L-type voltage-dependent calcium channels in the ventromedial orbitofrontal and prefrontal cortices mediate the inhibitory effects of (S)-ketamine but not (R)-ketamine on marble burying in male mice
European Journal of Pharmacology October 25, 2025 Satoshi Deyama, Kenji Mishiro, Munetaka Kunishima et al.
A single injection of (R)-ketamine at 30 mg/kg, but not 10 mg/kg, reduced marble burying—a measure of compulsive-like behavior—in male mice at 2 hours, 24 hours, and 7 days after treatment, without affecting general movement. (S)-ketamine at 10 mg/kg also reduced burying. Blocking L-type voltage-dependent calcium channels (L-VDCCs) with verapamil prevented the effect of (S)-ketamine but not of (R)-ketamine. Infusing verapamil directly into the ventromedial orbitofrontal cortex or ventromedial prefrontal cortex also blocked (S)-ketamine's effect. These findings suggest (R)-ketamine produces anticompulsive-like effects comparable to a 3-fold lower dose of (S)-ketamine, and that L-VDCC activation in those brain regions mediates the effects of (S)-ketamine but not (R)-ketamine.