Neuroendocrine stress responses predict catecholamine-dependent working memory-related dorsolateral prefrontal cortex...

Area of Science:

• Neuroscience
• Psychoneuroendocrinology
• Cognitive Psychology

Background:

• Acute stress impacts higher-order cognitive functions, notably working memory, primarily via central catecholamine activity.
• The relationship between neuroendocrine stress responses and catecholamine-dependent working memory function, particularly in non-stressful states, remains poorly understood.

Purpose of the Study:

• To investigate the association between neuroendocrine stress responses (cortisol, alpha-amylase) and working memory-related brain activity.
• To examine how these relationships are modulated by atomoxetine, a noradrenaline transporter inhibitor, in healthy humans.

Main Methods:

• 18 healthy human participants underwent stress induction and received atomoxetine or placebo.
• Neuroendocrine responses (cortisol, alpha-amylase) and fronto-parietal working memory activity (fMRI) were measured.
• Correlations between stress markers and brain activity changes were analyzed.

Main Results:

• Positive correlations were found between stress-induced cortisol and alpha-amylase levels and working memory activity in the dorsolateral prefrontal cortex.
• Cortisol increases also correlated with working memory activity in the supramarginal gyrus.
• High stress responders exhibited reduced working memory activity with placebo and enhanced activity with atomoxetine compared to low responders.

Conclusions:

• Neuroendocrine stress responses serve as a proxy for catecholamine function relevant to higher-order cognitive processes like working memory.
• Findings suggest a complex interplay between acute stress, catecholamine systems, and working memory capacity.