[The role of intracellular Ca2+ release in olfactory signal transduction].

OBJECTIVE

To setup the real time monitor system of the concentration of free intracellular calcium ([Ca2+]i) of olfactory receptor neurons (ORNs) cultured from olfactory epithelium explant, and to analyze the role of several important components in olfactory signal transduction.

METHOD

The [Ca2+]i of the cultured ORNs was determined by fluorescence microscopy using the fluorescent calcium indicator, Fura-2 AM, and calculated by means of dual-wavelength ratiometric method. Forskolin and IBMX were used to stimulate the cultured ORNs respectively. The source of corresponding [Ca2+]i elevation was studied by the depletion of extracellular or intracellular calcium.

RESULT

The [Ca2+]i of silent ORNs was (58.5 +/- 12.8) nmol/L. Forskolin or IBMX stimulation led to reversible accumulation of [Ca2+]i in the ORNs. The [Ca2+]i change was abolished with the removal of extracellular Ca2+ and un-affected by treatment with thapsigargin.

CONCLUSION

A system to visualize and quantify [Ca2+]i of the ORNs was established. [Ca2+]i of the ORNs was regulated by second messenger gated calcium channels.