ABSTRACT
Introduction .................................................................................................................................. 206
Overview ...................................................................................................................................... 206
Physiology of DA Release: Why It Can Be Detected in the Extracellular Space ................. 206
A Brief History of In Vivo and In Vitro Voltammetry ....................................................... 208
Advantages of Brain Slices to Study DA Release .................................................................. 209
Voltammetric Methods ................................................................................................................. 210
Comparison of Voltammetric Techniques ............................................................................... 210
Constant Potential Amperometry ......................................................................................... 211
Chronoamperometry ............................................................................................................. 211
Fast-Scan Cyclic Voltammetry ............................................................................................ 212
Electrodes ................................................................................................................................. 214
Brain Slice Methodology ............................................................................................................. 214
aCSF Composition for Healthy Slices ..................................................................................... 216
Species Selection ...................................................................................................................... 217
Plane of Slicing ........................................................................................................................ 217
Stimulating and Recording DA Release in Brain Slices ............................................................. 219
Signal versus Interference ........................................................................................................ 220
Regulation of Striatal DA Release by H
O
............................................................................... 221
Endogenous H
O
Inhibits Axonal DA Release ..................................................................... 222
Potential Sources of H
O
Generation..................................................................................... 222
Regulation of Axonal DA Release by Glutamate Acting at AMPA
Receptors Requires H
O
..................................................................................................... 222
Activity-Dependent H
O
Generation in Striatal Medium Spiny Neurons ............................ 224
H
O
Acts via K
Channels to Inhibit DA Release ............................................................ 225
Summary and Future Directions for Studies of H
O
as a Neuromodulator.............................. 225
Acknowledgments ........................................................................................................................ 226
References .................................................................................................................................... 226
Reactive oxygen species (ROS) are often considered to be toxic byproducts of cell metabolism.
Increased ROS production and oxidative stress contribute to cell death after acute brain injury, as
well as in slowly progressing neurodegenerative disorders, including Parkinson’s disease [1,2].
However, this view of ROS is rapidly evolving in light of increasing evidence that ROS also act as
cellular messengers that can modulate processes from short-term ion-channel activation to gene
transcription. Hydrogen peroxide (H
