Aim: 

The calcium activated chloride current constitutes a large part of the transduction current in olfactory sensory neurons. This current has not been fully characterized and its molecular identity is still not well established. In the present study we aim to characterize the biophysical properties of such chloride conductance in isolated olfactory sensory neurons from mouse.

Methods: 

We used the whole-cell patch clamp technique in the voltage-clamp configuration to record currents elicited by calcium photorelease in the ciliary region of mouse olfactory sensory neurons.

Results: 

Preliminary results showed that the reversal potential of the current in symmetrical chloride concentration was about 0 mV. The permeability sequence, obtained in external chloride substitution experiments, was I > SCN > NO₃ > Br > Cl > MeS. Chloride current blockers, such as Niflumic acid, DIDS and NPPB, reduced the current amplitude.

Conclusion: 

The biophysical characterization of the olfactory Ca-activated chloride current, might be compared to data obtained from ion channels candidate to be the olfactory channel involved in transduction. The molecular identification of the calcium-activated chloride conductance will be a further step in the complete understanding of the olfactory transduction.