HPLC detection of serotonin within the rat cochlea.
This study was performed to analyse the cochlear concentrations of serotonin (5-HT) and 5-hydroxyindole-3-acetic acid (5-HIAA), their sources and modifications induced by noise exposure. Superior cervical ganglionectomy did not modify these concentrations. However, removal of the blood by aortic perfusion reduced significantly (about 76%) the cochlear concentration of 5-HT without affecting the 5-HIAA concentration. These results indicate that blood constitutes an important source of 5-HT to the cochlea, opposite to the superior cervical ganglion. Exposure to noise at 90 dB SPL did not modify the total cochlear concentrations of 5-HT and 5-HIAA, or the concentrations remaining after removal of the blood, suggesting that 5-HT could have a modulatory role in the cochlea distinct from that of olivocochlear neurotransmitters.
Vicente-Torres
A
A
Centro de Cultivos Celulares (CAI-UCM) and Departamento de Cirugía II (ORL), Facultad de Medicina, Universidad Complutense, Madrid, Spain.
Bartolomé
M V
MV
Carricondo
F
F
Esquifino
A
A
Gil-Loyzaga
P
P
D000161:Acoustic Stimulation; D000704:Analysis of Variance; D000818:Animals; D001011:Aorta; D002851:Chromatography, High Pressure Liquid; D003051:Cochlea / Q000737:chemistry* / Q000378:metabolism; D006897:Hydroxyindoleacetic Acid / Q000032:analysis / Q000378:metabolism; D008297:Male; D009622:Noise; D010477:Perfusion; D051381:Rats; D020318:Rats, Long-Evans; D012701:Serotonin / Q000032:analysis* / Q000378:metabolism; D017783:Superior Cervical Ganglion / Q000737:chemistry; D009435:Synaptic Transmission / Q000502:physiology
D012701:Serotonin; D006897:Hydroxyindoleacetic Acid