EFFECTS OF DIFFERENT PERFUSION MEDIUM ON THE EXTRACELLULAR BASAL CONCENTRATION OF DOPAMINE IN STRIATUM AND MEDIAL PREFRONTAL CORTEX - A ZERO-NET FLUX MICRODIALYSIS STUDY

The zero-net flux microdialysis method was used to determine (1) the b asal concentration of dopamine (DA) in the extracellular space, and (2 ) the in vivo recovery of DA in the striatum and the medial prefrontal cortex by using three different kinds of perfusion medium. They were, (a) commercial Ringer's solution, (b) low Ca2+ Ringer's solution, and (c) artificial cerebrospinal fluid (aCSF). Our results not only suppo rt previous findings that the high Ca2+ concentration in the perfusion medium could increase the baseline concentration of DA in the dialysa te, which was collected from extracellular space through dialysis prob e; but also provides evidence that this baseline increase was primaril y due to an increase of basal DA concentration, and not from the incre ase of the in vivo recovery. Additionally, there was no significant di fference in the basal DA concentration by using either commercial Ring er's solution or aCSF. This indicates that both commercial Ringer's so lution and aCSF are suitable as good perfusion medium to determine the basal DA in the rat's brain. (C) 1997 Elsevier Science Ireland Ltd.