title: MK-801 changes the role of glutamic acid on modulation of algesia in nucleus accumbens.
abstract: Dizocilpine maleate (MK-801) causes the blockage of the glutamic acid (Glu) receptors in the central nervous system that are involved in pain transmission. However, the mechanism of action of MK-801 in pain-related neurons is not clear, and it is still unknown whether Glu is involved in the modulation of this processing. This study examines the effect of MK-801, Glu on the pain-evoked response of pain-excitation neurons (PENs) and pain-inhibition neurons (PINs) in the nucleus accumbens (NAc) of rats. The trains of electric impulses applied to the sciatic nerve were used as noxious stimulation. The electrical activities of PENs or PINs in NAc were recorded by a glass microelectrode. Our results revealed that the lateral ventricle injection of Glu increased the discharged frequency and shortened the discharged latency of PEN, and decreased the discharged frequency and prolonged the discharged inhibitory duration (ID) of PIN in NAc of rats evoked by the noxious stimulation, while intra-NAc administration of MK-801 produced the opposite response. On the basis of above findings we can deduce that Glu, MK-801 and N-methyl-D-aspartate (NMDA) receptor are involved in the modulation of nociceptive information transmission in NAc.
authors.affiliation: Department of Surgery, Neurology and Analysis of Second Affiliated Hospital, Harbin Medical University, Xuefu Road, No 194, Harbin 150081, China.
authors.forename: Tie-feng
authors.initials: TF
authors.lastname: Shi
authors.forename: Chun-xiao
authors.initials: CX
authors.lastname: Yang
authors.forename: Dong-xiao
authors.initials: DX
authors.lastname: Yang
authors.forename: Run-sheng
authors.initials: RS
authors.lastname: Jiao
authors.forename: Guang-wen
authors.initials: GW
authors.lastname: Zhang
authors.forename: He-ren
authors.initials: HR
authors.lastname: Gao
authors.forename: Duo
authors.initials: D
authors.lastname: Zhang
authors.forename: Man-ying
authors.initials: MY
authors.lastname: Xu
mesh_terms: D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D016291:Dizocilpine Maleate / Q000494:pharmacology*; D018698:Glutamic Acid / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D009714:Nucleus Accumbens / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects*
chemical_list: D000700:Analgesics; D016194:Receptors, N-Methyl-D-Aspartate; D018698:Glutamic Acid; D016291:Dizocilpine Maleate