[Thermal influence on intracellular calcium concentration of isolated vestibular hair cells in guinea pig].

OBJECTIVE

To further understand the mechanism of caloric test.

METHODS

Vestibular hair cells(VHC) were isolated from guinea pig crista ampullaris by enzymatic and mechanical methods and the variations of intracellular free calcium ion concentration ([Ca2+]i) with changes of the extracellular medium temperature were observed. The [Ca2+]i of VHC was examined using laser scanning confocal microscopy (LSCM) and the Ca2+ sensitive dye Fluo-3.

RESULTS

Were as follows: 1. There was an increase in [Ca2+]i of 81.8% (18/22) type I VHC and 7/12 type II VHC with the heat stimulation and a decrease in [Ca2+]i with temperature decrease. The magnitude of variation in [Ca2+] i in type I VHC was larger than that in type II VHC. 2. There was no significant change in [Ca2+]i of outer hair cells (OHC) with the heat stimulation.

CONCLUSION

There is a direct thermal influence on vestibular sensory cells and this influence accompany with the variation of [Ca2+]i in VHC.