Table 2. The effects of exposure to chronic, unpredictable stress (CUS) and/or concurrent treatment with the antidepressant imipramine (IMI; 10 mg/kg) on the dissociation constant (Kd) of 3H-CP55940 from the cannabinoid CB1 receptor.
Exposure of male rats to CUS for 21 days resulted in a significant reduction in the binding affinity (Kd) of the cannabinoid CB1 receptor in the hypothalamus, and this effect was prevented by concurrent IMI treatment. IMI treatment for 21 days reduced the Kd of the CB1 receptor in the prefrontal cortex and the ventral striatum. Significant differences from non-stressed (CON), vehicle (VEH) treated animals (p < 0.05) denoted by *. For all treatment conditions, n = 4–5. Data are presented as mean nM of 3H-CP55940 +/− SEM.
| CON/VEH | CUS/VEH | CON/IMI | CUS/IMI | |
|---|---|---|---|---|
| Prefrontal Cortex | 0.61 +/− 0.14 | 0.83 +/− 0.10 | 0.38 +/− 0.15* | 0.52 +/− 0.08 |
| Hippocampus | 0.60 +/− 0.11 | 0.59 +/− 0.11 | 0.79 +/− 0.15 | 0.55 +/− 0.06 |
| Hypothalamus | 1.54 +/− 0.15 | 0.57 +/− 0.07* | 1.02 +/− 0.06 | 1.22 +/− 0.45 |
| Ventral Striatum | 0.65 +/− 0.08 | 0.55 +/− 0.12 | 0.34 +/− 0.05* | 0.37 +/− 0.02* |
| Amygdala | 0.56 +/− 0.06 | 0.56 +/− 0.03 | 0.95 +/− 0.19 | 0.49 +/− 0.12 |
| Midbrain | 0.40 +/− 0.08 | 0.25 +/− 0.05 | 0.25 +/− 0.04 | 0.27 +/− 0.04 |