Fig. 1.

CB₁R localization in the developing brain. (A–G) In situ hybridization demonstrating the spatial and temporal distribution of CB₁R mRNA in the mouse brain. Arrows in C and E and G denote CB₁R mRNA hybridization signal in pyramidal cells and SVZ progenitors, respectively. (H and I) Distribution of CB₁R mRNA in human fetal brain. Nissl/AChE histochemistry reveals territorial boundaries. (J–M) DAGLβ and CB₁R expression in mouse VZ/SVZ. Cortical Tbr2⁺ projection neurons migrating toward the CP express CB₁Rs. (N–R) CB₁Rs are selectively enriched in axons of cortical projection neurons. Arrows indicate corticothalamic axons, and arrowheads identify axons committed to the fibria. (Scale bars: E–G and K–M, 30 μm; N–R, 85 μm; A–D, H, and I, 100 μm.) See SI Text for abbreviations.