Modeling Migraine Chronification and its Relief; the Effects of THC on Recurrent NTG-Induced Migraine Endpoints in Rats

This study investigated the analgesic effects of a THC pro-drug in a rodent model of recurrent migraine. Rats received 4 nitroglycerin-induced (NTG: 10mg/kg/2ml) migraine episodes every third day for 12 days; saline, cremaphor-vehicle, propranolol (10mg/kg/ml), or THC-VAL-HS (0.5, 1.0, and 2.0 mg/kg/ml) were given IP 30 minutes before NTG. Behavioral endpoints of photosensitivity, activity, orbital tightening, and tactile allodynia were assessed 110 m after NTG. Migraine severity increased over the course of the four episodes, pointing toward chronification and an important step in model validation. However, neither propranolol nor THC-VAL-HS significantly attenuated any of the migraine-related endpoints. These data are in contrast with clinical reports that marijuana mitigates migraine severity. These findings suggest that higher doses of THC-VAL-HS and/or other cannabinoid constituents in marijuana may be responsible for such anecdotal anti-migraine activity of cannabis