Cluster analysis of anterogradely-labeled VGluT2-IR and CGRP-IR terminals in lamina I. The 3D center of mass coordinates were calculated for the Neurobiotin- and immuno-labeled terminals from 3D confocal data sets for medial, mid and lateral lamina I from one animal. The coordinates were analysed by hierarchical cluster analysis with SPSS. The data set shown here is from medial lamina I. A: Neurobiotin-labeled terminals with VGluT2-IR; B: Neurobiotin-labeled terminals with CGRP-IR; C: Neurobiotin-labeled terminals with both VGluT2-IR and CGRP-IR. Each statistically-determined cluster is assigned a different color. The red and dark green clusters at the dorsal edge of the field are dominated by VGluT2-IR terminals (ratio of VGluT2:CGRP terminals is about 2:1 in each cluster), whilst the orange and yellow clusters along the ventral edge of the field are dominated by CGRP-IR terminals (ratio of CGRP:VGluT2 terminals is about 2:1 in each cluster; X2 test and analysis of residuals, p < 0.05 in each case). The axes indicate the orientation of the data set: D; dorsal, V; ventral, M; medial, L; lateral. Scale bar in C represents 10 μm and applies to panels A-C. LT; Lissauer's Tract, I; lamina I, IIo; outer lamina II.