Recent advances in the neuropsychopharmacology of serotonergic hallucinogens

“…that psilocybin reduces activity and connectivity in core nodes of the default-mode network, brain regions that are active during the resting state and potentially involved in introspective processes (for more information, see: Raichle et al., 2001; Mason et al., 2007; Buckner et al., 2008).”

“…that psilocybin reduces activity and connectivity in core nodes of the default-mode network, brain regions that are active during the resting state and potentially involved in introspective processes (for more information, see: Raichle et al., 2001; Mason et al., 2007; Buckner et al., 2008).”

“CSTC loops are parallel, anatomically segregated circuits relaying information between the basal ganglia, thalamus, and cortex (Alexander et al., 1986, 1990).”

“Since cortical oscillations play a fundamental role in a diverse set of mental processes and are required for the coordination of neural processing (Gray et al., 1989; Singer, 1999; Buzsaki and Draguhn, 2004; Sejnowski and Paulsen, 2006; Fries, 2009; Klimesch, 2012), it is tempting to speculate that the reduction of n…”

“One potential explanation is that the hemodynamic responses measured by fMRI are actually better correlated with cortical oscillatory activity than with neuronal firing (Mathiesen et al., 1998; Logothetis et al., 2001; Behav Brain Res.”

“Since cortical oscillations play a fundamental role in a diverse set of mental processes and are required for the coordination of neural processing (Gray et al., 1989; Singer, 1999; Buzsaki and Draguhn, 2004; Sejnowski and Paulsen, 2006; Fries, 2009; Klimesch, 2012), it is tempting to speculate that the reduction of n…”

“Under anesthesia or during slow-wave sleep, cortical networks display slow (0.5–1 Hz) and delta (1–4 Hz) oscillations (Steriade et al., 1993a,b; Steriade, 1997) that reflect alternations between periods of silence (DOWN states) and periods of depolarization with repetitive spiking (UP states).”

“Since cortical oscillations play a fundamental role in a diverse set of mental processes and are required for the coordination of neural processing (Gray et al., 1989; Singer, 1999; Buzsaki and Draguhn, 2004; Sejnowski and Paulsen, 2006; Fries, 2009; Klimesch, 2012), it is tempting to speculate that the reduction of n…”

“The 5-HT2 receptor class was later reorganized to include three subtypes: 5-HT2A (equivalent to the site known historically as the 5-HT2 receptor or the D receptor), 5-HT2B (formerly known as the 5HT2F receptor), and 5-HT2C (formerly known as the 5-HT1C receptor) (Hoyer et al., 1994).”

“The classic hallucinogens, which include psilocybin (psilocin) and (+)-lysergic acid diethylamide (LSD), are a structurally diverse group of compounds that are 5-HT2A receptor agonists and produce a unique profile of changes in thoughts, perceptions, and emotions (Halberstadt, 2015; Nichols, 2016).”

“In the study byHalberstadt et al. (2011a), the response to psilocin was not affected by deletion of the 5-HT2A receptor gene.”

“LSD has a high affinity for a range of different neurotransmitter receptors, but its characteristic psychological effects are thought to be mediated by serotonin 2A receptor (5-HT2AR) agonism (7).”

“…this limitation, we also wish to emphasise that the evidence is compelling that 5-HT2AR agonism is key to psychedelics’ most characteristic effects (Halberstadt, 2015), 5-HT1AR agonism attenuates rather than augments these effects (Pokorny et al., 2016; Strassman, 1996) and more selective 5-HT2AR…”