Related Experiment Videos
Catecholamine synthesis in rat brain after axotomy: interaction between apomorphine and haloperidol
Naunyn-Schmiedeberg'S Archives of Pharmacology
|March 29, 1977
Summary
Cerebral hemitransection reveals a local feedback mechanism controlling dopamine synthesis. Dopamine synthesis is regulated locally, even without nerve impulses, suggesting receptor-mediated control.
Area of Science:
- Neuroscience
- Neurochemistry
- Pharmacology
Background:
- Ascending monoaminergic fibers play a crucial role in dopamine regulation.
- Understanding dopamine synthesis control is vital for neurological research.
Purpose of the Study:
- To investigate the role of local feedback mechanisms in dopamine synthesis following axotomy.
- To examine the effects of apomorphine and haloperidol on dopamine synthesis in lesioned and intact brain regions.
Main Methods:
- Cerebral hemitransection was performed to axotomize monoaminergic fibers.
- Aromatic amino acid decarboxylase was inhibited using 3-hydroxybenzylhydrazine HCl.
- Dopa accumulation was measured after administration of apomorphine and haloperidol.
- Dopamine and noradrenaline concentrations were analyzed in various brain structures.
Main Results:
- Axotomy stimulated dopa formation in the striatum and limbic system, indicating ongoing synthesis.
- Apomorphine antagonized dopa accumulation, while haloperidol stimulated it, suggesting receptor involvement.
- Haloperidol counteracted apomorphine's inhibitory effect, further supporting receptor-mediated control.
- Dopamine levels were slightly higher in the lesioned striatum, and noradrenaline decreased post-hemitransection.
Conclusions:
- The findings support a local, receptor-mediated feedback mechanism controlling dopamine synthesis, independent of impulse flow.
- This mechanism appears to regulate dopamine production even after significant axonal damage.