Jpn. J. Pharmacol. 78 (1), 105-108 (1998)

Vulnerability of Synaptic Plasticity in the Striatum of Methamphetamine-Sensitized Rats

Ikumi Arai (1), Takao Shimazoe (1,*), Akiko Yoshimatsu (1), Hirotaka Inoue (1), Shigenobu Shibata (2) and Shigenori Watanabe (1)

(1) Department of Pharmacology, Faculty of Pharmaceutical Sciences, Kyushu University 62, Fukuoka 812-8582, Japan
(2) Department of Pharmacology, School of Human Sciences, Waseda University, Tokorozawa, Saitama 359-1164, Japan
(*) To whom correspondence should be addressed.

Abstract: We examined the influence of ischemia on methamphetamine (MAP)-induced behavioral sensitization and enhancement of dopamine (DA) release. After the recovery period of the ischemia operation, rats were treated with MAP (1 mg/kg, i.p.) once daily for 6 consecutive days. Re-administration of MAP (0.5 mg/kg, i.p.) potentiated the increase of locomotor activity after a 3-day withdrawal and the enhancement of DA release from striatal slices after a 6-day withdrawal. The MAP-induced sensitization was impaired by 5 min ischemia. On the other hand, the increase of locomotor activity induced by single MAP (1 mg/kg, i.p.) administration was impaired by 20 min of ischemia. Moreover, in saline-treated rats the increase of DA release from striatal slices induced by MAP (10 microM) application was also impaired by 20 min of ischemia. These results indicate that the neuronal plastic change may be very vulnerable to ischemia in MAP-induced sensitization.

Keywords: Methamphetamine, Ischemia, Sensitization

Copyrightę The Japanese Pharmacological Society 1998

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