Biology subjects

Theunissen, E.

Publications and source records attributed to Theunissen, E..

4 recordsLinked to original sources

bioRxiv2026

Tuning in together: LSD enhances inter-brain synchrony and felt connectedness in romantic couples

Social connection is fundamental to human wellbeing. Serotonergic psychedelics such as lysergic acid diethylamide (LSD) acutely heighten subjective connectedness, yet their effects on real-time social connection remain poorly understood. Using EEG hyperscanning in a randomized, double-blind, placebo-controlled crossover study, we recorded neural activity simultaneously from both members of healthy romantic couples (N=25) who received LSD (50 g) or placebo together, across resting and interactive states. LSD increased subjective connectedness, including feelings of love, closeness, trust, and being "in sync," while reducing loneliness, compared to placebo. This affiliative shift dissociated from the drugs pharmacokinetic time-course, remaining elevated as subjective intensity and plasma concentration declined. In parallel, LSD increased inter-brain synchrony during shared rest, carried specifically by theta-band amplitude-envelope coupling. Importantly, this effect survived two complementary controls. First, it exceeded coupling between unrelated individuals and second the effects depended on contemporaneous neural alignment rather than shared drug-induced dynamics. Exploratory analyses showed that romantic partners with greater resting synchrony reported greater feelings of connectedness. These findings provide the first evidence that a psychedelic enhances brain-to-brain coupling between people, linking a pharmacologically induced state of felt connection to a measurable signature shared across interacting brains.

neuroscience↗

bioRxiv2025

ADAR RNA editing for cardiovascular disease: Targeting B4GALT1 to modulate lipid metabolism through reduced galactosyltransferase activity

Cardiovascular disease remains a leading cause of mortality despite current therapies targeting low-density lipoprotein cholesterol (LDL-C). Beta-1,4-galactosyltransferase 1 (B4GALT1), a central glycosyltransferase enzyme that regulates lipoprotein metabolism and hemostasis, is a promising therapeutic target. To evaluate its therapeutic potential as a protective variant, B4galt1 p.Asn352Ser was introduced into the ribonucleic acid (RNA) of healthy wild-type and APOE*3-Leiden.CETP transgenic mice, a well-established model for hyperlipidemia with a humanized lipoprotein metabolism, using editing oligonucleotides and the endogenous adenosine deaminases acting on RNA enzymes. The impact on hepatic glycosylation and systemic lipid homeostasis was investigated using multi-omics profiling. Editing of B4galt1 messenger RNA ([~]9-18%) resulted in substantial reductions in total cholesterol (-61%), apolipoprotein B (-72%), LDL-C (-30%), fibrinogen (-55%) (all p < 0.05), and triglycerides (-28%; p > 0.05), without altering B4galt1 expression. Proteomics of plasma and liver identified early suppression of lipogenesis and lipoprotein assembly, followed by sustained suppression of cholesterol biosynthesis and coagulation pathways. Glycomic analysis revealed remodeling of circulating glycoprotein architecture, consistent with altered B4GALT1 activity. Transcript-protein concordance was strongest in lipid pathways, while glycosylation and coagulation showed domain-specific regulatory patterns. These findings support targeting B4GALT1 using RNA editing to reduce cardiometabolic risk.

genetics↗

bioRxiv2023

Assessment of the acute effects of 2C-B vs psilocybin on subjective experience, mood and cognition

2,5-dimethoxy-4-bromophenethylamine (2C-B) is a hallucinogenic phenethylamine derived from mescaline. Observational and preclinical data have suggested it to be capable of producing both subjective and emotional effects on par with other classical psychedelics and entactogens. Whereas it is the most prevalently used novel serotonergic hallucinogen to date, its acute effects and distinctions from classical progenitors have yet to be characterised in a controlled study. We assessed for the first time the immediate acute subjective, cognitive, and cardiovascular effects of 2C-B (20 mg) in comparison to psilocybin (15mg) and placebo in a within-subjects, double-blind, placebo-controlled study of 22 healthy psychedelic-experienced participants. 2C-B elicited alterations of waking consciousness of a psychedelic nature, with dysphoria, subjective impairment, auditory alterations, and affective elements of ego dissolution largest under psilocybin. Participants demonstrated equivalent psychomotor slowing and spatial memory impairments under either compound compared to placebo, as indexed by the Digit Symbol Substitution Test (DSST), Tower of London (TOL) and Spatial Memory Task (SMT). Neither compound produced empathogenic effects on the Multifaceted Empathy Test (MET). 2C-B induced transient pressor effects to a similar degree as psilocybin. The duration of self-reported effects of 2C-B was shorter than that of psilocybin, largely resolving within 6 hours. Present findings support the categorisation of 2C-B as a subjectively "lighter" psychedelic. Tailored dose-effect studies are needed to discern the pharmacokinetic dependency of 2C-Bs experiential overlaps.

pharmacology and toxicology↗

bioRxiv2021

Spatial patterns in functional brain connectomes reflect acute and chronic cannabis use.

Resting state fMRI has been employed to identify alterations in functional connectivity within or between brain regions following acute and chronic exposure to {Delta}9-tetrahydrocannabinol (THC), the psychoactive component in cannabis. Most studies focused a priori on a limited number of local brain areas or circuits, without considering the impact of cannabis on wholebrain network organization. The present study attempted to identify changes in the wholebrain human functional connectome as assessed with ultra-high field (7T) resting state scans of occasional (N=12) and chronic cannabis users (N=14) during placebo and following vaporization of cannabis. Two distinct data-driven methodologies, i.e. network-based statistics (NBS) and connICA, were used to identify changes in functional connectomes associated with acute cannabis intoxication and chronic cannabis use. Both methodologies revealed a broad state of hyperconnectivity within the entire range of major brain networks in chronic cannabis users compared to occasional cannabis users, which might be reflective of an adaptive network reorganization following prolonged cannabis exposure. The connICA methodology also extracted a distinct spatial connectivity pattern of hypoconnectivity involving the dorsal attention, limbic, subcortical and cerebellum networks and of hyperconnectivity between the default mode and ventral attention network, that was associated with the feeling of subjective high during THC intoxication across both user groups. Whole-brain network approaches identified spatial patterns in functional brain connectomes that distinguished acute from chronic cannabis use, and offer an important utility for probing the interplay between short and long-term alterations in functional brain dynamics when progressing from occasional to chronic use of cannabis.

neuroscience↗