Figure 4.

Cluster analysis of V3 neurons based on electrophysiological properties. A, The first eigenvector of four attributes (f–I slope, C_m, first spike frequency, and sag amplitude at −120 mV) that produced the best criterion. B, Histogram of PC1 exhibits two well defined modes corresponding to positive and negative values representing cluster 1 (PC1 <0, light gray) and cluster 2 (PC1 >0, dark gray). Ci–iv, Histogram of distribution of the four main attributes (A) with cells in cluster 1 (light gray) and cluster 2 (dark gray).