The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Glutamate, but not aspartate, is enriched in trigeminothalamic tract terminals and associated with their synaptic vesicles in the rat nucleus submedius.

På svenska

Author

  • Stefan Persson
  • Jonas Broman

Summary, in English

To examine the possible roles of glutamate and aspartate as neurotransmitters in the nucleus submedius (Sm) of rats, the distributions of these amino acids were examined by electron microscopic immunogold labeling. High levels of glutamate were detected in trigeminothalamic tract terminals anterogradely labeled with horseradish peroxidase conjugates. These terminals also displayed a positive correlation between the densities of synaptic vesicles and gold particles signaling glutamate. In contrast, aspartate levels in such terminals were low and displayed no correlation with the density of synaptic vesicles. Terminals of presumed cortical origin contained the highest estimated levels of glutamate, but the positive correlation between glutamate signal and synaptic vesicle density did not reach statistical significance, presumably due to technical factors. The latter terminals also contained relatively high levels of aspartate, though without any correlation to synaptic vesicle density. The present findings provide strong support for glutamate, but not aspartate, as a trigeminothalamic tract neurotransmitter responsible for the fast synaptic transmission of nociceptive signals to neurons in the rat nucleus submedius. Aspartate presumably serves metabolic roles in these terminals. With respect to terminals of presumed cortical origin, our data are not at odds with the notion that also these terminals use glutamate as their neurotransmitter. Our findings do not support a neurotransmitter role for aspartate in the latter terminals, although such a role cannot be entirely refuted.

Department/s

Publishing year

2004

Language

English

Pages

152-161

Publication/Series

Experimental Brain Research

Volume

157

Issue

2

Document type

Journal article

Publisher

Springer

Topic

  • Neurosciences

Keywords

  • thalamus
  • immunogold
  • somatosensory
  • pain
  • excitatory amino acids

Status

Published

Research group

  • Neurophysiology

ISBN/ISSN/Other

  • ISSN: 0014-4819