Fig. 5
Morphological classification of projection neurons in the mitral cell layer. a X–z-plane projection of all mitral cell layer projection neurons (MCLPNs, n = 45). X-axis approximately corresponding to posterior (P) → anterior (A) and Z-axis to dorsal (D) → ventral (V) direction. Triangles represent MCLPN midpoints of the five experiments. b Overlay of preferential MCLPN locations indicated as ellipsoid body around the respective midpoint based on SD of distances (n = 5). Magenta square indicates common MCLPN midpoint and dashed line denotes SD of the distances of all cells. c Based on two principal morphological parameters, MCLPNs were analyzed by fitting a two-component GMM. Probability density function (PDF) shown as discretized mesh (coloring as indicated). Black dots indicate individual cells, red dots their projections onto the 2D plane. Colored PDF isolines according to color bar. Histograms show frequencies of individual dimensions. d Consecutive assignment of cells to one of the two clusters (triangles: Cluster 1, MC or squares: Cluster 2, dTC). Coloring indicates posterior probability of each cell to be part of the MC cluster. Dashed line shows cutoff value of 200 µm2 soma area, the assumed lower limit for typical MCs. Cells of the MC group having a smaller soma size are individually marked by green dots. e Cell ranking according to “cluster membership score,” derived from posterior probabilities. f Cell numbers of the two subsets MC and dTC (n = 5, mean ± s.d.). g Comparison of x- and z-spreads per experiment between MCs and dTCs (two-sample t test, *p < 0.05, n.s. not significant). Mean ± s.d. indicated by blue circle and bar. h Ellipsoid body based on SDs of distances to common MC midpoint. The smaller inner ellipsoid (blue) around the common MC midpoint (red circle) is based on SD's of the distances from individual MC midpoints to the common MC midpoint. i Same for dTCs. Green circle illustrates the position of the glomerulus at the origin. Color code for data from different experiments as in Fig. 4b
