  The phase response curve (PRC) is an important measure representing the
interaction between oscillatory elements. To understand synchrony in biological
systems, many research groups have sought to measure PRCs directly from
biological cells including neurons. Ermentrout et al. and Ota et al. showed
that PRCs can be identified through measurement of white-noise spike-triggered
averages. The disadvantage of this method is that one has to collect more than
ten-thousand spikes to ensure the accuracy of the estimate. In this paper, to
achieve a more accurate estimation of PRCs with a limited sample size, we use
colored noise, which has recently drawn attention because of its unique effect
on dynamical systems. We numerically show that there is an optimal colored
noise to estimate PRCs in the most rigorous fashion.
