Antipsychotics improve Delta9-tetrahydrocannabinol-induced impairment of the prepulse inhibition of the startle reflex in mice.

Recently, cannabinoid receptor agonists have been reported to impair prepulse inhibition (PPI) of the startle reflex. In the current study, we examined the effect of Delta9-tetrahydrocannabinol (THC), the principal psychoactive component of cannabis, on the PPI, and found that THC (10 mg/kg, i.p.

Antagonistic effects of methanolic extract of Polygala telephioides on morphine responses in mice.

The present study was undertaken to investigate the antagonistic effects of the methanolic extract of Polygala telephioides (PT) on morphine responses in mice. Single administration of PT tended to antagonize the morphine-induced analgesia in a hot-plate test. Moreover, PT (300 mg/kg, p.

Anandamide inhibits the DOI-induced head-twitch response in mice.

Rationale: Recently, Delta(9)-tetrahydrocannabinol (THC), the major psychoactive component of marijuana, and synthetic cannabinoid receptor agonists reportedly reduced the head-twitches induced by the 5-HT(2A/2C) receptor agonist 1-(2,5-dimethoxy 4-iodophenyl)-2-amino propane (DOI) in mice, which is mediated via the activation of 5-HT(2A) receptor. However, the effect of endogenous cannabinoid anandamide on the head-twitch response has not been studied.

Objectives: In this study, we investigated the effect of anandamide on the DOI-induced head-twitch response in mice.