ABSTRACT
What Is Somatodendritic Dopamine Release? ............................................................................ 126
Midbrain Dopamine Neurons Release Dopamine from Their Somatodendrites .................... 126
The Functions and Sites of Action of Somatodendritic Dopamine ........................................ 126
Methodological Approaches to the Study of Somatodendritic Dopamine Release .................... 126
Electrochemical and Other Approaches to Dopamine Detection ........................................... 126
Co-Detection of DA and 5-HT in Midbrain ............................................................................ 127
FCV Waveform Choice........................................................................................................ 127
Species Variation in 5-HT Interference ............................................................................... 129
Characteristic Voltammetric and Pharmacological Differences.......................................... 130
In Vitro Methods for FCV in Midbrain ................................................................................... 130
Slice Preparations and Species............................................................................................. 130
Solutions ............................................................................................................................... 131
Scan Waveforms................................................................................................................... 131
Carbon-Fiber Microelectrodes: Preparation, Calibration .................................................... 133
Choice of Stimulation Parameters ....................................................................................... 133
Concerns in Signal Identification ......................................................................................... 135
What Is the Mechanism of Release? ........................................................................................... 136
Anatomical Evidence ............................................................................................................... 136
Mechanistic Evidence............................................................................................................... 136
Regulation of Somatodendritic Dopamine Signals by Extracellular Geometry and Uptake ..... 137
Volume Transmission and Uptake ........................................................................................... 137
Regional Kinetic Distinctions .................................................................................................. 138
Neuromodulation of Somatodendritic Release ............................................................................ 139
Autoreceptor Regulation .......................................................................................................... 139
Heteroreceptor and Other Neuromodulatory Regulation ........................................................ 140
Summary and Conclusions ........................................................................................................... 141
Acknowledgments ........................................................................................................................ 142
References .................................................................................................................................... 142
Midbrain dopamine (DA) neurons of the substantia nigra (SN, “A9”) and adjacent ventral
tegmental area (VTA, “A10”) are critical to a range of CNS functions, including motor facilitation
by the basal ganglia and the regulation of motivation by natural rewards as well as by drugs of
addiction. A characteristic shared by DA cells in the SN and VTA is that they release DA locally
from somatodendritic regions
as well as from their axonal projections. There is evidence for
release from soma
as well as from dendrites.
