Brain communications
January 1, 2024
Jakub Vohryzek, Joana Cabral, Louis-David Lord et al.
33 citations
Psilocybin therapy for depression shows promise, but its causal mechanisms are unknown. By comparing brain dynamics in treatment responders (those with >50% symptom reduction) and non-responders before treatment, researchers used large-scale brain modeling to identify brain regions whose perturbation could shift a depressive brain state to a healthy one. The identified regions correlated with density maps of serotonin receptors 5-HT2a and 5-HT1a, where psilocin (psilocybin's active metabolite) acts as an agonist. These findings provide causal mechanistic evidence linking specific brain regions and serotonergic transmission to recovery from depression via psilocybin.
Brain communications
January 1, 2024
Ashley Ghaw, Alisha Chunduri, Arnold Chang et al.
13 citations
Lysergic acid diethylamide (LSD) produced a dose-dependent increase in negative blood oxygen level-dependent (BOLD) signal, indicating decreased brain activity, in awake rats. The most affected regions were the primary olfactory system, prefrontal cortex, thalamus, and hippocampus. Contrary to the hypothesis that LSD would increase activity in the prefrontal cortex and thalamus while decreasing hippocampal activity, the results showed an acute decrease in activity across these areas. However, functional connectivity increased between the thalamus and somatosensory cortex, and between the cerebellar nuclei and surrounding brainstem areas. The enhanced thalamus-sensorimotor connectivity aligns with human studies, while the unexpected increase in cerebellar nuclei connectivity raises questions about its role in hallucinogenic effects.
Brain communications
January 1, 2025
Eugénie Cataldo, Eda Tipura, Corrado Corradi-Dell'Acqua et al.
4 citations
About 30% of stroke patients show a subtle form of body part disownership—a feeling that a hand, arm, leg, or part of the face does not belong to them—that standard verbal interviews miss. Using brain lesion analyses and network-based modeling in 105 hospitalized stroke patients and 55 healthy controls, the study found that this covert disownership involves widespread disconnections between temporo-occipital and parietal networks, as well as fronto-basal and occipital pathways, rather than damage to a single brain region. Key structures implicated include the right insula and basal ganglia for upper limb ownership, and the left superior longitudinal fasciculus for right hand disownership. The findings suggest that sensitive, non-verbal assessments are needed to detect this disorder early after stroke, and that understanding brain damage as network disruption can improve rehabilitation.
Brain communications
January 1, 2026
Raina Vin, Jordan Galbraith, Rashina Seabury et al.
Hallucinations may arise from an over-reliance on prior knowledge during perception, potentially as a compensatory response to degraded sensory information. This perspective unifies visual hallucinations across Charles Bonnet syndrome, dementia with Lewy bodies, and psychosis within a Bayesian computational framework. In each disorder, sensory signal disruptions at different levels of the visual processing hierarchy produce hallucinations with distinct characteristics, reflecting the localization and overtness of the disruption. Discrete sensory disruptions in Charles Bonnet syndrome translate to hallucinations via known circuits, while different disruptions in dementia with Lewy bodies and schizophrenia lead to distinct phenomenology, comorbidities, and circuit involvement. This framework may help identify pathophysiologically distinct patient subgroups and guide new interventions.
Brain communications
January 1, 2025
Christos Ganos, Michael A Ferguson, Kurt Gray et al.
Religious traditions worldwide include specific actions, termed religious motor behaviours, that can be classified using concepts from movement neuroscience and neurology. These behaviours range from decreased motor output, such as ritualistic silence, to increased output like ritual dances. They also vary in the experience of volition: some involve a heightened sense of personal control, while others feel controlled by an external divine source. Examples include repetitive rituals, automatisms with altered volition, and possession-like states. The authors show parallels between these religious behaviours and motor phenomena in neurological disorders, particularly functional neurological symptoms, without pathologizing them. The work highlights how movement neuroscience and religious activity can inform each other.