抄録
Noise analysis of the membrane current has been used for long period of time as one of the most powerful tools for the study of membrane excitability. Even after the development of the patch clamp, noise analyses have been employed when the channel density is not appropriate for the patch recordings. Also, one of the biggest benefits is that the technique can be applicable, as a triggering survey, for the whole-cell currents whose unitary properties are totally unknown. Generally, however, the technique has been less used, mostly because of the difficulties of the logics and analyses. In the present work, we developed a computer program executing all processes for the noise analysis running on the MS-Windows .NET Framework. This Windows application can specify the time window for data analyses, calculation of the mean and variance, and least square fitting of the data to provide unitary current amplitude and the total number of the channels. As an example for application, we addressed to a quantitative analysis of voltage-gated Na+ channels of the olfactory receptor cell in which Na+ channels play a crucial role for the spike generation. We confirmed that the non-stationary noise analysis was a valuable tool for estimating the quantum features of Na+ channels. Together, properties of the voltage-gated Na+ currents will be discussed in relation to the neuronal signal encoding. [J Physiol Sci. 2008;58 Suppl:S71]
