous AP. NE was administered between the downward arrows. In panel e, the control trace labeled with a square was superimposed on the trace marked by a star. [Ca2+]o was decreased as indicated (panes f-h). In panel g, the ThVos that missed the threshold is labeled with a rhombus and the following AP has been superimposed on it (arrow) in the bottom trace recorded at higher gain. In panel h, the trace labeled by a star is the same trace labeled with the same symbol in panel e. Panel i was recorded in the presence of NE during recovery from low [Ca2+]o.