ABSTRACT
Dialysis is a process of passive diffusion of solute across a semipermeable membrane. In vivo microdialysis is essentially a dialysis procedure, but miniaturized to allow continuous sampling of molecules from extracellular fluid of animals and man. An advantage of microdialysis for studies of brain chemistry is that the technique allows continuous sampling of low-molecular-weight substances in the extracellular fluid. Microdialysis probes are placed in the tissue of choice using various techniques. Their placement in the brain is quite similar to that of electrodes or injection cannulae. Microdialysis courses are offered by all leading vendors of microdialysis equipment on a regular basis. The most common way of accomplishing a continuous perfusion of the medium for microdialysis is using perfusion pumps. Microdialysis is a very valuable and increasingly utilized technique for studying epilepsy. It allows continuous sampling of extracellular fluid for solutes, including neurotransmitters, cellular metabolites, ions, and drugs.
