Retro-dialysis

To date, few detection methods are available for analysis of purine molecules in brain microdialysis samples. Most methods infuse purine molecules (retro-dialysis) directly to a brain region of interest then examine alterations in baseline levels of other neurotransmitters, such as DA [150]. When ATP or adenosine is detected in the brain using microdialysis, the dialysate samples are separated and detected by LC connected to either UV absorbance or fluorescence [72—76]. Striatal baseline levels of adenosine have been reported between 40 and 210 nM in the rat, while striatal ATP levels in the mouse are 60—170 nM using chemiluminescence [165]. What is most striking about extracellular adenosine and ATP measurements are the large basal ranges reported, which may be due to differences in LC methods, detector sensitivity, or the derivatiza-tion step required for fluorescence detection. 

Nattie E, Shi J, Li A. 2001. BicucuUine dialysis in the retro-trapezoid nucleus (RTN) region stimulates breathing in the awake rat. Respir Physiol 124 179-193. 

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