title: Methamphetamine modifies the photic entraining responses in the rodent suprachiasmatic nucleus via serotonin release.
abstract: We examined whether methamphetamine modifies the photic entraining responses in the rat suprachiasmatic nucleus. Optic nerve stimulation increased vasoactive intestinal polypeptide release from rat suprachiasmatic nucleus slices, and methamphetamine inhibited this increase in a concentration-dependent manner. Optic nerve stimulation has been reported to evoke field potentials in rat suprachiasmatic nucleus slices. Methamphetamine attenuated this field potential, and maximal inhibition (75.5%) was achieved at a concentration of 100 microM. Systemic administration of methamphetamine (1-5 mg/kg) inhibited light (300 lux, 1h)-induced Fos expression in the suprachiasmatic nucleus; methamphetamine at a dose of 5 mg/kg, i.p. caused 40% inhibition of light-induced Fos expression. We examined whether the inhibitory effect of methamphetamine on photic entraining responses mediates serotonin release from the suprachiasmatic nucleus. High-performance liquid chromatographic analysis revealed that methamphetamine application increased serotonin release from rat suprachiasmatic nucleus slices in a concentration-dependent manner, but did not affect noradrenaline release. In addition, reduction of serotonin content attenuated the effect of methamphetamine on field potential induced by optic nerve stimulation in vitro and also light-induced phase advances of wheel running activity rhythm in vivo. The present results support the idea that methamphetamine produces an inhibitory effect on photic entrainment in the suprachiasmatic nucleus via serotonin release.
authors.affiliation: Department of Pharmacology, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ono
authors.forename: A
authors.initials: A
authors.lastname: Watanabe
authors.forename: Y
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: T
authors.initials: T
authors.lastname: Fukushima
authors.forename: Y
authors.initials: Y
authors.lastname: Nishikawa
authors.forename: T
authors.initials: T
authors.lastname: Moriya
authors.forename: S
authors.initials: S
authors.lastname: Shibata
authors.forename: S
authors.initials: S
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D001596:Benzylamines / Q000494:pharmacology; D015306:Biogenic Monoamines / Q000378:metabolism; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D002940:Circadian Rhythm / Q000187:drug effects*; D006224:Cricetinae; D010134:Fenclonine / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008647:Mesocricetus; D008694:Methamphetamine / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D014179:Neurotransmitter Uptake Inhibitors / Q000494:pharmacology; D009900:Optic Nerve / Q000187:drug effects / Q000502:physiology; D010775:Photic Stimulation; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism*; D018490:Serotonin Agents / Q000494:pharmacology; D013493:Suprachiasmatic Nucleus / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism
chemical_list: D001596:Benzylamines; D015306:Biogenic Monoamines; D000697:Central Nervous System Stimulants; D014179:Neurotransmitter Uptake Inhibitors; D016760:Proto-Oncogene Proteins c-fos; D018490:Serotonin Agents; D012701:Serotonin; D014660:Vasoactive Intestinal Peptide; D008694:Methamphetamine; C012102:DSP 4; D010134:Fenclonine