Forty days of mindfulness meditation training in 13 novice meditators altered functional connectivity in brain networks linked to self-referential thought and emotion regulation. During meditation, internal consistency increased in the precuneus and temporoparietal junction but decreased in frontal regions, and connectivity between the dorsal anterior cingulate cortex and anterior insula was reduced. After training, resting-state connectivity between the pregenual anterior cingulate and dorsomedial prefrontal cortex decreased. Participants also reported significantly reduced depression and anxiety scores. These results suggest that meditation may produce antidepressant effects through neuroplastic changes in brain networks underlying affective disorders.
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.