Achieving High Temporal Resolution for In Vivo Measurements by Microdialysis

Most methods for analyzing microdialysis samples require 1–20-min fraction collection times and off-line analysis of 1–50 min per sample; however, it is important to improve the temporal resolution to measure fast neurochemical events that go unnoticed with slower analyses. For example, many behavioral or pharmacological studies induce neurochemical release on the timescale of seconds or less. To better understand neurotransmitter release dynamics, there is a need to analyze microdialysis samples collected at shorter intervals. On-line analysis with fast analysis is a convenient way to avoid collecting many low-volume fractions. Capillary electrophoresis coupled with laser-induced fluorescence is a technique that allows for rapid measurements of neurochemicals. Separation times of 11 s can be achieved to measure GABA, taurine, serine, glycine, glutamate, and aspartate.