Fig. 2.
Classification of cell type according to BKCa and IB4 immunostaining intensity. Measures of cell area and the fluorescence intensity of the BKCa and IB4 immunostaining from 24 tissue sections (Fig. 1) from a total of 4 ganglia yielded a database consisting of 1,448 separate neurons. An automated cluster analysis (see materials and methods) segregated these normalized data into 2 distinct populations presumably representing unmyelinated C-type (n = 1,390, blue dots) and myelinated A-type (n = 58, black dots) VGN. Spheroids centered at the intersection of the population means for each of the 3 measures are drawn with a radii equal to 2 SD. Lack of overlap is evidence that the 2 populations are distinct and statistically unique (P < 0.05). Population data and additional statistical analyses are also presented in results. Red arrows indicate trending of the data toward an ideal A-type VGN, one with larger diameter but low intensity IB4 and BKCa fluorescence, or an ideal C-type VGN, one with smaller diameter and high intensity IB4 and BKCa fluorescence.