Microdialysis Coupled with Electrochemical Detection: A Way to Investigate Brain Monoamine Role in Freely Moving Animals

Microdialysis technique coupled with electrochemical detection (ED) is a relatively new method that allows detection of neurotransmitters and other substances from brain and other tissues. It is based on the insertion of a dialysis probe in a specific area and perfusing it with artificial cerebrospinal fluid (CSF), which, passing in a chamber delimited by the dialysis fiber, becomes enriched with small molecular weight substances diffusing into the fiber because of their concentration gradient. Substances recovered can be assayed by high-performance liquid chromatography (HPLC) to evaluate their concentration in the dialysate, that is closely related to their extracellular concentration in the area investigated. After recovery from surgery, therefore, the effects of drugs or other treatments on the assayed substance can be evaluated in freely moving animals (1 ).