Posterior cingulate cortex
202308161352
Summary
A mysterious region of the brain: large size, buffered location, and rich vasculature means it’s well protected from damage. Couple that with ~20% higher metabolic activity than the rest of the brain, and its association with the default mode network, and you’ve got yourself a quite interesting region to explore.
Thought to be associated with arousal and awareness, as well as the control of balance b/w internally & externally directed thought (Leech2014)
Failure to suppress PCC activity is associated with intrusion of internal mentation
Core region of the DMN that receives information from other core regions, including the mPFC and bilateral angular gyrus.
Metabolism in the PCC is ~20% higher than most other brain regions Buckner2008
- psilocybin decreases its CBF by up to 20% in some subjects Carhart-Harris2012.
CBF and metabolic rate approx. 40% higher in PCC than average of rest of brain Raichle2001.
Possible function of the PCC oscillations is to constrain activity of limbic circuits like the medial temporal lobes, which reciprocally drive input to PCC.
- Fornix stimulation associated with significantly increased glucose metabolism in the PCC (Laxton2012, src:Carhart-Harris2014)
Decreased functional connectivity in the PCC after LSD and psilocybin administration (Psychedelics decrease BOLD activity)
Increased functional connectivity between PCC and ACC 24h after ayahuasca (Sampedro2017)
- Concomitant reductions in glutamate, glutamine, creatine, N-acetylaspartate + N-acetylaspartylglutamate in PCC