Fig. 4

Multiple morphological types of CRH neurons form putative connections in the mPFC. A Overview of reconstructed CRH neurons including somata (indicated by the purple bodies) and fibers (indicated by the colored lines) from layers 1–4 in a column with a volume of 350 × 500 × 500 μm in a PrL subregion within the mPFC. B Representation of 67 reconstructed somata and dendrites of CRH neurons arranged along their somatic depths with respect to the pial surface; the pie chart at the bottom right shows the percentages of neurons distributed at different somatic depths. C Upper half: Correlation between total dendritic length and somatic depth in PrL neurons (Pearson’s correlation coefficient r = 0.51, P < 0.0001); Lower half: Correlation between total Euclidean distance and somatic depth in PrL neurons (Pearson’s correlation coefficient r = 0.59, P < 0.0001). D Sholl analysis of the dendrites of neurons with somatic depths = 50–100 μm and 100–150 μm illustrating changes in the mean number of intersections with increasing radial distance from the soma. Inset images show exemplary intersections on two typical neurons (left: somatic depth = 50–100 μm, right: somatic depth = 100–150 μm) with different somatic depths, n = 15 cells for somatic depths = 50–100 μm and 19 cells for somatic depths = 100–150 μm. E Left: The total dendritic length of CRH neurons with somatic depths < 100 μm showed differences compared with those with somatic depths = 100–150 μm (one-way ANOVA, multiple comparisons, P = 0.0285) and soma depths > 150 μm (one-way ANOVA, multiple comparisons, P = 0.0005). Right: The total Euclidean distance of CRH neurons with a somatic depth of < 100 μm showed differences compared with those with soma depths = 100–150 μm (one-way ANOVA, multiple comparisons, P = 0.0213) and somatic depths > 150 μm (one-way ANOVA, multiple comparisons, P = 0.0001), n = 13 cells for somatic depths < 100 μm, 21 cells for 100–150 μm and 31 cells for > 150 μm. F–H Three types of connections between CRH neurons in the mPFC. F a (reconstructed neurons) and b (original image) show the type-I connection (the connection site is indicated by the purple arrowhead in the red dotted box). G The yellow-dotted boxes in c (reconstructed neurons) and d (original image) show the type-II connection (red arrowheads indicate a branch of basal dendrites of one neuron and the orange arrowhead indicates the cell body of another neuron; the connection site is indicated by the purple arrowhead). Green-dotted squares in c (reconstructed neurons) and e (original image) showed the type-III connection (red arrowheads indicated a branch of basal dendrites of one neuron and the orange arrowheads indicate a branch of basal dendrites of another neuron; the connection site is indicated by the purple arrowhead). H Green-dotted squares in f (reconstructed neurons) and g (original image) also showed the type-III connection (yellow arrowheads indicate a branch of basal dendrites of one neuron and the blue arrowheads indicate a branch of basal dendrites of another neuron; the connection site is indicated by the purple arrowhead)