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Brain‐derived neurotrophic factor‐, neurotrophin‐3‐, and tyrosine kinase receptor‐like immunoreactivity in lingual taste bud fields of mature hamster
Author(s) -
Ganchrow Donald,
Ganchrow Judith R.,
VerdinAlcazar Mary,
Whitehead Mark C.
Publication year - 2002
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.2162
Subject(s) - tropomyosin receptor kinase b , tropomyosin receptor kinase c , taste bud , neurotrophin , lingual papilla , biology , low affinity nerve growth factor receptor , brain derived neurotrophic factor , tropomyosin receptor kinase a , neurotrophin 3 , neurotrophic factors , microbiology and biotechnology , trk receptor , medicine , endocrinology , taste receptor , neuroscience , receptor , taste , biochemistry , platelet derived growth factor receptor , growth factor
The neurotrophins brain‐derived neurotrophic factor (BDNF) and neurotrophin‐3 (NT‐3), as well as their respective tyrosine kinase (Trk) receptors, TrkB and TrkC, influence peripheral target cell innervation, survival, and proliferation. In the mature taste system the role of neurotrophins and their receptors is not known. The mature hamster is an intriguing model because anterior lingual fungiform, unlike posterior lingual foliate and circumvallate, taste buds survive denervation. In light of this difference, we examined whether the degree of neurotrophin‐ or neurotrophin receptor‐like immunoreactivity (IR) normally differs among lingual gemmal fields. In single‐ and double‐labeled immunofluorescent experiments, 3,209 taste bud sections (profiles) from 13 hamsters were examined for immunopositive gemmal cells or nerve fibers using antibodies to BDNF and NT‐3, their respective receptors TrkB and TrkC, and the neural marker ubiquitin c‐terminal hydrolase L‐1 [protein gene product (PGP) 9.5]. In each gemmal field, more than 75% of taste bud profiles showed immunopositivity to BDNF, NT‐3, and TrkB. Across bud fields, BDNF‐, TrkB‐, and BDNF/TrkB‐like IR, as well as PGP 9.5 and PGP 9.5/BDNF‐like IR in centrally located, fungiform bud cells was greater ( P < 0.0001 to P < 0.002) than in circumvallate or foliate buds. Within bud fields, the number of BDNF‐like, labeled bud cells/bud profile was greater than that for NT‐3‐like IR in fungiform ( P < 0.0002) and foliate ( P < 0.0001) buds. TrkC was immunonegative in gemmal cells. The average density of TrkB‐ and TrkC‐like fiber IR was more pronounced in fungiform than posterior gemmal‐bearing papillae. Thus, fungiform papillae, whose taste buds are least affected by denervation, exhibit specific neurotrophin and receptor enrichment. J. Comp. Neurol. 455:11–24, 2003. © 2002 Wiley‐Liss, Inc.