Figure 4.
Spatial distribution of near-threshold EPSP signals and associated Ca2+ transients derived from combined Vm and Ca2+ measurements from thin terminal dendritic branches of the glomerular tuft of a mitral cell. A, The fluorescent image of the glomerular tuft in recording position. B, EPSP-related Vm signals from multiple locations as indicated in the bottom frame in A. C, EPSP-driven Ca2+ signals from the same locations (superimposed black trace are normalized to AP-related calcium signals). D, AP-driven Ca2+ signals from the same locations. E, Trace display of the Vm signal. F, The EPSP signal shown as a temporal sequence of color-coded spatial maps determined at four time points indicated by arrows in E. The peak of the Vm signal was reached uniformly throughout the tuft within 4 ms. G, Trace display of the Ca2+ signal. H, The spatial characteristics of the Ca2+ response shown as a temporal sequence of color-coded spatial maps determined at four time points indicated by arrows in G.