Fig. 9
Effect of withdrawal-associated environmental cues on the activity of mPFC projection neurons to the BLA. a Averaged CPA scores in saline + saline, saline + naloxone, chronic morphine + saline, and chronic morphine + naloxone groups (n = 6, **P < 0.01, compared to preconditioning test in chronic morphine + naloxone group). b Effect of withdrawal-associated environmental cues on the expression of c-Fos in mPFC projection neurons to the BLA. Up line: c-fos positive cells (red color) in the mPFC in saline + saline, saline + naloxone, chronic morphine + saline, or chronic morphine + naloxone group. Middle line: FG-labeled neurons (green colored) in the mPFC in saline + saline, saline + naloxone, chronic morphine + saline, or chronic morphine + naloxone groups. Bottom line: co-labeling of c-Fos and FG (yellow color) in the mPFC in saline + saline, saline + naloxone, morphine + saline, or morphine + naloxone groups. Scale bar, 500 μm. mPFC regions enclosed by white boxes were shown in a higher magnification in right square images; scale bar, 50 μm. c The average percentage of the co-labeled positive neurons with FG and c-Fos in the mPFC in saline + saline, saline + naloxone, chronic morphine + saline, or chronic morphine + naloxone groups. n = 6, *P < 0.05, compared to saline + saline group. Data are shown as the mean ± SEM