Dietmar Schmitz

Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany; German Center for Neurodegenerative Diseases (DZNE) Berlin, 10117 Berlin, Germany; Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Einstein Center for Neuroscience, 10117 Berlin, Germany; Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, NeuroCure Cluster of Excellence, 10117 Berlin, Germany; Humboldt-Universität zu Berlin, Bernstein Center for Computational Neuroscience, Philippstr. 13, 10115 Berlin, Germany.

2 papers in the library · 14 citations · publishing 2020-2024

Papers

Synthetic surprise as the foundation of the psychedelic experience

Neuroscience & Biobehavioral Reviews January 15, 2024 Dietmar Schmitz, Roberto de Filippo 13 citations

Psychedelic agents like LSD and psilocybin alter consciousness by activating the 5-HT2A receptor. The authors hypothesize that these drugs enforce a state of synthetic surprise through biased activation of the 5-HT receptor system, drawing on recent insights into serotonin's role in signaling surprise. Within the predictive coding framework, surprise corresponds to prediction error—the mismatch between predictions and sensory input. The precision of prediction error determines its effect on priors, allowing dynamic interaction between top-down expectations and incoming data. Integrating findings on predictive coding circuitry and 5-HT2A receptor transcriptomic data, the authors propose a biological implementation emphasizing inhibitory interneurons. This has implications for clinical use, where psychedelics may disrupt maladaptive patterns by inducing surprise.

DOI: 10.1016/j.neubiorev.2024.105538 Psilocybin Predictive coding Neuroscience Surprise +6

Somatostatin interneurons activated by 5-HT2A receptor suppress slow oscillations in medial entorhinal cortex

bioRxiv Preprint Server May 26, 2020 Roberto De Filippo, Benjamin R. Rost, Alexander Stumpf et al. 1 citation preprint

Serotonin (5-HT) is a key neuromodulator in the mammalian brain, but how it affects synchronized cortical network activity is not fully understood. This work shows that MDMA and fenfluramine, two drugs that release 5-HT, inhibit slow oscillations—a default cortical activity pattern—in the entorhinal cortex of anesthetized mice. The suppression occurs through activation of somatostatin-expressing interneurons via the 5-HT2A receptor. Because 5-HT2A receptor signaling is implicated in psychiatric disorders and mediates effects of serotonergic drugs, this link between these interneurons and serotonin may help clarify these complex topics.

DOI: 10.1101/2020.05.26.113373 Full text