ABSTRACT
Carbon fiber microelectrodes provide the ideal platform for performing ultrafast, selective measurements of electroactive brain molecules. This article highlights the current status of the use of carbon fiber microelectrodes in neurochemical measurements, outlining the most cutting edge findings and technological advances in amperometry and fast-scan cyclic voltammetry.
Subject(s)
Adenosine/analysis , Amines/analysis , Brain/metabolism , Carbon/chemistry , Hydrogen Peroxide/analysis , Oxygen/analysis , Signal Transduction , Adenosine/metabolism , Amines/metabolism , Animals , Brain/cytology , Carbon Fiber , Electrochemical Techniques/instrumentation , Humans , Hydrogen Peroxide/metabolism , Microelectrodes , Oxygen/metabolismABSTRACT
Dopamine and serotonin (5-hydroxytryptamine or 5-HT) are neurotransmitters that are implicated in many psychological disorders. Although dopamine transmission in the brain has been studied extensively in vivo with fast scan cyclic voltammetry, detection of 5-HT using in vivo voltammetric methods has only recently been established. In this work we use two carbon-fiber microelectrodes to simultaneously measure dopamine release in the nucleus accumbens and 5-HT release in the substantia nigra pars reticulata, using a common stimulation in a single rat. We find that 5-HT release is profoundly restricted in comparison with dopamine release despite comparable tissue content levels. Using physiological and pharmacological analysis, we find that 5-HT transmission is mostly sensitive to uptake and metabolic degradation mechanisms. In contrast, dopamine transmission is constrained by synthesis and repackaging. Finally, we show that disruption of serotonergic regulatory mechanisms by simultaneous inhibition of uptake and metabolic degradation can have severe physiological consequences that mimic serotonin syndrome.
