Related Experiment Videos
Behavioral and biochemical changes following acute administration of MPTP and MPP+
Abstract:
The acute effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 1-methyl-4-phenylpyridinium ion (MPP+) on mouse locomotor activity and striatal dopamine (DA) and 5-hydroxytryptamine (5-HT) levels were investigated. A single dose of either MPTP (10-30 mg/kg, i.p.) or MPP+ (5-20 ug/mouse, i.c.v.) decreased locomotor activity 10-40 min after injection: this locomotor effect was significantly suppressed by either pretreatment with nomifensine or 1-deprenyl alone, or by the combination of desmethylimipramine and 6-hydroxydopamine. Pretreatment with clorgyline did not suppress this behavior and a single dose of haloperidol enhanced the effect. The striatal levels of DA, 3-methoxytyramine and 5-HT increased in parallel with the decrease in locomotor activity caused by MPTP or MPP+. In contrast, levels of 3,4-dihydroxyphenylacetic acid, homovanillic acid and 5-hydroxyindoleacetic acid were decreased by injection of either MPTP or MPP+. Possible mechanism(s) of the behavioral and biochemical changes caused by the acute actions of MPTP and MPP+ with respect to their neurotoxic effects on the nigrostriatal DA system are discussed.
Insights
The neurotoxins 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 1-methyl-4-phenylpyridinium ion (MPP+) reduce mouse movement and alter dopamine levels. Their effects on locomotor activity are modulated by specific drug pretreatments.
Area of Science:
- Neuroscience
- Pharmacology
Background:
- 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and its metabolite 1-methyl-4-phenylpyridinium ion (MPP+) are known neurotoxins.
- MPTP and MPP+ are frequently used to model Parkinson's disease in research settings.
- Investigating the acute effects of these compounds is crucial for understanding neurotoxic mechanisms.
Purpose of the Study:
- To investigate the acute effects of MPTP and MPP+ on mouse locomotor activity.
- To examine the impact of MPTP and MPP+ on striatal dopamine (DA) and 5-hydroxytryptamine (5-HT) levels.
- To explore the neurochemical mechanisms underlying the behavioral and biochemical changes induced by MPTP and MPP+.
Main Methods:
- Mice were administered single doses of MPTP (i.p.) or MPP+ (i.c.v.).
- Locomotor activity was measured 10-40 minutes post-injection.
- Striatal levels of DA, 5-HT, and their metabolites were analyzed biochemically.
- The effects of various drug pretreatments (nomifensine, 1-deprenyl, desmethylimipramine, 6-hydroxydopamine, clorgyline, haloperidol) were assessed.
Main Results:
- Both MPTP and MPP+ significantly decreased locomotor activity.
- This locomotor depression was attenuated by nomifensine, 1-deprenyl, and a combination of desmethylimipramine and 6-hydroxydopamine.
- Clorgyline did not suppress the effect, while haloperidol enhanced it.
- Striatal DA and 5-HT levels increased, while their metabolites decreased, in parallel with reduced locomotor activity.
Conclusions:
- Acute administration of MPTP and MPP+ causes significant behavioral and biochemical alterations in mice.
- The observed effects are related to the disruption of the nigrostriatal dopamine system.
- Drug pretreatments highlight the complex interplay of neurotransmitter systems in MPTP/MPP+-induced neurotoxicity.