The sucrose intake changes stress-induced behavior via dysfunction of noradrenergic nervous system.

Abstract

Lifestyle habits have attracted attention as environmental factors of depression.

We analyzed lifestyle habits in high-risk subjects of major depressive disorder (HRMDD). In our analysis of lifestyle habits in HRMDD, we observed elevated sucrose intake.

To investigate how sucrose intake affects stress-induced depression-like behaviors, mice took sucrose liquid freely were subjected to chronic unpredictable mild stress (CUMS). The sucrose intake attenuated CUMS-induced hyperactivity and aggressive behavior but not social deficit. Unexpectedly, the sucrose intake under CUMS impaired recognition memory.

CUMS reduced noradrenaline (NA) tissue levels in the prefrontal cortex. Sucrose intake under CUMS conditions mitigated reduction in NA levels, although it slowed down the turnover of NA, which associated with a decrease in the expression of adrenergic α1 receptors and an increase in the expression of adrenergic α2 receptors.

In this study, it is suggested that increased sucrose intake in HRMDD serves to attenuate stress-induced aggression and hyperactivity. However, this comes with the unintended consequence of impairing cognitive function.These contradictory findings may be attributed to changes observed in NA tissue levels and receptor expression in prefrontal cortex.