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Taste Bud-Derived BDNF Is Required to Maintain Normal Amounts of Innervation to Adult Taste Buds.

Meng L, Ohman-Gault L, Ma L, Krimm RF - eNeuro (2015)

Bottom Line: We then tested the idea that that the taste bud was the source of this BDNF by reducing Bdnf levels specifically in the lingual epithelium and taste buds.Taste buds were confirmed as the source of BDNF regulating innervation.We conclude that BDNF expressed in taste receptor cells is required to maintain normal levels of innervation in adulthood.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine , Louisville, Kentucky 40292.

ABSTRACT
Gustatory neurons transmit chemical information from taste receptor cells, which reside in taste buds in the oral cavity, to the brain. As adult taste receptor cells are renewed at a constant rate, nerve fibers must reconnect with new taste receptor cells as they arise. Therefore, the maintenance of gustatory innervation to the taste bud is an active process. Understanding how this process is regulated is a fundamental concern of gustatory system biology. We speculated that because brain-derived neurotrophic factor (BDNF) is required for taste bud innervation during development, it might function to maintain innervation during adulthood. If so, taste buds should lose innervation when Bdnf is deleted in adult mice. To test this idea, we first removed Bdnf from all cells in adulthood using transgenic mice with inducible CreERT2 under the control of the Ubiquitin promoter. When Bdnf was removed, approximately one-half of the innervation to taste buds was lost, and taste buds became smaller because of the loss of taste bud cells. Individual taste buds varied in the amount of innervation each lost, and those that lost the most innervation also lost the most taste bud cells. We then tested the idea that that the taste bud was the source of this BDNF by reducing Bdnf levels specifically in the lingual epithelium and taste buds. Taste buds were confirmed as the source of BDNF regulating innervation. We conclude that BDNF expressed in taste receptor cells is required to maintain normal levels of innervation in adulthood.

No MeSH data available.


Related in: MedlinePlus

Taste buds have reduced P2X3-positive innervation after Bdnf reduction. A–F, Representative whole taste buds labeled with cytokeratin-8 (green) and P2X3 (red) are shown for control (Bdnflox/-, Bdnflox/+) and experimental (K14-CreER Bdnflox/-) genotypes 10 weeks after tamoxifen administration. Taste buds in (C, F) K14-CreER Bdnflox/mice appeared to have reduced innervation compared with (A, D) Bdnflox/+ and (B, E) Bdnflox/- mice. F, Some taste buds in K14-CreER Bdnflox/- mice were smaller than normal, (C) whereas others were normal in size. G, The volume of P2X3 innervation in taste buds was reduced in K14-CreER Bdnflox/- mice compared with Bdnflox/- and Bdnflox/+ mice, but (H) taste bud volume was not affected by Bdnf reduction. Scale bar, 20 µm. *p ≤ 0.05.
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Figure 8: Taste buds have reduced P2X3-positive innervation after Bdnf reduction. A–F, Representative whole taste buds labeled with cytokeratin-8 (green) and P2X3 (red) are shown for control (Bdnflox/-, Bdnflox/+) and experimental (K14-CreER Bdnflox/-) genotypes 10 weeks after tamoxifen administration. Taste buds in (C, F) K14-CreER Bdnflox/mice appeared to have reduced innervation compared with (A, D) Bdnflox/+ and (B, E) Bdnflox/- mice. F, Some taste buds in K14-CreER Bdnflox/- mice were smaller than normal, (C) whereas others were normal in size. G, The volume of P2X3 innervation in taste buds was reduced in K14-CreER Bdnflox/- mice compared with Bdnflox/- and Bdnflox/+ mice, but (H) taste bud volume was not affected by Bdnf reduction. Scale bar, 20 µm. *p ≤ 0.05.

Mentions: Statistical table


Taste Bud-Derived BDNF Is Required to Maintain Normal Amounts of Innervation to Adult Taste Buds.

Meng L, Ohman-Gault L, Ma L, Krimm RF - eNeuro (2015)

Taste buds have reduced P2X3-positive innervation after Bdnf reduction. A–F, Representative whole taste buds labeled with cytokeratin-8 (green) and P2X3 (red) are shown for control (Bdnflox/-, Bdnflox/+) and experimental (K14-CreER Bdnflox/-) genotypes 10 weeks after tamoxifen administration. Taste buds in (C, F) K14-CreER Bdnflox/mice appeared to have reduced innervation compared with (A, D) Bdnflox/+ and (B, E) Bdnflox/- mice. F, Some taste buds in K14-CreER Bdnflox/- mice were smaller than normal, (C) whereas others were normal in size. G, The volume of P2X3 innervation in taste buds was reduced in K14-CreER Bdnflox/- mice compared with Bdnflox/- and Bdnflox/+ mice, but (H) taste bud volume was not affected by Bdnf reduction. Scale bar, 20 µm. *p ≤ 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4697083&req=5

Figure 8: Taste buds have reduced P2X3-positive innervation after Bdnf reduction. A–F, Representative whole taste buds labeled with cytokeratin-8 (green) and P2X3 (red) are shown for control (Bdnflox/-, Bdnflox/+) and experimental (K14-CreER Bdnflox/-) genotypes 10 weeks after tamoxifen administration. Taste buds in (C, F) K14-CreER Bdnflox/mice appeared to have reduced innervation compared with (A, D) Bdnflox/+ and (B, E) Bdnflox/- mice. F, Some taste buds in K14-CreER Bdnflox/- mice were smaller than normal, (C) whereas others were normal in size. G, The volume of P2X3 innervation in taste buds was reduced in K14-CreER Bdnflox/- mice compared with Bdnflox/- and Bdnflox/+ mice, but (H) taste bud volume was not affected by Bdnf reduction. Scale bar, 20 µm. *p ≤ 0.05.
Mentions: Statistical table

Bottom Line: We then tested the idea that that the taste bud was the source of this BDNF by reducing Bdnf levels specifically in the lingual epithelium and taste buds.Taste buds were confirmed as the source of BDNF regulating innervation.We conclude that BDNF expressed in taste receptor cells is required to maintain normal levels of innervation in adulthood.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine , Louisville, Kentucky 40292.

ABSTRACT
Gustatory neurons transmit chemical information from taste receptor cells, which reside in taste buds in the oral cavity, to the brain. As adult taste receptor cells are renewed at a constant rate, nerve fibers must reconnect with new taste receptor cells as they arise. Therefore, the maintenance of gustatory innervation to the taste bud is an active process. Understanding how this process is regulated is a fundamental concern of gustatory system biology. We speculated that because brain-derived neurotrophic factor (BDNF) is required for taste bud innervation during development, it might function to maintain innervation during adulthood. If so, taste buds should lose innervation when Bdnf is deleted in adult mice. To test this idea, we first removed Bdnf from all cells in adulthood using transgenic mice with inducible CreERT2 under the control of the Ubiquitin promoter. When Bdnf was removed, approximately one-half of the innervation to taste buds was lost, and taste buds became smaller because of the loss of taste bud cells. Individual taste buds varied in the amount of innervation each lost, and those that lost the most innervation also lost the most taste bud cells. We then tested the idea that that the taste bud was the source of this BDNF by reducing Bdnf levels specifically in the lingual epithelium and taste buds. Taste buds were confirmed as the source of BDNF regulating innervation. We conclude that BDNF expressed in taste receptor cells is required to maintain normal levels of innervation in adulthood.

No MeSH data available.


Related in: MedlinePlus