Psychedelics decrease BOLD activity
- Decrease in brain activity after intravenous administration of psilocybin Carhart-Harris2012
- PCC, retrosplenial cortex, precuneus, bilateral angular gyrus, supramarginal gyrus, rostral and dorsal ACC, paracingulate gyrus, mPFC, frontoinsular cortex, lateral OFC, frontal operculum, precentral gyrus, superior frontal gyrus, middle frontal gyrus, inferior frontal gyrus.
- Group-level results from Carhart-Harris2012 show significant CBF decreases in bilateral thalamus, putamen, and hypothalamus.
- Decrease in neural activity of the hypothalamus may explain anecdotal reports that Psychedelics treat symptoms of cluster headaches Sewell2006.
May be explained (at least in part):
- by the fact that 5-HT2a receptors increase GABAergic transmission.
- by 5-HT2a-mediated excitation of fast-spiking interneurons terminating on Pyramidal neurons or excitation of Pyramidal neurons projecting onto interneurons Alexander2009 (src: Carhart-Harris2012).
Related Notes
Psychedelics suppress the default mode network
Paradoxical relationship with psychedelics between glucose metabolism and blood flow