Use of non-radioactive probes for mRNA detection by in situ hybridization: interests and applications in the central nervous system.

Non-radioactive probes for in situ hybridization (ISH) are now widely used to detect mRNAs in the central nervous system (CNS) using light and electron microscopy. Many different protocols for the detection of biotinylated or digoxigenin-labelled probes are now available. The advantages and inconveniences of the use of the non-radioactive probes are reviewed in the current work. These aspects are illustrated by some results from first-hand experience in the field of ISH to analyse gene expression and neuronal phenotypes in the hypothalamus and the basal ganglia. A very sensitive procedure for the simultaneous detection of two mRNAs with cRNA probes have been detailed and using in particular digoxigenin-labelled probes.