Hallucinogens, including mescaline, psilocybin, and lysergic acid diethylamide (LSD), profoundly affect perception, cognition, and mood. All known drugs of this class are 5-HT(2A) receptor (2AR) agonists, yet closely related 2AR agonists such as lisuride lack comparable psychoactive properties. Why only certain 2AR agonists are hallucinogens and which neural circuits mediate their effects are poorly understood. By genetically expressing 2AR only in cortex, we show that 2AR-regulated pathways on cortical neurons are sufficient to mediate the signaling pattern and behavioral response to hallucinogens. Hallucinogenic and nonhallucinogenic 2AR agonists both regulate signaling in the same 2AR-expressing cortical neurons. However, the signaling and behavioral responses to the hallucinogens are distinct. While lisuride and LSD both act at 2AR expressed by cortex neurons to regulate phospholipase C, LSD responses also involve pertussis toxin-sensitive heterotrimeric G(i/o) proteins and Src. These studies identify the long-elusive neural and signaling mechanisms responsible for the unique effects of hallucinogens.
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http://dx.doi.org/10.1016/j.neuron.2007.01.008 | DOI Listing |
J Neuroinflammation
March 2023
Department of Molecular and Integrative Physiology, University of Michigan Medical School, 7301 MSRB III, 1150 W. Medical Center Dr., Ann Arbor, MI, 48109-0644, USA.
Background: Noradrenergic neurons in the locus coeruleus (LC) are the primary source of norepinephrine (NE) in the brain and degeneration of these neurons is reported in the early stages of Parkinson's disease (PD), even prior to dopaminergic neuron degeneration in the substantia nigra (SN), which is a hallmark of PD pathology. NE depletion is generally associated with increased PD pathology in neurotoxin-based PD models. The effect of NE depletion in other models of PD-like α-synuclein-based models is largely unexplored.
View Article and Find Full Text PDFNeuroimage
October 2022
Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Center for Psychedelic and Consciousness Research, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA; Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA. Electronic address:
Background: Classic psychedelics, such as psilocybin and LSD, and other serotonin 2A receptor (5-HT) agonists evoke acute alterations in perception and cognition. Altered thalamocortical connectivity has been hypothesized to underlie these effects, which is supported by some functional MRI (fMRI) studies. These studies have treated the thalamus as a unitary structure, despite known differential 5-HT expression and functional specificity of different intrathalamic nuclei.
View Article and Find Full Text PDFPharmaceuticals (Basel)
April 2022
Department of Clinical and Experimental Medicine, University of Messina, Via C. Valeria, 98125 Messina, Italy.
Fuchs endothelial corneal dystrophy (FECD) is a bilateral, hereditary syndrome characterized by progressive irreversible injury in the corneal endothelium; it is the most frequent cause for corneal transplantation worldwide. Oxidative stress induces the apoptosis of corneal endothelial cells (CECs), and has a crucial function in FECD pathogenesis. The stimulation of the adenosine A receptor (A) inhibits oxidative stress, reduces inflammation and modulates apoptosis.
View Article and Find Full Text PDFMol Pharmacol
February 2022
Department of Biochemistry and Molecular Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, (M.I., F.D.P., J.L.B.); and Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan (A.I.)
G protein-coupled receptors (GPCRs) transduce a diverse variety of extracellular stimuli into intracellular signaling. These receptors are the most clinically productive drug targets at present. Despite decades of research on the signaling consequences of molecule-receptor interactions, conformational components of receptor-effector interactions remain incompletely described.
View Article and Find Full Text PDFPostep Psychiatr Neurol
December 2021
Department of Neurochemistry, Institute of Psychiatry and Neurology, Warsaw, Poland.
Purpose: This article discusses the modulatory effects of the serotonergic system on the behavioral and neurochemical effects exerted by psychostimulants, mainly cocaine.
Views: The mesocorticolimbic dopaminergic system plays an important role in the rewarding effects of psychostimulants and the long-lasting neuroadaptive changes underlying the development of addiction. Dopaminergic brain regions such as the ventral tegmental area (VTA) and substantia nigra (SN) and their projection fields (prefrontal cortex - PFC, nucleus accumbens - Acb, dorsal striatum) are innervated by serotonergic neurons that can modulate this system.
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