Excellent summary of some of the recent scientific research on the main constituent of psychedelic fungi via The Nexian:
Psilocybin is a naturally occurring psychedelic compound found in many species of mushrooms. In this form it has a long history of use by humanity in the context of healing and divination, and it is still employed in this manner today by indigenous groups such as the Mazatec. Since the 1960’s awareness of psilocybin and the fungi within which it resides has spread into the Western world. Following the legal clamp down that resulted from widespread use of this and other psychedelics like LSD and mescaline at this time, scientific research into this compound and other psychedelics all but drew to a halt. In the last few years regulatory red tape has been loosening to some degree, and scientists have began studying psilocybin for a number of reasons. It appears that psilocybin is a highly multifaceted compound and has the capacity to act as a profound tool in the study of the brain and consciousness, as well as act as a treatment for a variety of psychological conditions.
Psilocybin is a compound of very low physical toxicity, but it can exert very powerful psychological effects, and the correct set and setting are of key importance when the drug is administered to reduce the chances of adverse reactions and to maximize potential benefits. On ingestion, psilocybin is dephosphorylated into the pharmacologically active molecule psilocin which closely resembles a key neurotransmitter serotonin in structure, and because of this it has a high affinity for 5-HT2A and 5-HT1serotonin receptors where it mimics the effect of this neurotransmitter. The psychedelic effects of psilocybin can be prevented by the chemical ketanserin, which acts as a 5-HT2A receptor antagonist, blocking psilocybin’s access to the receptor sites and preventing it from exerting an effect (Vollenweider et al. 1999). These receptors are located at varying densities in many parts of the brain, and play important roles in mood and motivation regulation, among other things. At medium doses psilocybin has also been found to increase an increase in cerebral metabolic rate of glucose, particularly in the frontomedial and frontolateral cortex (24.3%), anterior cingulate (24.9%) and temporomedial cortex (25.3%) brain regions (Vollenweider et al. 1997).
Recent technological developments such as functional magnetic resonance imaging (fMRI) are allowing researchers to examine the brain less invasively and with greater precision than ever before. Brain imaging studies of healthy volunteers under psilocybin have found that brain activity was reduced in the default-mode network via a reduction in blood flow, and hub regions such as the thalamus and anterior and posterior cingulate cortex were affected. This in turn has downstream effects on consciousness, leading to a more unconstrained, expansive and free flowing state when compared to cognition in a sober state (Carhart-Harris et al. 2012). An overactive default mode network is associated with depressive states and obsessive rumination, so a reduction in activity of this network may have important implications for the treatment of depression. A reduction of activity in the default-mode network is also linked to experiences of ego dissolution commonly associated with psilocybin. This network is linked to our personality and sense of self, with the latter being experienced as less solid under psilocybin, and there is a sense of novelty, with people commonly describing experiencing the world akin to new, as through child like eyes. Activity in the medial prefrontal cortex was consistently decreased by psilocybin, which is of interest as this area has been observed to be hyperactive in people experiencing major depressive episodes. Mindfulness meditation has also been found to reduce activity in these same brain regions.
Latest posts by Yugen (see all)
- Mystery School in Hyperspace: A Cultural History of DMT - Nov 9, 2015
- DMT – A Tool to Extend Survival in Clinical Death? - Jul 4, 2015
- Vines and Minds — The DMT-Nexus at Aya2014 - Apr 27, 2015