V and was initially to positive potentials. The upper cyclic voltammogram was obtained by subtracting the average of five scans immediately following the first stimulus pulse from the average of five scans during the baseline preceding the stimulus pulse. The lower cyclic voltammogram was obtained by subtracting the average of five scans 13 s after the stimulus was applied from the average of five scans obtained during the prestimulus baseline. (Reproduced from Neuroscience with permission [17].)

doi:10.1201/9780203908907-113

Chapter

V and was initially to positive potentials. The upper cyclic voltammogram was obtained by subtracting the average of five scans immediately following the first stimulus pulse from the average of five scans during the baseline preceding the stimulus pulse. The lower cyclic voltammogram was obtained by subtracting the average of five scans 13 s after the stimulus was applied from the average of five scans obtained during the prestimulus baseline. (Reproduced from Neuroscience with permission [17].)

Chapter

V and was initially to positive potentials. The upper cyclic voltammogram was obtained by subtracting the average of five scans immediately following the first stimulus pulse from the average of five scans during the baseline preceding the stimulus pulse. The lower cyclic voltammogram was obtained by subtracting the average of five scans 13 s after the stimulus was applied from the average of five scans obtained during the prestimulus baseline. (Reproduced from Neuroscience with permission [17].)

ABSTRACT

Autoreceptors are found at the terminals of presynaptic neurons and provide feed-back to these neurons. An autoreceptor responds to the neurotransmitter released by that neuron and can greatly influence neurotransmission. They are capable of controlling the concentration profile and lifetime of neurotransmitters in the synapse by modulating release [51, 52] or uptake [53-56]. Regulation of release can be broken into two subcategories: synthesis regulation and secretion regulation. This down-regulation of DA concentration within the extracellular fluid (fluid that fills the space between neurons) caused by autoreceptor activation is thought to prevent an over-stimulation of the postsynaptic receptors. Autorecep-tors typically have a much higher affinity for the neurotransmitter than the post-synaptic receptors. The multiple functionalities of receptors are thought to be a result of localization and intracellular coupling.