Glutamate concentration in the dorsal anterior cingulate cortex (dACC) modulates brain response during salience processing. In 27 healthy subjects, higher glutamate levels in the dACC balanced the attenuation of deactivation in the posterior cingulate cortex (PCC) caused by stimulus salience, such as sexual content or unexpected emotional content. This suggests that glutamate in the dACC plays a regulatory role in how the brain processes salient stimuli.
Forty days of mindfulness meditation training in novices produced overlapping structural and functional changes in the precuneus, a posterior region of the default mode network. Cortical thickness increased while low-frequency brain activity (ALFF) decreased in that area. Reduced activity in the left precuneus and posterior cingulate cortex correlated with lower depression scores on the CES-D scale. The findings suggest that regional overlap of structural and functional plasticity may reflect different components of the complex neural changes induced by mindfulness meditation training.