ABSTRACT
Introduction to Dopamine Neurotransmission ............................................................................. 337
Electrochemical Detection of DA ............................................................................................ 338
Quantal DA Release ................................................................................................................. 338
Source of DA Neurons: Selection of Animals and Brain Regions ......................................... 339
Methods ........................................................................................................................................ 340
Preparation of Glass Coverslips ............................................................................................... 341
Preparation of Pipette “Tech-Tips” for Triturating Cells ........................................................ 342
SYLGARD Circles ................................................................................................................... 342
Glia (Using Rat Pups) .............................................................................................................. 342
DA Neurons .............................................................................................................................. 343
Media and Reagents ................................................................................................................. 349
Carbon Fiber Amprometry ....................................................................................................... 349
Electrode Fabrication ........................................................................................................... 349
Testing and Selection of Electrodes .................................................................................... 350
Recording.............................................................................................................................. 350
Analysis ................................................................................................................................ 351
References .................................................................................................................................... 351
Dopamine (DA) was discovered as the precursor of the neurotransmitter norepinephrine in 1957
(Montagu 1957). Carlsson demonstrated that DA levels in the striatum were much higher than in the
rest of the brain despite its low level of norepinephrine, suggesting that DA was not merely a
norepinephrine precursor but was itself a neurotransmitter (1959) (Carlsson 1959). Subsequently,
DA’s role as a neurotransmitter has been confirmed and populations of DA neurons have been
identified in various regions of the central nervous system (olfactory bulb, substantia nigra, ventral
tegmental area, and the retina) and the periphery (enteric nervous system of the gut). These neurons
are involved in modulating intestinal motility, the sense of smell, light sensitivity, and control of
fine motor movements. They are also integral to higher brain functions such as salience, euphoria,
pleasure and appetitive and consummatory aspects of reward. Their demise or dysfunction plays
vital roles in neuropathologies such as Parkinson’s disease, schizophrenia and depression.
Thus, understanding how DA neurons function normally in neurotransmission and in pathological
processes is essential for elucidating their roles in behavior and disease.
