The principle of mRNA and protein profiling is to identify genes that are differentially expressed in selected tissues of cases and (matched) controls. One of the promising strategies is the use of human post-mortem brain tissues, from which nowadays good quality mRNA can be extracted for microarray analysis [7]. However, when performing such studies one has to be aware of the possibility that the differential expression could be caused by years of medicine usage or by pre- or post-mortem artifacts.
