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Presynaptic glutamate receptors modulate dopamine release from striatal synaptosomes
1Program in Neurosciences, Tufts University School of Medicine, Boston, Massachusetts 02111.
Journal of Neurochemistry
|September 1, 1991
Summary
Presynaptic glutamate receptors on dopamine nerve terminals in the striatum control dopamine release. These receptors are pharmacologically similar to postsynaptic glutamate receptors, suggesting a role in neurotransmitter interactions.
Area of Science:
- Neuroscience
- Neurochemistry
Background:
- Glutamate's neuronal actions are primarily attributed to postsynaptic N-methyl-D-aspartate (NMDA) and non-NMDA receptors.
- The role of presynaptic glutamate receptors, particularly on dopaminergic terminals, remains less understood.
Purpose of the Study:
- To investigate the presence and function of presynaptic glutamate receptors on isolated striatal dopaminergic nerve terminals (synaptosomes).
- To characterize the pharmacological properties of these presynaptic receptors and their effect on dopamine release.
Main Methods:
- Utilized isolated striatal dopaminergic synaptosomes.
- Administered N-methyl-D-aspartate (NMDA) and non-NMDA agonists under specific ionic conditions (Mg2+, glycine).
- Assessed calcium-dependent dopamine release and the effects of selective receptor antagonists.
Main Results:
- Demonstrated the existence of functional presynaptic glutamate receptors on striatal dopaminergic terminals.
- NMDA and non-NMDA agonists stimulated calcium-dependent dopamine release.
- NMDA-stimulated release was blocked by Mg2+ and NMDA antagonists.
- Non-NMDA agonist-stimulated release was blocked by a non-NMDA antagonist but not by Mg2+ or NMDA antagonists.
Conclusions:
- Presynaptic glutamate receptors on striatal dopaminergic terminals are pharmacologically similar to their postsynaptic counterparts.
- These receptors modulate dopamine release, indicating a significant role in striatal neurotransmitter interactions.