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bioRxiv

76 papers in the library · 23 citations · publishing 2018-2026

Papers

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Diminished functional gradient of the precuneus during altered states of consciousness

bioRxiv December 17, 2024 Dian Lyu, Ram Adapa, Robin Carhart-Harris et al. preprint

Abstract The relationship between the default mode network (DMN) and task-positive networks, such as the frontoparietal control network (FPCN), is a prominent feature of functional connectivity (FC) in the human brain. This relationship is primarily anticorrelated at rest in healthy brains and is disrupted in altered states of consciousness. Although the DMN and FPCN seem to perform distinct...

Classification of psychedelic drugs based on brain-wide imaging of cellular c-Fos expression

bioRxiv May 26, 2024 Farid Aboharb, Pasha A. Davoudian, Ling-Xiao Shao et al. preprint

Psilocybin, ketamine, and MDMA are psychoactive compounds that exert behavioral effects with distinguishable but also overlapping features. The growing interest in using these compounds as therapeutics necessitates preclinical assays that can accurately screen psychedelics and related analogs. We posit that a promising approach may be to measure drug action on markers of neural plasticity in...

Measuring the dynamic balance of integration and segregation underlying consciousness, anesthesia, and sleep

bioRxiv April 15, 2024 Hyunwoo Jang, George A. Mashour, Anthony G. Hudetz et al. preprint

Consciousness requires a dynamic balance of integration and segregation in functional brain networks. An optimal integration-segregation balance depends on two key aspects of functional connectivity: global efficiency (i.e., integration) and clustering (i.e., segregation). We developed a new fMRI-based measure, termed the integration-segregation difference (ISD), which captures both aspects. We...

Transient destabilization of whole brain dynamics induced by DMT

bioRxiv January 29, 2024 Juan Ignacio Piccinini, Yonatan Sanz Perl, Carla Pallavicini et al. preprint

Abstract The transition towards the brain state induced by psychedelic drugs is frequently neglected in favor of a static description of their acute effects. We used a time-dependent whole-brain model to reproduce large-scale brain dynamics measured with fMRI from 15 volunteers under 20 mg intravenous N,N-Dimethyltryptamine (DMT), a short-acting psychedelic. To capture its transient effects, we...

Statistical diversity distinguishes global states of consciousness

bioRxiv December 7, 2023 Joseph Starkey, Robin Carhart-Harris, Andrea Pigorini et al. preprint

Abstract Application of complexity measures to neurophysiological time series has seen increased use in recent years to identify neural correlates of global states of consciousness. Lempel-Ziv complexity is currently the de-facto complexity measure used in these investigations. However, by simply counting the number of patterns, this measure theoretically takes its maximum value for data that...

Harmonic decomposition of spacetime (HADES) framework characterises the spacetime hierarchy of the DMT brain state

bioRxiv August 21, 2023 Jakub Vohryzek, Joana Cabral, Christopher Timmermann et al. 7 citations preprint

Abstract The human brain is a complex system, whose activity exhibits flexible and continuous reorganisation across space and time. The decomposition of whole-brain recordings into harmonic modes has revealed a repertoire of gradient-like activity patterns associated with distinct brain functions. However, the way these activity patterns are expressed over time with their changes in various...

Cortico-thalamo-cortical interactions modulate electrically evoked EEG responses in mice

bioRxiv March 28, 2023 Leslie D. Claar, Irene Rembado, Jacqulyn R. Kuyat et al.

Perturbational complexity analysis predicts the presence of consciousness in volunteers and patients by stimulating the brain with brief pulses, recording electroencephalographic (EEG) responses, and computing their spatiotemporal complexity. We examined the underlying neural circuits in mice by directly stimulating cortex while recording with EEG and Neuropixels probes during wakefulness and...

Neural substrates of cognitive impairment in a NMDAR hypofunction mouse model of schizophrenia and rescue by risperidone

bioRxiv January 18, 2023 Cristina Delgado-Sallent, Thomas Gener, Pau Nebot et al. preprint

NMDAR hypofunction is a pathophysiological mechanism relevant for schizophrenia. Acute administration of the NMDAR antagonist phencyclidine (PCP) induces psychosis in patients and animals while subchronic PCP (sPCP) produces cognitive dysfunction for weeks. We investigated the neural correlates of memory and perceptual impairments in mice treated with sPCP and the rescuing abilities of the...

Phylogenomics of the psychoactive mushroom genusPsilocybeand evolution of the psilocybin biosynthetic gene cluster

bioRxiv December 15, 2022 Alexander J. Bradshaw, Virginia Ramírez-Cruz, Ali R. Awan et al. 5 citations preprint

Abstract Psychoactive mushrooms in the genus Psilocybe have immense cultural value and have been used for centuries in Mesoamerica. Despite a recent surge in interest in these mushrooms due to emerging evidence that psilocybin, the main psychoactive compound, is a promising therapeutic for a variety of mental illnesses, their phylogeny and taxonomy remain substantially incomplete. Moreover, the...

Network analysis of the human structural connectome including the brainstem

bioRxiv July 22, 2022 Salma Salhi, Youssef Kora, Gisu Ham et al.

The underlying anatomical structure is fundamental to the study of brain networks and is likely to play a key role in the generation of conscious experience. We conduct a computational and graph-theoretical study of the human structural connectome incorporating a variety of subcortical structures including the brainstem, which is typically not considered in similar studies. Our computational...

Behavioural and molecular characterisation of the Dlg2 haploinsufficiency rat model of genetic risk for psychiatric disorder

bioRxiv October 12, 2021 Sophie Waldron, Rachel Pass, Simonas Griesius et al.

Genetic studies implicate disruption to the DLG2 gene in copy number variants as increasing risk for schizophrenia, autism spectrum disorders and intellectual disability. To investigate psychiatric endophenotypes associated with DLG2 haploinsufficiency (and concomitant PSD-93 protein reduction) a novel clinically relevant Dlg2+/- rat was assessed for abnormalities in anxiety, sensorimotor...

Physiological basis underlying antidepressant-induced activation of TrkB receptors

bioRxiv August 31, 2021 Okko Alitalo, Samuel Kohtala, Marko Rosenholm et al. preprint

We show that both pharmacological and non-pharmacological treatments of depression activate TrkB receptors—a well-established target of antidepressants—by inducing a physiological response coupled to sedation. Several rapid-acting antidepressants trigger TrkB signaling by evoking a state associated with electroencephalographic slow-wave activity, behavioral immobility, reduced cerebral glucose...

Mapping the subcortical connectivity of the human default mode network

bioRxiv July 14, 2021 Jian Li, W. Curley, B. Guérin et al. preprint

The default mode network (DMN) mediates self-awareness and introspection, core components of human consciousness. Therapies to restore consciousness in patients with severe brain injuries have historically targeted subcortical sites in the brainstem, thalamus, hypothalamus, basal forebrain, and basal ganglia, with the goal of reactivating cortical DMN nodes. However, the subcortical...

Consciousness is supported by near-critical cortical electrodynamics

bioRxiv June 11, 2021 Daniel Toker, Ioannis Pappas, Janna D. Lendner et al. 3 citations preprint

Mounting evidence suggests that during conscious states, the electrodynamics of the cortex are poised near a critical point or phase transition, and that this near-critical behavior supports the vast flow of information through cortical networks during conscious states. Here, for the first time, we empirically identify the specific critical point near which conscious cortical dynamics operate...

A Dynamic Affective Core to bind the Contents, Context, and Value of Conscious Experience

bioRxiv May 21, 2021 K. Kishida, L. P. Sands preprint

The private and dynamic nature of conscious subjective experience poses an empirical challenge that has led neuroscience-based theories about consciousness to note the importance of ‘the hard problem’ of explaining how subjective phenomenal experience can arise from neural activity but set it aside and focus on the ‘easier’ problems associated with information representation and behavior. This...

Decrease of Functional Connectivity within the Default Mode Network by a Brief Training of Focused Attention on the Breath in Novices

bioRxiv February 12, 2021 S. Trova, Yukie Tsuji, Haruka Horiuchi et al. preprint

Experienced meditators reduce the activity of the default mode network (DMN), a brain system preferentially active when people are not engaged in specific tasks. However, the neural modulation of the DMN in novices remain largely unexplored. By using electroencephalography, we investigated the DMN functional connectivity in two groups of novices: the meditation group practiced six consecutive...

Subjective visibility report is facilitated by conscious predictions only

bioRxiv July 9, 2020 Josipa Alilovic, Heleen A. Slagter, Simon van Gaal preprint

Predictions in the visual domain have been shown to modulate conscious access. Yet, little is known about how predictions may do so and to what extent they need to be consciously implemented to be effective. To address this, we administered an attentional blink (AB) task in which target 1 (T1) identity predicted target 2 (T2) identity, while participants rated their perceptual awareness of...

Glutamate and Dysconnection in the Salience Network: Neurochemical, Effective-connectivity, and Computational Evidence in Schizophrenia

bioRxiv November 2, 2019 Roberto Limongi, P. Jeon, Michael Mackinley et al. preprint

In the dysconnection hypothesis, psychosis is caused by NMDA hypofunction resulting in aberrant network connectivity. Combining a cognitive-control task, functional magnetic resonance spectroscopy, and functional magnetic resonance imaging, we tested this hypothesis in the salience network of 20 first-episode psychosis (FEP) and 20 healthy control (HC) subjects. Across groups, glutamate...