Serotonin and the hallucinogenic metabolites of tryptamines, dimethylated tryptamines, activate the serotonin 2A receptor (5‐HT2AR), which is implicated in numerous mental health disorders. We have previously demonstrated that the 5‐HT2AR is differentially regulated by βarrestin2 (βarr2) depending upon the agonist; here we utilized βarr2 knockout mice to compare signaling profiles in vivo, by...
Although many drugs act by indirectly stimulating multiple receptors (e.g., reuptake inhibitors), relatively little is known about interactions between agonism at different receptors. This study compared the effect of serotonin (5-HT)(1A) receptor agonists with the discriminative stimulus effects of the 5-HT(2A) receptor agonist 1-(2,5-dimethoxy-4-methylphenyl)-2-aminopropane (DOM) in rats and...
Binocular rivalry refers to the fluctuations in visual awareness/suppression that occur when different images are simultaneously presented to each eye. To explore the role of serotonin (5-HT) in binocular rivalry, this study investigated the affects of the hallucinogenic 5-HT1A&2A receptor agonist psilocybin (the active compound in “magic mushrooms”), alone and after pretreatment with the...
Increasing evidence suggests a link between attention, working memory, serotonin (5-HT) and prefrontal cortex activity. In an attempt to tease out the relationship between these elements, this study tested the effects of the hallucinogenic 5-HT1A/2A receptor agonist psilocybin alone and after pretreatment with the 5-HT2A antagonist ketanserin on multiple object tracking and spatial working...
RationaleHallucinogenic serotonin 2A (5-HT2A) receptor partial agonists, such as (±)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (DOI), induce a frontal cortex-dependent head-twitch response (HTR) in rodents, a behavioral proxy of a hallucinogenic response that is blocked by 5-HT2A receptor antagonists. In addition to 5-HT2A receptors, DOI and most other serotonin-like...
Serotonin receptors of the 5-HT(2A) subtype are robustly expressed in the cerebral cortex where they have been implicated in the pathophysiology and therapeutics of mental disorders and the actions of hallucinogens. Much less is known, however, about the specific cell types expressing 5-HT(2A) receptors in cortex. In the current study we use immunohistochemical and electrophysiological...
Peduncular hallucinosis (PH) consists of formed and coloured visual images, which the patient knows are unreal; it is often associated with lesions of the pons, midbrain and diencephalon. A 72-year-old man had noted the sudden onset of visual hallucinations one year before, specifying the time and body position in a 4-week, 24-h diary. Thereafter, he underwent video-polysomnography (VPSG),...
Serotonin, a biogenic amine, is present in significant amounts in many structures of the CNS. It is involved in regulation of a wide variety of physiological functions, such as sensory and motor functions, memory, mood, and secretion of hormones including reproductive hormones. It has also been implicated in the etiology of a range of psychiatric disorders such as anxiety, depression, and...
J. Neurochem. (2009) 112 , 951–962. Abstract 3,4‐Methylenedioxymethamphetamine (MDMA; ‘Ecstasy’) is a popular recreational drug used worldwide. This study aimed to determine the effects of this compound on the expression of nerve terminal serotonergic markers in rats. Experiment 1 investigated MDMA‐induced changes in levels of the serotonin transporter (SERT) and the vesicular monoamine...
RATIONALE: Compounds that activate the 5-HT(2A) receptor, such as lysergic acid diethylamide (LSD), act as hallucinogens in humans. One notable exception is the LSD congener lisuride, which does not have hallucinogenic effects in humans even though it is a potent 5-HT(2A) agonist. LSD and other hallucinogens have been shown to disrupt prepulse inhibition (PPI), an operational measure of...