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Coupling between cochlear fibrocytes and microvessels of spiral ligament in guinea pig cochlea
Author(s) -
Nuttall Alfred L.,
Shi Xiaorui
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.767.14
Subject(s) - spiral ligament , fibrocyte , cochlea , biophysics , chemistry , calcium , anatomy , microbiology and biotechnology , biology , organ of corti , organic chemistry
The dynamic regulation of oxygen and the supply of glucose to match changes in metabolic demand are critical to the maintenance of cochlear homeostasis. Although spiral modiolar artery autoregulation is one control mechanism for the reaction to systemic blood pressure and energy changes of the whole cochlea, another local mechanism may be active at the level of capillaries. With transmission electron microscopy combined with fluorescence confocal imaging, we found that fibrocytes are uniquely positioned and spatially distributed near pre‐capillaries and post‐capillaries of the spiral ligament. Inter‐connected fibrocytes were positive to Na+/K+ ATPase β1 and connexin 40. With fluo‐4, a fluorescent calcium indicator, we found that connected fibrocytes contained relatively high calcium signals in comparison with other cells in cochlear lateral wall. Photolysis of the caged divalent ion chelator NP‐EGTA in fibrocytes resulted in calcium signal propagation to neighbor cells, including the vascular cells: pericytes and endothelial cells. The connection between the fibrocytes and the vascular cells suggests a "fibro‐vascular" coupling in the cochlear microvessel system in the spiral ligament. This signal pathway may be important for the local blood flow control to meet cellular metabolic needs. Supported: NIDCD DC 008888, NIDCDDC 00105, DC 005983