Ryanodine receptor localisation in the mammalian cochlea: an ultrastructural study
| Autor: | Carole Hackney, Lisa Grant, Helen J. Kennedy, S. M. Slapnick |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
medicine.medical_specialty
Efferent Biology Rats Sprague-Dawley Neurons Efferent Antibody Specificity Internal medicine Hair Cells Auditory otorhinolaryngologic diseases medicine Animals Inner ear Cochlea integumentary system Ryanodine receptor Endoplasmic reticulum Ryanodine Receptor Calcium Release Channel Immunohistochemistry Sensory Systems Cell biology Rats medicine.anatomical_structure Endocrinology Organ of Corti Calcium sense organs Hair cell Calcium-induced calcium release |
| Zdroj: | Hearing research. 219(1-2) |
| ISSN: | 0378-5955 |
| Popis: | Calcium-induced calcium release (CICR) in the mammalian cochlea has been suggested to enhance neurotransmitter release from inner hair cells and facilitate the efferent response in outer hair cells. Light microscopic evidence exists for the presence of ryanodine receptors in the organ of Corti but there is so far no information about their ultrastructural localisation. We have therefore used post-embedding immunogold labeling with antibodies that predominantly recognise ryanodine receptor isoforms 1 (RyR1) and 2 (RyR2) to investigate their distribution in rat cochleae. In inner hair cells, the highest levels of labeling were observed over an area of rough endoplasmic reticulum that lies in the cytoplasmic region beneath the nucleus; in outer hair cells, the cytoplasmic region above the nucleus displayed most labeling. Labeling was also associated with the subsurface cisternae adjacent to the lateral membranes of both types of hair cell, with the efferent terminals on the outer hair cells and was observed in adjacent supporting cells. Labeling in outer hair cells was significantly higher than that in inner hair cells or in the supporting cells. Our results support the presence of RyR1 in the cochlea but do not rule out the presence of other isoforms. CICR may be involved in the control of calcium levels in the base of the inner hair cells and supporting cells, and in the cholinergic efferent response and motile behaviour of the outer hair cells. |
| Databáze: | OpenAIRE |
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