Figure 7.

Quantitative PCR demonstrates a gene expression profile in β-gal-positive neurons from sensitized cocaine-challenged rats different from that of β-gal-negative neurons from the same rats, or of all neurons from saline-challenged rats. a, mRNA levels for the immediate early genes arc, fosB, and nr4a3 are increased in β-gal-positive neurons. b, mRNA levels for the D₁-type cell marker prodynorphin (pdyn) are increased in β-gal-positive neurons, while the D₂ receptor drd2 is decreased in β-gal-positive neurons. c, mRNA levels for the kinase that activates p38 MAPK (map2k6) are decreased in β-gal-positive neurons, while mRNA levels for the phosphatase that inactivates p38 MAPK (mkp1 or dusp1) are increased in β-gal-positive neurons. n = 3 for every sample. See Table 3 for p values. *p < 0.05 versus NeuN-positive neurons from saline-injected rats. ^†p < 0.05 versus β-gal-negative neurons from cocaine-injected rats.