title: Metabotropic Glutamate Receptor 7 (mGluR7) as a Target for Modulating Pain-evoked Activities of Neurons in the Hippocampal CA3 Region of Rats.
abstract: BACKGROUND
  Metabotropic glutamate could contribute to the development of neuropathic pain-related behaviors. Previously, we have confirmed that the glutamic acid and dizocilpine maleate in the hippocampal CA3 region are involved in the modulation of noxious stimulation. However, whether the metabotropic glutamate receptor 7 (mGluR7) can modulate the pain-evoked electrical activities of pain-excited neurons and pain-inhibited neurons in the hippocampal CA3 region is not clear.
  
  
  OBJECTIVE
  The study aimed to examine the effects of mGluR7 allosteric agonist N,N'-dibenzhydrylethane- 1,2-diamine dihydrochloride (AMN082) and antagonist 6-(4-methoxyphenyl)-5-methyl-3- pyridin-4-ylisoxazolo[4,5-c]pyridin-4(5H)-one (MMPIP) on the pain-evoked electrical activities of pain-excited neurons and pain-inhibited neurons in the CA3 region of rats.
  
  
  METHODS
  A train of electric impulses applied to the sciatic nerve were used for noxious stimulation. The bio-electrical activities of pain-excited neuron or pain-inhibited neuron in the CA3 region were recorded by a glass microelectrode.
  
  
  RESULTS
  Our results exhibited that intra-CA3 region administration of the glutamic acid or AMN082 increased the pain-evoked discharged frequency and shortened the latency of pain-excited neuron, while decreased the pain-evoked discharged frequency and prolonged the inhibitory duration of paininhibited neuron in the CA3 region. The intra-CA3 region microinjection of MMPIP produced the opposite response.
  
  
  CONCLUSIONS
  These findings demonstrated that the glutamic acid and mGluR7 in hippocampal CA3 region are involved in the modulation of nociceptive information transmission by regulating pain-evoked electric activities of pain-excited neurons and pain-inhibited neurons.
authors.affiliation: Department of Neurology, Analysis and Surgery of Second Affiliated Hospital, Harbin Medical University, Harbin 150081, China.
authors.forename: Xinya
authors.initials: X
authors.lastname: Wei
authors.affiliation: Department of Neurology, Analysis and Surgery of Second Affiliated Hospital, Harbin Medical University, Harbin 150081, China.
authors.forename: Dongxiao
authors.initials: D
authors.lastname: Yang
authors.affiliation: Department of Neurology, Analysis and Surgery of Second Affiliated Hospital, Harbin Medical University, Harbin 150081, China.
authors.forename: Tiefeng
authors.initials: T
authors.lastname: Shi
authors.affiliation: Department of Neurology, Analysis and Surgery of Second Affiliated Hospital, Harbin Medical University, Harbin 150081, China.
authors.forename: Jianing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Neurology, Analysis and Surgery of Second Affiliated Hospital, Harbin Medical University, Harbin 150081, China.
authors.forename: Yunling
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Department of Neurology, Analysis and Surgery of Second Affiliated Hospital, Harbin Medical University, Harbin 150081, China.
authors.forename: Xuezhu
authors.initials: X
authors.lastname: Qiao
authors.affiliation: Department of Neurology, Second Affiliated Hospital, Harbin Medical University, Harbin 150081, China.
authors.forename: Chunxiao
authors.initials: C
authors.lastname: Yang
authors.affiliation: Laboratory of Neural Electrophysiology, Department of Physiology, Harbin Medical University, Harbin 150081, China.
authors.forename: Manying
authors.initials: M
authors.lastname: Xu
mesh_terms: D018712:Analgesics, Non-Narcotic / Q000494:pharmacology; D000818:Animals; D001559:Benzhydryl Compounds / Q000494:pharmacology; D056654:CA3 Region, Hippocampal / Q000187:drug effects / Q000378:metabolism*; D018683:Excitatory Amino Acid Agents / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism; D008297:Male; D008839:Microelectrodes; D009437:Neuralgia / Q000188:drug therapy / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D059226:Nociceptive Pain / Q000188:drug therapy / Q000378:metabolism*; D011728:Pyridones / Q000494:pharmacology; D017208:Rats, Wistar; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists / Q000378:metabolism*; D012584:Sciatic Nerve / Q000503:physiopathology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
chemical_list: C553164:6-(4-methoxyphenyl)-5-methyl-3-pyridin-4-ylisoxazonolo(4,5-c)pyridin-4(5H)-one; D018712:Analgesics, Non-Narcotic; D001559:Benzhydryl Compounds; D018683:Excitatory Amino Acid Agents; C507346:N,N'-dibenzhydrylethane-1,2-diamine dihydrochloride; D011728:Pyridones; D018094:Receptors, Metabotropic Glutamate; C102719:metabotropic glutamate receptor 7; D018698:Glutamic Acid
keywords: 2-diamine dihydrochloride; 5-c]pyridin-4(5H)-one; 6-(4-methoxyphenyl)-
  5-methyl-3-pyridin-4-ylisoxazolo[4; Algesia modulation; Electrophysiology; Hippocampal CA3 region; Metabotropic glutamate receptor 7; N; N'-dibenzhydryl-ethane-1