Fig. 3.

Changes in mRNA levels of mMOR-1 splice variants after 6 wk of morphine administration in whole brain and brain regions. The levels of the full-length variants following morphine administration were determined as described in Methods, and the changes were normalized to saline levels. The changes on the y axis are presented on a log scale to accommodate the wide range of differences among the variants and among the regions. Values of 1 correspond to no change from saline controls. Values less than 1 (within the gray zone) correspond to decreases, whereas values greater than 1 represent increases. Significance was determined by ANOVA with Bonferroni’s multiple comparison test.