Changes in striatal dopamine transporter and tyrosine hydroxylase expression associated with fatigue and their reversal by blueberry juice

Abstract

BACKGROUND:

Blueberry juice is a common drink for relieving fatigue, but its mechanisms of action are unclear.

OBJECTIVE:

This study aimed to validate changes in the dopaminergic system, especially changes in dopamine transporter (DAT) levels, in a fatigued state and assess whether such fatigue-related changes can be ameliorated by blueberry juice.

METHODS:

We investigated the expression of striatal DAT and tyrosine hydroxylase (TH) in mice subjected to a forced swimming fatigue task and subsequently administered blueberry juice (anthocyanin), caffeine, or Red Bull (caffeine + taurine) to assess DAT and TH changes in the nigrostriatal pathway related with fatigue as well as their relief.

RESULTS:

Striatal DAT and TH expression was downregulated by fatigue and upregulated by treatment with blueberry juice, caffeine, and Red Bull. In addition, DAT and TH expression exhibited positive correlations with fatigue-related motor performance.

CONCLUSIONS:

We provided evidence of compensatory responses of striatal DAT and TH in the fatigued state, and treatments to relieve fatigue might upregulate the expression of both striatal DAT and TH. Moreover, small amounts of blueberry juice exerted similar effects as large amounts, suggesting that anthocyanin has relatively strong anti-fatigue effects.