title: AMPA receptor stimulation mediates the antidepressant-like effect of a group II metabotropic glutamate receptor antagonist.
abstract: (1R,2R,3R,5R,6R)-2-amino-3-(3,4-dichlorobenzyloxy)-6-fluorobicyclo[3.1.0]hexane-2,6-dicarboxylic acid (MGS0039), a selective group II metabotropic glutamate receptor (mGluR) antagonist, exhibits antidepressant-like activities in rodent models. In the present studies, to clarify the involvement of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor activation in exhibition of the antidepressant-like properties of MGS0039, we examined the effect of an AMPA receptor antagonist, 2,3-dihydroxy-6-nitro-7-sulfamoylbenzo(f)quinoxaline (NBQX), on the antidepressant-like effect of MGS0039 in the mouse tail suspension test. We also examined the effects of NBQX on increased serotonin release after treatment with MGS0039 in the rat medial prefrontal cortex (mPFC) using in vivo microdialysis evaluation. In the tail suspension test, MGS0039 (0.3-3 mg/kg, i.p.) treatment dose-dependently and significantly reduced immobility time. Pretreatment with NBQX (10 mg/kg, s.c.) significantly prevented the antidepressant-like effect of MGS0039 in the tail suspension test, while NBQX itself had no effect on immobility time. In the microdialysis evaluation, administration of MGS0039 (10 mg/kg, i.p.) significantly increased serotonin levels in mPFC in freely moving rats, while NBQX (1 mg/kg, i.p.) itself had no effect on serotonin release in this region. Pretreatment with NBQX significantly attenuated the increase in serotonin release by MGS0039. These findings suggest that stimulation of postsynaptic AMPA receptors plays a role in mediating the pharmacological effects of MGS0039.
authors.affiliation: Medicinal Pharmacology Laboratory, Taisho Pharmaceutical Co., Ltd., Kita-ku, Saitama 331-9530, Japan.
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Karasawa
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Shimazaki
authors.forename: Naoya
authors.initials: N
authors.lastname: Kawashima
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Chaki
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D018687:Antidepressive Agents, Second-Generation / Q000494:pharmacology; D001643:Bridged Bicyclo Compounds / Q000494:pharmacology*; D003998:Dicarboxylic Acids / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004336:Drug Antagonism; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D016666:Fluvoxamine / Q000494:pharmacology; D046353:Immobility Response, Tonic / Q000187:drug effects; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D017551:Microdialysis; D017397:Prefrontal Cortex / Q000737:chemistry / Q000187:drug effects; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors*; D018094:Receptors, Metabotropic Glutamate / Q000037:antagonists & inhibitors*; D012701:Serotonin / Q000032:analysis
chemical_list: C483757:2-amino-3-(3,4-dichlorobenzyloxy)-6-fluorobicyclo(3.1.0)hexane-2,6-dicarboxylic acid; D000928:Antidepressive Agents; D018687:Antidepressive Agents, Second-Generation; D001643:Bridged Bicyclo Compounds; D003998:Dicarboxylic Acids; D018691:Excitatory Amino Acid Antagonists; D011810:Quinoxalines; D018091:Receptors, AMPA; D018094:Receptors, Metabotropic Glutamate; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; D012701:Serotonin; D016666:Fluvoxamine