Real-time measurement of dopamine fluctuations after cocaine in the brain of behaving rats.
Dopamine neurotransmission has been implicated in the modulation of many cognitive processes. Both rapid (phasic) and slower (tonic) changes in its extracellular concentration contribute to its complex actions. Fast in vivo electrochemical techniques can measure extracellular dopamine on a rapid time scale but without the selectivity afforded with slower techniques that use chemical separations. Cyclic voltammetry improves chemical resolution over other electrochemical methods, and it can resolve dopamine changes in the brains of behaving rodents over short epochs (<10 s). With this method, however, selective detection of slower dopamine changes is still elusive. Here we demonstrate that principal component regression of cyclic voltammetry data enables quantification of changes in dopamine and extracellular pH. Using this method, we show that cocaine modifies dopamine release in two ways: dopamine concentration transients increase in frequency and magnitude, whereas a gradual increase in steady-state dopamine concentration occurs over 90 s.
Heien
Michael L A V
ML
Department of Chemistry and Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599-3290, USA.
Khan
Amina S
AS
Ariansen
Jennifer L
JL
Cheer
Joseph F
JF
Phillips
Paul E M
PE
Wassum
Kate M
KM
Wightman
R Mark
RM
D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism*; D003042:Cocaine / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism*; D004563:Electrochemistry; D045604:Extracellular Fluid / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D025341:Principal Component Analysis; D051381:Rats; D012044:Regression Analysis; D013997:Time Factors
D003042:Cocaine; D004298:Dopamine