The association between cingulate cortex glutamate concentration and delay discounting is mediated by resting state...

Area of Science:

• Neuroscience
• Psychology
• Psychiatry

Background:

• Individual differences in delaying gratification, or delay discounting, are stable psychological traits.
• Impulsive decision-making is a hallmark of various psychiatric disorders.
• Intrinsic brain functioning may predict individual differences in delay discounting.

Purpose of the Study:

• To investigate if intrinsic brain functioning predicts delay discounting.
• To explore the relationship between delay discounting and resting-state activity in the dorsal anterior cingulate cortex (dACC).

Main Methods:

• Fourteen healthy males completed a delay discounting task.
• Resting-state functional magnetic resonance imaging (fMRI) assessed brain connectivity.
• Magnetic resonance spectroscopy (¹H MRS) measured dACC glutamate concentrations.

Main Results:

• Delay discounting correlated with dACC glutamate levels.
• Delay discounting was associated with dACC functional connectivity to midbrain regions (ventral tegmental area, substantia nigra).
• Midbrain functional connectivity mediated the relationship between dACC glutamate and delay discounting.

Conclusions:

• Intrinsic properties of the dACC, including glutamate concentration and functional connectivity, predict individual differences in delay discounting.
• These findings highlight potential neural biomarkers for impulsive decision-making relevant to psychiatric disorders.