Co-existence of tyrosine hydroxylase and calcitonin gene-related peptide in cochlear spiral modiolar artery of guinea pigs.
The distribution of tyrosine hydroxylase (TH) and calcitonin gene-related peptide (CGRP) on the cochlear spiral modiolar artery (SMA) was investigated in the guinea pig. The SMA was dissected from the modiolus so that the entire length of the vessel and many of its branches could be observed. Immunohistochemical labeling and double immunofluorescence were employed to localize each compound and to determine whether the TH and CGRP co-exist in neurons of the SMA. Microscopic examination of whole vessel preparations revealed numerous TH- and CGRP-positive neural networks innervating the SMA and its branches. The labeled neurons showed distinct arborization, varicosities and overlap, and were of different diameters. Confocal immunofluorescence microscopy of double-labeled TH and CGRP neurons showed that a number of the TH- and CGRP-positive neurons were co-labeled. Thus, TH and CGRP partially co-exist within the neuronal innervation of SMA. These findings support a hypothesis that specific neuropeptide and adrenergic neurons regulate cochlear blood flow.
Qiu
J
J
Xijing Hospital, Fourth Military Medical University, Xian, PR China.
Steyger
P S
PS
Trune
D R
DR
Nuttall
A L
AL
D000818:Animals; D001158:Arteries / Q000294:innervation / Q000378:metabolism; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism*; D003051:Cochlea / Q000098:blood supply*; D005455:Fluorescent Antibody Technique; D006168:Guinea Pigs; D007150:Immunohistochemistry; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism*
D014446:Tyrosine 3-Monooxygenase; D015740:Calcitonin Gene-Related Peptide