Related Experiment Videos
Dopamine-mediated increases in nigral substance P-like immunoreactivity
Biochemical Pharmacology
|September 1, 1985
Summary
Methamphetamine increases substance P-like immunoreactivity (SPLI) in the substantia nigra via dopaminergic activity, not serotonergic. Dopamine uptake blockers mimicked this effect, but through different mechanisms than methamphetamine.
Area of Science:
- Neuroscience
- Pharmacology
Background:
- Methamphetamine (METH) affects neurotransmitter systems.
- Substance P-like immunoreactivity (SPLI) is altered by METH in the substantia nigra.
Purpose of the Study:
- To investigate the role of dopaminergic and serotonergic activity in METH-induced SPLI changes.
- To compare the mechanisms of dopamine uptake blockers and METH on the striatonigral SP pathway.
Main Methods:
- Treatment of rats with dopamine (DA) uptake blockers (amfonelic acid, nomifensine) and serotonin uptake blockers (citalopram, chlorimipramine).
- Measurement of SPLI levels in the substantia nigra.
- Assessment of monoaminergic synthesizing enzymes (tyrosine hydroxylase, tryptophan hydroxylase).
- Effect of reserpine pretreatment on SPLI.
Main Results:
- Dopamine uptake blockers, like METH, increased nigral SPLI.
- Serotonin uptake blockers did not affect SPLI.
- Dopamine uptake blockers altered SP without affecting synthesizing enzymes, unlike METH.
- Reserpine abolished the effect of amfonelic acid but not METH on SPLI.
Conclusions:
- Increased dopaminergic activity, not serotonergic, mediates METH-induced SPLI increases.
- Dopamine uptake blockers and METH influence the striatonigral SP pathway via distinct mechanisms.