Functional and neurochemical interactions within the amygdala-medial prefrontal cortex circuit and their relevance to emotional processing

Brain Struct Funct. 2017 Apr;222(3):1267-1279. doi: 10.1007/s00429-016-1276-z. Epub 2016 Aug 26.


The amygdala-medial prefrontal cortex (mPFC) circuit plays a key role in emotional processing. GABA-ergic inhibition within the mPFC has been suggested to play a role in the shaping of amygdala activity. However, the functional and neurochemical interactions within the amygdala-mPFC circuits and their relevance to emotional processing remain unclear. To investigate this circuit, we obtained resting-state functional magnetic resonance imaging (rs-fMRI) and proton MR spectroscopy in 21 healthy subjects to assess the potential relationship between GABA levels within mPFC and the amygdala-mPFC functional connectivity. Trait anxiety was assessed using the State-Trait Anxiety Inventory (STAI-Y2). Partial correlations were used to measure the relationships among the functional connectivity outcomes, mPFC GABA levels and STAI-Y2 scores. Age, educational level and amount of the gray and white matters within 1H-MRS volume of interest were included as nuisance variables. The rs-fMRI signals of the amygdala and the vmPFC were significantly anti-correlated. This negative functional coupling between the two regions was inversely correlated with the GABA+/tCr level within the mPFC and the STAI-Y2 scores. We suggest a close relationship between mPFC GABA levels and functional interactions within the amygdala-vmPFC circuit, providing new insights in the physiology of emotion.

Keywords: Amygdala; Medial prefrontal cortex (mPFC); Trait anxiety; γ-Aminobutyric acid (GABA).

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Amygdala / diagnostic imaging
  • Amygdala / metabolism*
  • Brain Mapping
  • Creatine / metabolism
  • Emotions / physiology*
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging
  • Magnetic Resonance Spectroscopy
  • Male
  • Middle Aged
  • Neural Pathways / diagnostic imaging
  • Neural Pathways / physiology*
  • Neuropsychological Tests
  • Oxygen / blood
  • Prefrontal Cortex / diagnostic imaging
  • Prefrontal Cortex / metabolism*
  • Protons
  • Psychiatric Status Rating Scales
  • Rest
  • gamma-Aminobutyric Acid / metabolism*


  • Protons
  • gamma-Aminobutyric Acid
  • Creatine
  • Oxygen