Capillary electrophoresis of insulin-like growth factors: enhanced ultraviolet detection using dynamically coated capillaries and on-line solid-phase extraction |
| |
Authors: | ME Roche MA Anderson RP Oda BL Riggs MA Strausbauch R Okazaki PJ Wettstein JP Landers |
| |
Affiliation: | LPS, Ecole Normale Supérieure, 24 rue Lhomond, Paris Cedex 05, 75231, France. |
| |
Abstract: | We consider a model of an integrate-and-fire neuron with synaptic current dynamics, in which the synaptic time constant tau' is much smaller than the membrane time constant tau. We calculate analytically the firing frequency of such a neuron for inputs described by a random Gaussian process. We find that the first order correction to the frequency due to tau' is proportional to the square root of the ratio between these time constants radicaltau'/tau. This implies that the correction is important even when the synaptic time constant is small compared with that of the potential. The frequency of a neuron with tau'>0 can be reduced to that of the basic IF neuron (corresponding to tau'=1) using an "effective" threshold which has a linear dependence on radical tau'/tau. Numerical simulations show a very good agreement with the analytical result, and permit an extrapolation of the "effective" threshold to higher orders in radical tau'/tau. The obtained frequency agrees with simulation data for a wide range of parameters. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|