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Ole Jensen

Universitätsmedizin Göttingen

4 papers in the library · 35 citations · publishing 2021-2026

Papers

Cellular Uptake of Psychostimulants – Are High- and Low-Affinity Organic Cation Transporters Drug Traffickers?

Frontiers in Pharmacology January 20, 2021 Ole Jensen, Muhammad Rafehi, Lukas Gebauer et al. 24 citations

Several psychostimulants and hallucinogens are transported by organic cation transporters (OCTs), which may contribute to individual differences in their metabolism and toxicity. Mescaline is strongly transported by OCT1, with transport varying substantially across common genetic variants: reduced in variants *2, *3, *4, *5, *6, and moderately increased in *8. Other substances—methamphetamine, para-methoxymethamphetamine, (-)-ephedrine, cathine, and dimethyltryptamine—are substrates of OCT2, with affinities and transport capacities reduced by up to half in the A270S variant. Cathine also acts as a substrate for NET and DAT. These findings suggest that genetic variation in OCTs could underlie highly variable adverse reactions to mescaline and other psychostimulants.

How do psychostimulants enter the human brain? Analysis of the role of the proton-organic cation antiporter.

Biochemical pharmacology October 1, 2021 Alexandra Sachkova, David Alexander Doetsch, Ole Jensen et al. 11 citations

Many psychostimulants and hallucinogens are hydrophilic and positively charged, making it unclear how they cross the blood-brain barrier (BBB). A genetically uncharacterized proton-organic cation (H+/OC) antiporter at the BBB may mediate this transport. Using hCMEC/D3 cells, uptake of methylenedioxyamphetamines, amphetamines, and dimethyltryptamine (DMT) was strongly inhibited by imipramine and diphenhydramine, while cathine was weakly inhibited and mescaline not significantly. Exchange transport after preloading with diphenhydramine left only 1.9% to 7.8% of several compounds in cells, but mescaline showed no exchange. Except for mescaline, all tested psychostimulants were substrates of the H+/OC antiporter, highlighting the need to better characterize this transporter.

Hierarchical brain dynamics supporting visual perceptual transitions

Science Advances May 8, 2026 Max Levinson, Alice Waitt, Katharina Duecker et al.

Transitions in conscious visual perception involve two distinct neural mechanisms: boundary fading in visual cortex, marked by increased excitability and reduced alpha-band activity indicating a shift in excitation-inhibition balance, and higher-order perceptual monitoring in motor cortex, reflected by decreased high-alpha and beta-band activity. Microsaccadic eye movements, which delay the illusion, selectively reset both processes. These findings support a hierarchical framework where visual and motor systems jointly shape changes in conscious experience.

An adversarial collaboration to critically evaluate theories of consciousness

bioRxiv Preprint Server June 23, 2023 Oscar Ferrante, Urszula Gorska-Klimowska, Simon Henin et al. preprint

An open science adversarial collaboration directly juxtaposed Integrated Information Theory (IIT) and Global Neuronal Workspace Theory (GNWT) by investigating neural correlates of visual experience. 256 human subjects viewed suprathreshold stimuli for variable durations while neural activity was measured with fMRI, MEG, and ECoG. Information about conscious content was found in visual, ventro-temporal, and inferior frontal cortex, with sustained responses in occipital and lateral temporal cortex reflecting stimulus duration, and content-specific synchronization between frontal and early visual areas.