Presence of <i>CB2</i> gene in the brain.

<p>A, Relative brain expression of <i>CB2</i> gene in C57BL/6J and BALBc strains subjected to stress. <i>B</i>, Relative <i>CB2</i> gene expression levels in the striatum, midbrain, and hippocampus of C57Bl/6J mice. <i>C</i>, Mouse whole brain relative <i>CB2</i> gene expression levels following chronic treatment with heroin and cocaine. <i>D</i>, relative <i>CB2</i> gene expression levels in striatum and midbrain of mice that developed alcohol preference. <i>CB2</i> gene expression was relative to the standard laboratory brain obtained from C57BL/6J that was set to 1.0. The positive control was from the spleen and no cDNA in TaqMan PCR reaction served as negative controls.