Differential effects of post-implantation time on potassium- versus D-amphetamine-evoked dopamine overflow in the striatum of F344 rats.
Effects of post-implantation time on potassium (K+)- versus D-amphetamine (D-AMPH)-evoked striatal dopamine (DA) overflow were measured using microdialysis in freely moving young and aged Fischer 344 rats. In one group, samples were collected on the day of probe insertion (Day 1 group). In a second group, samples were collected 24 h after probe insertion (Day 2 group). While analyses revealed no significant differences between the two age groups, the 100 mM K+ stimulus evoked a significantly greater amount of DA overflow in the Day 1 group compared to the Day 2 group. The decrease in 3,4-dihydroxyphenylacetic acid (DOPAC) produced by K+ stimulation was not influenced by post-implantation time. The effect of the 250 microM D-AMPH stimulus on DA overflow did not differ between the Day 1 and Day 2 groups, nor did the decrease in DOPAC that accompanied D-AMPH stimulation. These results support the hypothesis that under some stimulus conditions, post-implantation time is an important variable in microdialysis studies.
Purdom
Matthew S
MS
Department of Anatomy and Neurobiology, 306 Davis Mills Building, University of Kentucky, Lexington, KY 40536-0098, USA.
Stanford
John A
JA
Gerhardt
Greg A
GA
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000375:Aging / Q000378:metabolism*; D000818:Animals; D003913:Dextroamphetamine / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism*; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D017551:Microdialysis / Q000295:instrumentation / Q000379:methods*; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism*; D009434:Neural Pathways / Q000187:drug effects / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology*; D051381:Rats; D011916:Rats, Inbred F344; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology*; D013378:Substantia Nigra / Q000187:drug effects / Q000378:metabolism
D015102:3,4-Dihydroxyphenylacetic Acid; D011188:Potassium; D003913:Dextroamphetamine; D004298:Dopamine