The above schema is a visualization of the levels of organization studied by the community of researchers within the CIN. The final goal is to use this knowledge for human applications, typically in medicine as well as for the advancement of modern technologies such as information technology, robotics and artificial intelligence. The graphic also highlights the important role of theoretical neurobiology in guiding experimental work at all levels of organization. Finally, the endeavour as a whole must be accompanied by a philosophical analysis of concepts and paradigms, as well as by ethical considerations.
All of biology starts at the level of genetics. In the past there have been high hopes that seemingly complex phenomenons might turn out simpler than expected if they could be traced back to individual genes. However, it turned out that the idea that all complex brain function or neurological disease can be directly and causally related to individual genes is not realistic. The reason is that the diseases where it is theoretically possible to ‘repair’ a single gene and thereby heal the patient are a tiny minority among all known brain diseases. No complex brain function has been found that is caused by one single gene. The reason is that most neuronal functions and dysfunctions are not ‘caused’ by genes in the strict sense. Rather, complex networks of genes ‘predispose’ the brain to function or dysfunction in certain ways. Theoretically, predicting exactly the expression of neuronal (dys-)function requires the knowledge of the exact composition of a vast pool of genes as well as the contributions of environmental factors.
Sets of genes affect whole networks of molecules and cells on the higher levels of organisation in ways as yet unknown, their impacts moving all the way up to cognition and behaviour. Therefore, if neuroscientists wish to understand what is going on when complex brain function is generated, they must undertake the arduous task of finding out how function is generated on each level of organisation and how it is transferred to the next higher one. This understanding rests on the insight originally expressed by David Marr and Werner Reichardt. It is now the mission of the CIN.
Last but not least, the methodological toolbox of molecular biology and genetics for assessing the function of molecules is vast (see: Genes and Molecules). These methods permit the measurement or manipulation of the function of single molecules and molecular signalling cascades. These methods can be targeted at single cells as well as at whole organisms. They thus cover measurements over a large range of temporal and spatial scales.