ISSN:
1432-0878
Keywords:
Ear, middle
;
Retrograde tracing
;
Substance P
;
Neurokinin A
;
Calcitonin gene-related peptide
;
Rat, Sprague-Dawley
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary The distribution and origin of nerve fibers of presumed sensory nature in the ear drum and middle-ear mucosa of the rat were studied by a retrograde tracing technique in combination with immunocytochemistry. Application of True Blue (TB) on the ear drum or on the middle-ear mucosa labeled nerve cell bodies in the jugular, trigeminal, geniculate and cervical dorsal root ganglia (C2–C4). Judging from the number of TB-labeled nerve cell bodies the jugular and trigeminal ganglia contributed the major component to the sensory innervation of the ear drum and the middle-ear mucosa, while the contribution from the geniculate and cervical dorsal root ganglia was relatively minor. The majority of the TB-labeled nerve cell bodies contained calcitonin gene-related peptide (CGRP), whereas minor populations stored substance P (SP) and neurokinin A (NKA). Nerve fibers containing SP, NKA and CGRP were moderate in number in the middle-ear mucosa and few in the ear drum. Double immunostaining revealed that SP invariably coexisted with NKA in nerve cell bodies in the ganglia examined. The SP/NKA-containing nerve cell bodies constituted a subpopulation of those storing CGRP. The findings indicate that several ganglia project to the ear drum and middle-ear mucosa and that many neuropeptides are involved in the mediation of middle-ear sensitivity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00213835
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