Effects of salicylate on serotoninergic activities in rat inferior colliculus and auditory cortex.
In vivo microdialysis offers a unique approach to monitor biochemical events related to brain function and metabolism, and has been used extensively in many systems to measure the release of endogenous transmitters and other neuroactive substances during normal and pathological conditions. The characterization of neurotransmitters' changes induced by salicylate in the inferior colliculus (IC) and the auditory cortex (AC) may provide insight into the action of salicylate on the auditory system and, through this, provide a better understanding of neurological mechanism of salicylate-induced tinnitus. In the present study, the effect of salicylate on 5-HT system in IC and AC has been monitored by microdialysis in salicylate-induced tinnitus animal models. Glucose and lactate levels in IC and AC were significantly increased after application of salicylate (350 mg/kg, i.p.), indicating a salicylate-related increase in regional neuronal activity. The 5-HT level increased to a maximum of 268+/-27% basal level in IC 2 h after application and of 277+/-24% basal level in AC around 3 h after application. These data suggest that the increases of 5-HT levels in IC and AC may be involved in the tinnitus generation.
Liu
Junxiu
J
Department of Otorhinolaryngology, Peking University Third Hospital, 49# Huayuan Road, Haidian District, Beijing 100083, PR China. liujunxiusanyuan@sina.com
Li
Xuepei
X
Wang
Lei
L
Dong
Yu
Y
Han
Huiwan
H
Liu
Guoquan
G
D000818:Animals; D001303:Auditory Cortex / Q000187:drug effects / Q000378:metabolism*; D015314:Dialysis Solutions / Q000737:chemistry; D005947:Glucose / Q000032:analysis; D007245:Inferior Colliculi / Q000187:drug effects / Q000378:metabolism*; D019344:Lactic Acid / Q000032:analysis; D017551:Microdialysis; D051381:Rats; D017208:Rats, Wistar; D012459:Salicylates / Q000378:metabolism / Q000494:pharmacology*; D012701:Serotonin / Q000032:analysis / Q000378:metabolism*; D014012:Tinnitus / Q000139:chemically induced* / Q000378:metabolism*
D015314:Dialysis Solutions; D012459:Salicylates; D012701:Serotonin; D019344:Lactic Acid; D005947:Glucose