Editorial

Several years ago the analysis of the human genome was resulting in the disappointing finding that humans have only about 30 000 genes compared to expected 100 000 ones. Now only 25 000 genes are estimated. This finding made clear that the control of organismic structures and functions can only be understood by the multi-component analysis of genomic actions. Additionally, new analytical high-throughput technologies such as DNA microarrays provided a huge amount of data on gene expression that can not be understood by classical mathematical tools. Instead of this, besides multivariate statistics also graph theoretical approaches and genetic programming are promising tools for analysis of complex data sets. The necessity of using mathematical tools in molecular biology in the late 1990s and early 2000s were summarized with the terms “computational molecular biology”. Additionally, in order to understand the functions of the various biomolecules in the cellular and supracellular context the approach of systems thinking was proposed by Kitano with the term “Systems biology”. This approach aims to construct a cell on the level of a computerized mathematical model. This “in-silico-modelling” allows studying the behaviour of complex dynamic systems under various conditions. With these results new experiments in the “wet” laboratory can be performed. New data should allow modifications of the model and so the cycle of scientific knowledge is proceeding.

Systems biology mainly was applied in modelling of simple organisms, on apoptosis, some metabolic pathways and cancer. It is an exploding field. Increasing amount of information on the molecular mechanisms in neurons now opens the question if systems biology can be useful in order to understand molecular networks that are involved in neuronal signalling and processing. Up to now, only a few initiatives into that direction can be seen. Consequently, in 2007 we organized a workshop on “Systems Biology and Psychiatry” that was addressing the dopaminergic intracellular signalling network as an important molecular microcircuitry relevant to symptomatic and therapeutic aspects of schizophrenia. This volume is representing essential contributions to this workshop.

This workshop was the third of a series of workshops an “Computational Neuropsychiatry” beginning in 2005 at the mental hospital Haar (Munich/FRG). We started with the work of Arvid Carlsson about the possible role of several specific neuronal loops for pathophysiology and therapy of schizophrenia. At this workshop we had the chance to discuss the theoretical concepts that he proposed already many years before. Physicists, mathematicians and computational scientists were integrated in this workshop with psychiatrists and pharmacologists, whose lectures were published in 2006 as a Supplement volume of Pharmacopsychiatry. Because of the considerable success of this first meeting we proceeded in our attempts to integrate computational neuroscience with biological psychiatry. Our second workshop was focussing on the role of dopamine in working memory deficits in schizophrenia, presumably related to dysfunctions of prefrontal cortical networks. The presentations of this meeting, together with some additional papers related to the topic are summarized in the present supplement of Pharmacopsychiatry as Vol.2 devoted to “Computational Neuropsychiatry”.

The next workshop that was focussed on “systems biology and addiction” and was organized in April 2008. The results of this workshop will be published soon.

We gratefully acknowledge that the 2007 workshop and this publication have only been possible by a generous educational grant by Pfizer GmbH.

F. Tretter, J. Gallinat, W. E. Müller Munich, Berlin and Frankfurt

June 2008

Correspondence