mRna expression analysis of tissue sections and single cells

Thirty years of literature have shown that changes in mRNA abundance provide insight into cellular functioning. Indeed, mRNA abundance measurements have been used to determine how effective particular drugs are in eliciting cellular responses, in monitoring behavioral responses, and in several other areas of neurobiology. Although investigation of individual mRNAs was informative, there are many thousands of mRNAs expressed in individual cells at varying abundances, the combination of which gives rise to cellular functioning. The advent of high-density cDNA arrays has greatly facilitated the ability to simultaneously examine the abundances of multiple mRNAs.