Fig. 5. Spatiotemporal relation of anoxic Ca_i rises in Purkinje neurons. Digital imaging was used to measure Ca_i in two regions of interest (pink, dendritic tree; red, soma). The continuous Ca_i traces illustrate that administration of CN^– (1 mmol l^–1) in the presence of tolbutamide (200 µmol l^–1) induces instantly a similar moderate Ca_i rise in both the soma and dendrites. During the following 60 s, a secondary progressive Ca_i increase occurs first in the dendritic tree. Subsequently, a Ca²⁺ wave progresses from the dendrites to the soma as shown by the sequence of individual images whose numbers correspond to those on the continous Ca_i trace. Data and images from K. Ballanyi et al.