Increased Global Functional Connectivity Correlates with LSD-Induced Ego Dissolution

@article{Tagliazucchi2016IncreasedGF,
  title={Increased Global Functional Connectivity Correlates with LSD-Induced Ego Dissolution},
  author={Enzo Tagliazucchi and Leor Roseman and Mendel Kaelen and Csaba Orban and Suresh D. Muthukumaraswamy and Kevin Murphy and Helmut Laufs and Robert Leech and John McGonigle and Nicolas A. Crossley and Edward T. Bullmore and Tim M. Williams and Mark Bolstridge and Amanda Feilding and David J. Nutt and Robin Lester Carhart-Harris},
  journal={Current Biology},
  year={2016},
  volume={26},
  pages={1043-1050}
}
Lysergic acid diethylamide (LSD) is a non-selective serotonin-receptor agonist that was first synthesized in 1938 and identified as (potently) psychoactive in 1943. Psychedelics have been used by indigenous cultures for millennia [1]; however, because of LSD's unique potency and the timing of its discovery (coinciding with a period of major discovery in psychopharmacology), it is generally regarded as the quintessential contemporary psychedelic [2]. LSD has profound modulatory effects on… 
Acute effects of lysergic acid diethylamide (LSD) on resting brain function.
TLDR
Overall, previous results across studies indicate that LSD administration is associated with extensive alterations in functional brain connectivity, measuring the correlated activities between different brain regions, and models proposing that hallucinogenic drugs exert their effects by inhibiting cerebral filtering of external and internal data are in agreement.
Changes in global brain connectivity in LSD-induced altered states of consciousness are attributable to the 5-HT2A receptor
TLDR
It is shown that whole-brain data-driven spatial patterns of LSD effects matched 5-HT2A receptor cortical gene expression in humans, which along with ketanserin effects, strongly implicates the 5- HT2A receptors in LSD’s neuropharmacology.
LSD flattens the functional hierarchy of the human brain
LSD is a potent serotonergic psychedelic compound. Findings indicate that psychotherapeutic applications of LSD and related psychedelic compounds have value in the treatment of mental health
Effective connectivity changes in LSD-induced altered states of consciousness in humans
TLDR
Investigation of directed connectivity between cortico–striato–thalamo-cortical (CSTC) regions after administration of LSD provides evidence that LSD alters directed connectivity within CSTC pathways in humans, suggesting that a disintegration of information processing within these loops is underlying the psychedelic state.
Advances and challenges in neuroimaging studies on the effects of serotonergic hallucinogens: Contributions of the resting brain.
TLDR
Although these studies are limited by small sample sizes and might be biased by unspecific drug effects on physiological parameters and the vascular system, current results indicate that neuroimaging could be a useful tool to elucidate the neuronal correlates of hallucinogenic effects.
Changes in global and thalamic brain connectivity in LSD-induced altered states of consciousness are attributable to the 5-HT2A receptor
TLDR
The critical role of 5-HT2A in LSD’s mechanism, which informs its neurobiology and guides rational development of psychedelic-based therapeutics is pinched, which strongly implicate the 5- HT2A receptor in LSD's neuropharmacology.
Increased sensitivity to strong perturbations in a whole-brain model of LSD
TLDR
A novel perturbational approach based on a whole-brain computational model is applied, which opens up the possibility to externally perturb different brain regions in silico and investigate differences in dynamical stability of different brain states, i.e. the dynamical response of a certain brain region to an external perturbation.
Decreased Directed Functional Connectivity in the Psychedelic State
TLDR
Changes in functional connectivity following the controlled administration of LSD, psilocybin and low-dose ketamine as well as, for comparison, the (non-psychedelic) anticonvulsant drug tiagabine are described.
Me, myself, bye: regional alterations in glutamate and the experience of ego dissolution with psilocybin
TLDR
It is demonstrated that psilocybin induced region-dependent alterations in glutamate, which predicted distortions in the subjective experience of one’s self (ego dissolution), which may provide a neurochemical basis for therapeutic effects as witnessed in ongoing clinical trials.
Decreased directed functional connectivity in the psychedelic state
TLDR
Changes in functional connectivity following the controlled administration of LSD, psilocybin and low-dose ketamine as well as, for comparison, the (non-psychedelic) anticonvulsant drug tiagabine are described.
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