Single Photon Emission Computed Tomography Imaging of Dopaminergic Function: Presynaptic Transporter, Postsynaptic Receptor, and “Intrasynaptic” Transmitter
Year: 1997
Type: book-chapter
Abstract: Publisher Summary A promising single photon emission computed tomography (SPECT) radiotracer—[ 123 I] β -CIT (2 β -carbomethoxy-3 β -(4-iodophenyl) tropane—have been developed that labels DA transporters (DATs), which are located on the terminals of DA neuronal projections from the substantia nigra to the striatum. Thus, this tracer is a marker for the neurons that degenerate in Parkinson's disease (PD). This chapter reviews studies with [ 123 I] β -CIT, which suggest it is likely to be a useful as a research and potential clinical imaging to measure dopaminergic terminal innervation of the striatum. Neuroreceptor imaging can be used not only to quantify the target receptor, but also to assess changes in the synaptic concentration of neurotransmitter following pharmacological challenges. This chapter reviews the development and validation of a SPECT paradigm designed to provide, in the same experiment, a measure of the baseline D2-binding potential (BP) and of the reduction in D2 BP induced by amphetamine, which is an indirect measure of an amphetamine-induced increase in synaptic DA concentration. D-Amphetamine challenge studies in conjunction with SPECT imaging of the D2 receptor have been performed in human subjects. A bolus plus constant infusion administration schedule of the D2-receptor radiotracer [ 123 I]IBZM was used to obtain a stable baseline for reliable quantitation of the d -amphetamine effect. These studies show the feasibility of using [ 123 I]IBZM programmed infusion and SPECT imaging to measure endogenous DA release after d -amphetamine challenge and to study brain neurochemical correlates of emotions.
Source: Advances in pharmacology
Author: R B Innis
Institution: Yale University
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Funder: Yale University
OpenAlex ID: W1887859818