title: 5-Hydroxytryptamine 1A receptors inhibit glutamate release in rat medullary dorsal horn neurons.
abstract: We examined 5-hydroxytryptamine 1A (5-HT1A) receptor-mediated modulation of glutamatergic transmission in rat medullary dorsal horn neurons using a conventional whole-cell patch clamp technique. 5-HT reversibly and concentration dependently decreased the amplitude of glutamatergic excitatory postsynaptic currents and increased the paired-pulse ratio, indicating that 5-HT acts presynaptically to reduce glutamate release from primary afferents. The 5-HT-induced inhibition of excitatory postsynaptic currents was partially occluded by NAN-190, a 5-HT1A receptor antagonist, and mimicked by 8-OH-DPAT, a 5-HT1A receptor agonist. Our results suggest that presynaptic 5-HT1A receptors inhibit glutamate release from trigeminal primary afferents onto medullary dorsal horn neurons, and thus in addition to other 5-HT1 receptor subtypes, 5-HT1A receptors could be a potential target for treatment of pain from orofacial tissues.
authors: Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea.
authors: In-Sun
authors: IS
authors: Choi
authors: Jin-Hwa
authors: JH
authors: Cho
authors: Il-Sung
authors: IS
authors: Jang
mesh_terms: D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D018698:Glutamic Acid / Q000378:metabolism*; D018408:Patch-Clamp Techniques / Q000379:methods; D020671:Posterior Horn Cells / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism*; D017661:Receptors, Presynaptic / Q000187:drug effects; D012701:Serotonin / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects
chemical_list: D017661:Receptors, Presynaptic; D044282:Receptor, Serotonin, 5-HT1A; D012701:Serotonin; D018698:Glutamic Acid; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin