title: Sodium salicylate suppresses serotonin-induced enhancement of GABAergic spontaneous inhibitory postsynaptic currents in rat inferior colliculus in vitro.
abstract: Available evidence suggests that sodium salicylate (SS) may produce tinnitus through altering the balance between inhibition and excitation in the central auditory system. Since serotonin (5-hydroxytryptamine, 5-HT) containing fibers preferentially innervate inhibitory GABA neurons, there exists a possibility that SS causes the imbalance between inhibition and excitation through influencing serotonergic modulation of the GABAergic synaptic transmission. In the present study, we examined the effects of SS on 5-HT-mediated GABAergic spontaneous inhibitory postsynaptic currents (sIPSCs) from neurons of the central nucleus of rat inferior colliculus with whole-cell patch-clamp technique and brain slice preparation. Perfusion of 40 microM 5-HT robustly enhanced both frequency and amplitude of GABAergic sIPSCs and this 5-HT-induced enhancement of GABAergic sIPSCs could be suppressed by 1.4mM SS. Tetrodotoxin at 0.5 microM produced a similar effect as SS did, suggesting that SS suppresses the 5-HT-induced enhancement of GABAergic sIPSCs through depressing spontaneous action potentials of GABA neurons. Our findings suggest that SS may preferentially target GABA neurons and consequently interrupt a normal level of GABAergic synaptic transmissions maintained by the serotonergic system in SS-induced tinnitus.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei 230027, China.
authors.forename: Hai-Tao
authors.initials: HT
authors.lastname: Wang
authors.forename: Bin
authors.initials: B
authors.lastname: Luo
authors.forename: Yi-Na
authors.initials: YN
authors.lastname: Huang
authors.forename: Ke-Qing
authors.initials: KQ
authors.lastname: Zhou
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000633:toxicity; D001307:Auditory Perception / Q000187:drug effects / Q000502:physiology; D005260:Female; D066298:In Vitro Techniques; D007245:Inferior Colliculi / Q000187:drug effects* / Q000502:physiology*; D053444:Inhibitory Postsynaptic Potentials / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008959:Models, Neurological; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology*; D012980:Sodium Salicylate / Q000633:toxicity*; D013779:Tetrodotoxin / Q000633:toxicity; D014012:Tinnitus / Q000139:chemically induced / Q000503:physiopathology; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; C042390:alpha-methylserotonin; D012701:Serotonin; D013779:Tetrodotoxin; D005680:gamma-Aminobutyric Acid; D012980:Sodium Salicylate