Multidisciplinary Studies on Excitatory Amino Acids as Transmitters in the Brain.
Abstract
Our major goal has been to analyze the excitatory amino acid receptors in the brain, particularly those mediating responses by glutamate and aspartate. Acidic amino acids, principally L-glutamate and L-aspartate, appear to be the major excitatory transmitters in the CNS. As such, these molecules may be the most abundant CNS neurotransmitter class. L-Glutamate shows many of the characteristics of other neurotransmitters. Glutamate is present in high levels in the brain and is relatively enriched in select neurons. Transmitter glutamate is supplied to nerve termials by synthesis, primarily via the enzyme glutaminase, and by high affinity uptake. The mechanism for transmitter inactivation in the synapse appears to be the rapid removal by a high affinity uptake system. Both endogenous L-glutamate and L-glutamate derived from exogenously supplied radiolabelled precursors exhibit Ca(++)- dependent release upon depolarization. A transport system responsible for the loading of L-glutamate into synaptic vesicles has also been identified. Excitatory amino acids act on a variety of distinct receptor types, and there are now available many compounds which can mimic or block synaptic activity at excitatory amino acid using synapses. Our approach has involved the analysis of these receptors in isolated synaptic membranes and their further definition and anatomical localization via light microscopic autoradiography.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 07, 1985
- Accession Number
- ADA164258
Entities
People
- Carl W. Cotman
Organizations
- University of California, Irvine