Recent paper of interest. Naundorf B, Wolf F, Volgushev M. (2006) Unique features of action potential initiation in cortical neurons. Nature. 440(7087):1060-1063. . Schneidman E, Berry II, MJ, Segev R, Bialek W (2006) Weak pairwise correlations imply strongly correlated network states in a neural population. Nature. 440(7087):1007-1012. .