One of the best approaches to understanding the mechanism of information acquisition and storage is to characterize the plasticity of network activity by monitoring and stimulating individual neurons in a topologically defined network and doing this for extended periods of time. We therefore previously developed an on-chip multi-electrode array (MEA) system combined with an array of agarose microchambers (AM,Cs). It is possible to record the firing at multiple cells simultaneously for long term and topographically control the cells position and their connections. In our present study, we demonstrated the effect of tetanic stimulation in a linearly lined-up patterned network on the AMC/MEA chip. We detected reproducible activity changes that were induced by tetanic stimulation and saw that these changes were maintained for 6-24 h. The results show the advantage of our ANIC/MEA cultivation and measurements methods and suggest they will be useful for investigating the long-term plasticity depending on network topology and size. @ 2007 Elsevier Inc. All rights reserved.