Psychopharmacology
February 2012
Nobuaki Egashira, Naomi Manome, Kenichi Mishima et al.
Cannabis is a widely used illicit substance. ∆(9)-Tetrahydrocannabinol (THC), the major psychoactive component of cannabis, is known to induce cognitive deficits that closely resemble the impairment observed in schizophrenic patients. We previously reported that THC (6 mg/kg) impairs spatial memory in the eight-arm radial maze, and that this memory disturbance was reversed by the cannabinoid...
Neuroscience
January 24, 2008
K Sano, K Mishima, E Koushi et al.
Delta(9)-tetrahydrocannabinol (THC) has been reported to induce catalepsy-like immobilization, but the mechanism underlying this effect remains unclear. In the present study, in order to fully understand the neural circuits involved, we determined the brain sites involved in the immobilization effect in rats. THC dose-dependently induced catalepsy-like immobilization. THC-induced catalepsy-like...
Life Sciences
December 20, 2002
Kenichi Mishima, Nobuaki Egashira, Yoshiaki Matsumoto et al.
To clarify the mechanism by which Delta9-tetrahydrocannabinol, a major psychoactive component of marijuana, impairs spatial memory in the 8-arm radial maze in rats via the cholinergic system, we used two acetylcholinesterase inhibitors, physostigmine and tetrahydroaminoacridine. Moreover, we examined the effect of Delta9-tetrahydrocannabinol on acetylcholine release in the frontal cortex and...
Brain Research
October 18, 2002
Nobuaki Egashira, Kenichi Mishima, Katsunori Iwasaki et al.
The purpose of this study was to identify brain sites that contribute to the delta(9)-tetrahydrocannabinol (delta(9)-THC)-induced impairment of spatial memory in rats. Rats were tested in the eight-arm radial maze after microinjections of delta(9)-THC into one of 14 different brain regions. The bilateral microinjection of delta(9)-THC (20 microg/side) impaired spatial memory when injected into...
European Journal of Pharmacology
June 12, 2002
Nobuaki Egashira, Kenichi Mishima, Shutaro Katsurabayashi et al.
The present study investigated the involvement of the serotonin (5-hydroxytryptamine, 5-HT) neuronal system in the Delta(9)-tetrahydrocannabinol-induced impairment of spatial memory in the eight-arm radial maze in rats. Delta(9)-Tetrahydrocannabinol (6 mg/kg, i.p.), which impairs spatial memory, significantly increased the 5-HT content in the ventral hippocampus. A microdialysis study showed...
Journal of Pharmacobio-Dynamics
1981
Kazuko Kawanishi, Yôhei Hashimoto, Michihiro Fujiwara et al.
11 citations
Harmine, a hallucinogen with potent monoamine oxidase inhibitory properties, induced abnormal behavior, including tremor, scratching, head twitch and cage biting, in the mouse. A dose-dependent tremor was produced by all routes of administration of harmine. Although oxotremorine tremor was markedly suppressed by atropine, harmine tremor was unaffected by cholinergic drugs, remarkably inhibited...