title: Extremely low-frequency electromagnetic field exposure during chronic morphine treatment strengthens downregulation of dopamine D2 receptors in rat dorsal hippocampus after morphine withdrawal.
abstract: The aim of this study was to investigate the effect of extremely low-frequency electromagnetic field (ELF-EMF) exposure during morphine treatment on dopamine D2 receptor (D2R) density in the rat dorsal hippocampus following withdrawal. Rats were exposed to ELF-EMF (20 Hz, 14 mT) or sham exposed for 1h per day before injection of morphine (10mg/kg, i.p.) once daily for 12 days. The saline control group was sham exposed for the same period. Immunohistochemistry was used to detect the density of D2Rs on the 1st, 3rd and 5th morphine withdrawal days. The results showed that the density of D2Rs in sham-exposed morphine-treated rats on the 1st and 3rd days of morphine withdrawal was significantly lower than that of the saline control group. The ELF-EMF-exposed morphine group also exhibited a significantly lower density of D2Rs on the 1st and 3rd withdrawal days relative to the sham-exposed morphine group. However, the D2R density in both groups tended to recover as morphine withdrawal days increased. The results suggest that dorsal hippocampal D2Rs are sensitive to morphine withdrawal and that this is potentiated by ELF-EMF pre-exposure during morphine treatment.
authors.affiliation: Laboratory of Primate Neuroscience Research and Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, #32 Jiao Chang Dong Lu, Kunming, Yunnan, 650223, PR China.
authors.forename: Xiusong
authors.initials: X
authors.lastname: Wang
authors.forename: Yadong
authors.initials: Y
authors.lastname: Liu
authors.forename: Yanlin
authors.initials: Y
authors.lastname: Lei
authors.forename: Dongming
authors.initials: D
authors.lastname: Zhou
authors.forename: Yu
authors.initials: Y
authors.lastname: Fu
authors.forename: Yi
authors.initials: Y
authors.lastname: Che
authors.forename: Ruchang
authors.initials: R
authors.lastname: Xu
authors.forename: Hualin
authors.initials: H
authors.lastname: Yu
authors.forename: Xintian
authors.initials: X
authors.lastname: Hu
authors.forename: Yuanye
authors.initials: Y
authors.lastname: Ma
mesh_terms: D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D004298:Dopamine / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D004334:Drug Administration Schedule; D004574:Electromagnetic Fields; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D007150:Immunohistochemistry; D008297:Male; D009020:Morphine / Q000494:pharmacology; D009021:Morphine Dependence / Q000378:metabolism / Q000503:physiopathology*; D009294:Narcotics / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017448:Receptors, Dopamine D2 / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D013375:Substance Withdrawal Syndrome / Q000378:metabolism / Q000503:physiopathology*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects
chemical_list: D009294:Narcotics; D017448:Receptors, Dopamine D2; D009020:Morphine; D004298:Dopamine