In order to understand the underlying mechanisms responsible for the behaviors mediated by dextromethorphan (DM), we examined the effects of DM on locomotor activity and locomotor patterns in mice, and Fos-related antigen immunoreactivity (FRA-IR) of mouse brain following repeated administration of cocaine. Combined treatments (30 min prior to each cocaine administration) with DM dose-dependently decreased locomotor activity for high doses of cocaine (20 mg/kg, i.p./day × 7). DM combinations did not significantly affect hyperactivity for 10 mg cocaine/kg, i.p./day × 7. In contrast, combined treatments with DM increased the locomotor activity for 5 mg cocaine/kg, i.p./day × 7. These results were consistent with alterations in marginal activity. Repeated administration with cocaine or DM increased FRA-IR in the nucleus accumbens (NAc) and striatum which lasted for at least 7 days. Our results suggest that DM exhibits biphasic effects on the locomotor stimulation induced by cocaine, and that locomotor activities are in parallel with FRA-IR of the striatal complex. However, the role of FRA-IR regulated by DM or/and cocaine remains to be further determined.
|Number of pages||10|
|State||Published - Jun 29 2001|
Bibliographical noteFunding Information:
This study was supported by BK project and a grant (# HMP-99-N-02-0003) of the Good Health Research and Development Project (1999) of the Ministry of Health and Welfare, Republic of Korea. We thank Drs. J.S. Hong and M.J. Iadarola for donating antiserum against FRA.
Copyright 2007 Elsevier B.V., All rights reserved.
- Fos-related antigen protein
- Locomotor activity
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology (all)
- Pharmacology, Toxicology and Pharmaceutics (all)