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Functional role for interleukin‐1 in the injured peripheral taste system
Author(s) -
Shi Liqiao,
He Lianying,
Sarvepalli Padma,
McCluskey Lynnette Phillips
Publication year - 2012
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.22798
Subject(s) - taste , tongue , peripheral nerve injury , medicine , cytokine , nerve injury , receptor , proinflammatory cytokine , taste receptor , neuroscience , inflammation , pathology , biology , anesthesia , sciatic nerve
The peripheral taste system presents an excellent model for studying the consequences of neural injury, for the damaged nerve and sensory cells and the neighboring, intact neural cells. Sectioning a primary afferent nerve, the chorda tympani (CT), rapidly recruits neutrophils to both sides of the tongue. The bilateral neutrophil response induces transient functional deficits in the intact CT. Normal function is subsequently restored as macrophages respond to injury. We hypothesized that macrophages produce the proinflammatory cytokine interleukin (IL)‐1, which contributes to the maintenance of normal taste function after nearby injury. We demonstrate that IL‐1β protein levels are significantly increased on the injured side of the tongue at day 2 after injury. Dietary sodium deficiency, a manipulation that prevents macrophage recruitment, inhibits the elevation in IL‐1β. IL‐1β was expressed in several cell populations, including taste receptor cells and infiltrating neutrophils and macrophages. To test whether IL‐1 modulates taste function after injury, we blocked signaling with an IL‐1 receptor antagonist (IL‐1 RA) and recorded taste responses from the intact CT. This treatment inhibited the bilateral macrophage response to injury and impaired taste responses in the intact CT. Cytokine actions in the taste system are largely unstudied. These results demonstrate that IL‐1 has a beneficial effect on taste function after nearby injury, in contrast to its detrimental role in the injured central nervous system. © 2012 Wiley Periodicals, Inc.