Related Experiment Videos
Selective MPP+ uptake into synaptic dopamine vesicles: possible involvement in MPTP neurotoxicity
M Del Zompo1, M P Piccardi, S Ruiu
1Department of Neuroscience B. Brodie, University of Cagliari, Italy.
British Journal of Pharmacology
|June 1, 1993
Summary
Researchers found that the toxin 1-methyl-4-phenylpyridinium ion (MPP+) is taken up by synaptic vesicles in mouse striatum, suggesting it shares a carrier with dopamine. This uptake is specific to dopamine-rich brain regions.
Area of Science:
- Neuroscience
- Neuropharmacology
- Molecular Biology
Background:
- The mechanism of dopamine transport into synaptic vesicles is crucial for neurotransmission.
- 1-methyl-4-phenylpyridinium ion (MPP+) is a neurotoxin implicated in Parkinsonism, known to accumulate in dopaminergic neurons.
Purpose of the Study:
- To investigate the mechanism and specificity of MPP+ uptake into synaptic vesicles.
- To determine if MPP+ shares a transport system with dopamine.
Main Methods:
- Studied the saturable, Mg2+/ATP-, and temperature-dependent uptake of MPP+ in synaptic vesicles isolated from mouse striatum.
- Investigated the sensitivity of MPP+ uptake to tetrabenazine, dopamine, and amphetamine.
- Examined the regional distribution of MPP+ uptake in various mouse brain regions.
Main Results:
- MPP+ uptake into striatal synaptic vesicles is saturable and dependent on Mg2+/ATP and temperature.
- MPP+ uptake is inhibited by tetrabenazine, dopamine, and amphetamine, suggesting shared carrier mechanisms with dopamine.
- MPP+ uptake is predominantly found in dopamine-rich regions (striatum, olfactory tubercles, hypothalamus) and absent in dopamine-poor regions (cerebellum, cortex, pons-medulla).
- This region-specific uptake indicates MPP+ as a marker for the dopamine vesicular transporter.
Conclusions:
- Dopamine and MPP+ share a common vesicular transporter in the striatum.
- The differential distribution of MPP+ uptake highlights regional variations in monoamine vesicular carriers.
- MPP+ uptake and vesicular storage may play a role in the neurotoxicity of MPP+ in dopaminergic neurons.