CNR1 and major depressive disorder: However, when the impact of CB1R was tested more selectively using genetically modified mice with cell-specific receptor deficiency, unexpectedly, it was the ablation of the astroglial (Figure 1H; GFAP-CreERT2 × floxed CB1R), but not the neuronal CB1R that completely abolished THC-dependent depression (Figure 2A; Han et al., 2012).