Dehydroepiandrosterone increases tonic and phasic dopamine release in the striatum

Area of Science:

• Neuroscience
• Pharmacology
• Endocrinology

Background:

• Dehydroepiandrosterone (DHEA) is known to modulate dopaminergic neurotransmission.
• DHEA's role in neurologic and psychiatric disorders involving monoamine neurotransmitters is significant.
• Previous studies on DHEA's effect on dopamine release have yielded contradictory results.

Purpose of the Study:

• To investigate the precise effects of DHEA on striatal dopamine release and metabolism.
• To examine the relationship between DHEA administration, dopamine levels, and motor activity.
• To clarify the seemingly paradoxical effects of DHEA on dopamine release and behavior.

Main Methods:

• In vivo microdialysis was employed in male Wistar rats with cannulas implanted in the striatum.
• DHEA was administered at 120 mg/kg, with dialysates collected over 280 minutes.
• High-Performance Liquid Chromatography with Electrochemical Detection (HPLC-ED) was used to analyze dopamine and its metabolites.

Main Results:

• Extracellular dopamine concentrations were elevated in DHEA-treated rats both before and after depolarization.
• DHEA administration led to a reduction in the areas under the curve for dopamine metabolites and DA/metabolite ratios.
• A notable decrease in motor activity was observed in DHEA-treated rats, particularly within the first 20 minutes post-administration.

Conclusions:

• DHEA exerts a stimulatory effect on striatal dopamine release.
• This increased dopamine release was not mirrored by changes in dopamine metabolism or overall motor activity.
• DHEA's action, increasing dopamine release while reducing behavioral activation, is comparable to the effects of typical antipsychotic medications.