In order to understand the dynamics of large neuronal networks, one of the challenges of nowadays neuroscience is to reach the possibility to record large ensembles of neurons simultaneously. In this context, microelectrode arrays (MEA) are gaining a rapidly growing interest. However, among several major problems, increased thermal noise becomes a limiting factor when the size of the microelectrodes becomes small and weak electrical activity has to be measured. In this work, we try to overcome this limitation by using porous microelectrode arrays. In order to combine the advantages of an overall small geometric surface with an increased active surface, standard MEAs are covered with a porous metal overlayer, obtained via the colloidal crystal templating method. Using this approach, we were able to obtain first promising results with respect to a reduction of the noise level. (C) 2011 Elsevier B.V. All rights reserved.