CB1R expression mapping in mPFC-vlPAG circuit

This component of the study used advanced molecular techniques to characterize CB1R expression patterns in the medial prefrontal cortex to ventrolateral periaqueductal gray circuit. The researchers employed viral tracing to map projections from mPFC CaMKIIα neurons to vlPAG, combined with immunohistochemistry and fluorescent in situ hybridization to visualize CB1R expression. RNAscope technique was used for high-resolution detection of CB1R mRNA in specific cell populations. The study aimed to identify sex differences in CB1R expression on CaMKIIα-expressing excitatory neurons in the mPFC and determine how these neurons project to and regulate GABAergic neurons in the vlPAG. This mapping was essential for understanding the anatomical substrate underlying sex-specific cannabinoid analgesia.