Amino acids in microdialysates

Since its development in the 1980’s, microdialysis has widely been used for in vivo measurement of neurotransmitters and neuromodulators at the locations where they are present.
Amino acids are not only the building blocks of proteins, but can also function as excitatory (e.g. Glu and Asp) and inhibitory (GABA) neurotransmitters, and have habitually been measured with microdialysis in several regions of the brain. Preceding narrative reviews have e.g. analysed the neuronal vs. glial origin of Glu and GABA in dialysates, or described the effects of anaesthesia on several amino acids in dialysates.
Microdialysis concentration measurements heavily depend on experimental factors such as the perfusion fluid running speed, the used membrane and the region of interest. Methods vary between research groups, which may result in differences in baseline values.
To date, no systematic review of the microdialysis technique has been published. This systematic review will map all published baseline amino acid concentrations in dialysate for the selected amino acids, and explore variability within and between research groups.