Figure 9.

Effects of cannabinoids on oICSS maintained by stimulation of medial VTA DA neurons. A, B, Systemic administration of Δ⁹-THC (1, 3 mg/kg, i.p., 15 min prior to testing) dose-dependently shifted the rate-frequency function curve downward in DAT-Cre mice (A), but not in DA-CB1-KO mice (B). C, D, Systemic administration of ACEA (1, 3 mg/kg, i.p., 15 min prior to testing) dose-dependently shifted the rate-frequency function curve downward in DAT-Cre (C), but not in DA-CB1-KO mice (D). E, F, Systemic administration of JWH133 (10, 20 mg/kg, i.p., 15 min prior to testing) dose-dependently shifted the rate-frequency function curve to the right in DAT-Cre (E) and DA-CB1-KO (B) mice. *p < 0.05, ***p < 0.001, compared with the vehicle control group.