Figure 2. Neurons are the major contributors to de novo neurosteroid biosynthesis.

(A) Expression of Cyp11a1 from single cells visualized in a cell type defined t-SNE plot with colors that indicate zero and positives (as four quartile ranges). Valuation of regional and cell type specific Cyp11a1 expression (heatmap with total expression log₂CPM) and percentage of cell type-specific expression as indicators of pregnenolone production indicates that majority of de novo neurosteroidogenesis occurs in different types of glutamatergic and GABAergic neurons. The glutamatergic IT-ET neurons showed the highest levels of Cyp11a1 expression, followed by NP-CT-L6b neurons. (B) Expression of Star from single cells visualized in a cell type defined t-SNE plot (color range indicates quartiles) and heatmap. Valuation of regional and cell type specific Star as an essential step in steroidogenesis indicates a pattern inconsistent with Cyp11a1, encompassing both neuronal and non-neuronal cells. (C) A t-SNE plot visualizing co-expression of Cyp11a1 and Star (Red), highlights the frequency of co-expression correlated to the different neuronal cell populations.