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Ana Maqueda

Johns Hopkins University

3 papers in the library · 281 citations · publishing 2015-2016

Papers

Inhibition of alpha oscillations through serotonin-2A receptor activation underlies the visual effects of ayahuasca in humans

European Neuropsychopharmacology March 26, 2016 Marta Valle, Ana Maqueda, Mireia Rabella et al. 175 citations

Ayahuasca, a psychoactive Amazonian tea, contains DMT and other compounds. In a double-blind, placebo-controlled study with 12 experienced users, ayahuasca reduced brain oscillations in delta, theta, and alpha frequency bands. The intensity of visual imagery correlated inversely with alpha-band current density in parietal and occipital cortex. Pretreatment with the 5-HT2A antagonist ketanserin blocked these neurophysiological changes, weakened the correlation between alpha activity and visual effects, and reduced subjective intensity. These results indicate that activation of the 5-HT2A receptor is central to ayahuasca's neurophysiological and visual effects in humans, despite the tea's chemical complexity.

DOI: 10.1016/j.euroneuro.2016.03.012 Ayahuasca Serotonin Ketanserin Hallucinogen +6

Salvinorin-A Induces Intense Dissociative Effects, Blocking External Sensory Perception and Modulating Interoception and Sense of Body Ownership in Humans

The International Journal of Neuropsychopharmacology June 5, 2015 Marta Valle, Montserrat Puntes, Jimena Coimbra et al. 75 citations

Salvinorin-A produces intense psychotropic effects that depend on dose: it gates external audio-visual information in a dose-dependent manner and has an inverted-U dose-response effect on body awareness. These results indicate that the kappa opioid receptor plays a prominent role in regulating sensory perception, interoception, and the sense of body ownership in humans.

DOI: 10.1093/ijnp/pyv065 Full text Interoception Hallucinogen Κ-opioid receptor Psychology +5

Naltrexone but Not Ketanserin Antagonizes the Subjective, Cardiovascular, and Neuroendocrine Effects of Salvinorin-A in Humans

The International Journal of Neuropsychopharmacology February 12, 2016 Marta Valle, Montserrat Puntes, Jimena Coimbra et al. 31 citations

The subjective and physiological effects of salvinorin-A in humans are caused by activation of kappa opioid receptors, not by serotonin-2A receptors. This finding clarifies the specific receptor mechanism responsible for the drug's effects.

DOI: 10.1093/ijnp/pyw016 Full text Serotonin Ketanserin Naltrexone Hallucinogen +7