Impact of microdialysis probes on vasculature and dopamine in the rat striatum: a combined fluorescence and voltammetric study.
Measuring extracellular dopamine in the brain of living animals by means of microdialysis and/or voltammetry is a route towards understanding both normal brain function and pathology. Previous reports, however, suggest that the tissue response to implantation of devices may affect the outcome of the measurements. To address the source of the tissue response and its impact on striatal dopamine systems microdialysis probes were placed in the striatum of anesthetized rats. Images obtained by dual-label fluorescence microscopy show signs of ischemia and opening of the blood-brain barrier near the probe tracks. Opening of the blood-brain barrier was further examined by determining dialysate concentrations of carbi-DOPA, a drug that normally does not penetrate the brain. Although carbi-DOPA was recovered in brain dialysate, it did not alter dialysate dopamine levels or evoked dopamine release as measured by voltammetry near the probes. Microdialysis probes also significantly diminished the effect of intrastriatal infusion of kynurenate on extracellular dopamine levels as measured by voltammetry near the probes.
Mitala
Christina M
CM
Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, PA 15260, United States.
Wang
Yuexiang
Y
Borland
Laura M
LM
Jung
Moon
M
Shand
Stuart
S
Watkins
Simon
S
Weber
Stephen G
SG
Michael
Adrian C
AC
D000818:Animals; D002230:Carbidopa / Q000008:administration & dosage / Q000032:analysis; D002560:Cerebrovascular Circulation; D002851:Chromatography, High Pressure Liquid; D003342:Corpus Striatum / Q000098:blood supply* / Q000187:drug effects / Q000473:pathology*; D004298:Dopamine / Q000032:analysis*; D015259:Dopamine Agents / Q000008:administration & dosage / Q000032:analysis; D004567:Electrodes, Implanted / Q000009:adverse effects*; D018691:Excitatory Amino Acid Antagonists / Q000008:administration & dosage / Q000032:analysis; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D007276:Injections, Intraventricular; D007736:Kynurenic Acid / Q000008:administration & dosage / Q000032:analysis; D008297:Male; D017551:Microdialysis / Q000295:instrumentation*; D008839:Microelectrodes / Q000009:adverse effects*; D018613:Microscopy, Confocal; D053769:Nanocapsules / Q000008:administration & dosage / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley
D015259:Dopamine Agents; D018691:Excitatory Amino Acid Antagonists; D053769:Nanocapsules; D007736:Kynurenic Acid; D002230:Carbidopa; D004298:Dopamine