Chapter 3.3 Improvement of the temporal resolution of brain microdialysis: sampling in seconds

Abstract Brain microdialysis could provide better insight into brain functions on the condition that its temporal resolution could be improved. Such endeavor requires the creation of analytical techniques that are able to analyze samples whose volumes are in the order of a few nanoliters. In addition, it requires the creation of laboratory methods to handle, in a reproducible manner, nanoliter volumes. In the present chapter, the progress made in both areas during the last 10 years is reviewed. The methods invented so far include capillary-zone electrophoresis with laser-induced fluorescence detection, nanoliter volume reactors, assay tubes that allow carrying out chemical reactions in such volumes, and automatic injection systems to load picoliter volumes. Evidences that it is currently possible to lower the time resolution of brain microdialysis to a few seconds are presented. This chapter also discusses the way in which the improvement of the temporal resolution is influencing the interpretation of some of the neurochemical phenomena so far studied with brain microdialysis.