A5004824400- Neural dynamics and brain function
- Functional Brain Connectivity Studies
- Neuroscience and Neuropharmacology Research
- EEG and Brain-Computer Interfaces
- Neuroscience and Neural Engineering
- Color perception and design
- Advanced MRI Techniques and Applications
- Treatment of Major Depression
- Neuroscience and Music Perception
- Olfactory and Sensory Function Studies
- Genetic Associations and Epidemiology
- Genomics and Rare Diseases
- Epilepsy research and treatment
- Anesthesia and Sedative Agents
- Advanced Neuroimaging Techniques and Applications
- Menstrual Health and Disorders
- Muscle activation and electromyography studies
- Biochemical Analysis and Sensing Techniques
- Biomedical Text Mining and Ontologies
- Transcranial Magnetic Stimulation Studies
- Parkinson's Disease Mechanisms and Treatments
- Medical History and Innovations
- Migraine and Headache Studies
- Neuroendocrine regulation and behavior
- Digestive system and related health
University of Exeter
2021-2025
Singer (United States)
2022
Cardiff University
2012-2021
MRC Cognition and Brain Sciences Unit
2019-2021
Cambridge University Hospitals NHS Foundation Trust
2020
Neuroscience Research Australia
2019
Glasgow Royal Infirmary
2011
University of Glasgow
2011
Following the discovery of antidepressant properties ketamine, there has been a recent resurgence in interest this NMDA receptor antagonist. Although detailed animal models molecular mechanisms underlying ketamine9s effects have emerged, are few MEG/EEG studies examining acute subanesthetic ketamine infusion man. We recorded 275 channel MEG two experiments (<i>n</i> = 25 human males) infusion. power spectra revealed rich set significant oscillatory changes compared with placebo sessions,...
The variability in the response to antipsychotic medication schizophrenia may reflect between-patient differences neurobiology. Recent cross-sectional neuroimaging studies suggest that a poorer therapeutic is associated with relatively normal striatal dopamine synthesis capacity but elevated anterior cingulate cortex (ACC) glutamate levels. We sought test whether these measures can differentiate patients psychosis who are responsive from those nonresponsive multicenter study. 1H-magnetic...
Abstract Background Microdosing psychedelics is a phenomenon with claimed cognitive benefits that are relatively untested clinically. Pre-clinically, have demonstrated enhancing effects on neuroplasticity, which cannot be measured directly in humans, but may indexed by non-invasive electroencephalography (EEG) paradigms. This study used visual long-term potentiation (LTP) EEG paradigm to test the of microdosed lysergic acid diethylamide (LSD) neural plasticity, both acutely while drug and...
The dysconnection hypothesis of schizophrenia (SZ) proposes that psychosis is best understood in terms aberrant connectivity. Specifically, it suggests dysconnectivity arises through synaptic modulation associated with deficits GABAergic inhibition, excitation-inhibition balance and disturbances high-frequency oscillations. Using a computational model combined graded-difficulty visual orientation discrimination paradigm, we demonstrate that, SZ, perceptual performance determined by the...
The ability to quantify synaptic function at the level of cortical microcircuits from non-invasive data would be enormously useful in study neuronal processing humans and pathophysiology that attends many neuropsychiatric disorders. Here, we provide proof principle one can estimate inter-and intra-laminar interactions among specific populations using induced gamma responses visual cortex human subjects – dynamic causal modelling based upon canonical microcircuit (CMC; a simplistic model...
The clinical syndromes caused by frontotemporal lobar degeneration are heterogeneous, including the behavioural variant dementia (bvFTD) and progressive supranuclear palsy. Although pathologically distinct, they share many behavioural, cognitive physiological features, which may in part arise from common deficits of major neurotransmitters such as γ-aminobutyric acid (GABA). Here, we quantify GABAergic impairment its restoration with dynamic causal modelling a double-blind placebo-controlled...
Abstract INTRODUCTION We examined how abnormal prefrontal neurophysiology and changes in gamma‐aminobutyric acid‐ergic (GABAergic) neurotransmission contribute to behavioral impairments disorders associated with frontotemporal lobar degeneration (FTLD). METHODS recorded magnetoencephalography during an adaptive visuomotor task from 11 people behavioral‐variant dementia, progressive supranuclear palsy, 20 age‐matched controls. used tiagabine, a acid (GABA) re‐uptake inhibitor, as...
To bridge the gap between preclinical cellular models of disease and in vivo imaging human cognitive network dynamics, there is a pressing need for informative biophysical models. Here we assess dynamic causal (DCM) cortical responses, as generative magnetoencephalographic observations during an auditory oddball roving paradigm healthy adults. This induces robust perturbations that permeate frontotemporal networks, including evoked 'mismatch negativity' response transiently induced...
Abstract Fluctuations in gonadal hormones over the course of menstrual cycle are known to cause functional brain changes and thought modulate balance cortical excitation inhibition. Animal research has shown this occurs primarily via major metabolite progesterone, allopregnanolone, its action as a positive allosteric modulator GABA A receptor. Our study used EEG record gamma oscillations induced visual cortex using stationary moving gratings. Recordings took place during twenty females’...
Abstract The analysis of neural circuits can provide crucial insights into the mechanisms neurodegeneration and dementias, offer potential quantitative biological tools to assess novel therapeutics. Here we use behavioral variant frontotemporal dementia (bvFTD) as a model disease. We demonstrate that inversion canonical microcircuit models noninvasive human magnetoencephalography, using dynamic causal modeling, identify regional- laminar-specificity bvFTD pathophysiology, their parameters...
Widespread structural and functional brain network changes have been shown in Juvenile Myoclonic Epilepsy (JME) despite normal clinical neuroimaging. We sought to better define these using magnetoencephalography (MEG) source space connectivity analysis for optimal neurophysiological anatomical localisation.We consecutively recruited 26 patients with JME who underwent resting state MEG recording, along age-and-sex matched controls. Whole was determined through correlation of Automated...
Abstract Revealing the acute cortical pharmacodynamics of an antidepressant dose ketamine in humans with depression is key to determining specific mechanism(s) action for alleviating symptoms. While downstream effects are characterised by increases plasticity and reductions depressive symptoms—it response brain that triggers this cascade events. Computational modelling interlaminar cortico-cortical connectivity receptor dynamics provide opportunity interrogate question using human...
Motivation: Advances in MRI have increased our understanding of the human brain but are frequently limited by single modality study designs. Combining data from multiple modalities/MR contrasts can enhance complex multi-scale neural relationships that underpin behaviour. Goal(s): Our goal was to create an open-access multi-scale, multi-modal imaging database healthy brain. Approach: The Welsh Advanced Neuroimaging Database (WAND) includes micro and macro-structural, functional spectroscopic...
Electroencephalography and magnetoencephalography (MEG) studies have identified alterations in gamma-band (30-80 Hz) cortical activity schizophrenia mood disorders, consistent with neural models of disturbed glutamate (and GABA) neuron influence over pyramidal cells. Genetic evidence suggests specific deficits GABA-A receptor function schizoaffective bipolar disorder (SABP), a clinical syndrome features both schizophrenia. This study investigated gamma oscillations this under-researched...
Cortical recordings of task-induced oscillations following subanaesthetic ketamine administration demonstrate alterations in amplitude, including increases at high-frequencies (gamma) and reductions low frequencies (theta, alpha). To investigate the population-level interactions underlying these changes, we implemented a thalamo-cortical model (TCM) capable recapitulating broadband spectral responses. Compared with an existing cortex-only 4-population model, Bayesian Model Selection...
Synaptic loss occurs early in many neurodegenerative diseases and contributes to cognitive impairment even the absence of gross atrophy. Currently, for human disease there are few formal models explain how cortical networks underlying cognition affected by synaptic loss. We advocate that biophysical neurophysiology offer both a bridge from preclinical clinical pathology quantitative assays experimental medicine. Such can also disclose hidden neuronal dynamics generating neurophysiological...
Abstract Neuronal oscillations in the gamma frequency range play an important role stimulus processing brain. The of these can vary widely between participants and is strongly genetically determined, but cause this variability not understood. Previous studies have reported correlations individual differences concentration inhibitory neurotransmitter, gamma‐aminobutyric acid (GABA), as well with age primary visual cortex (V1) area thickness. This study assessed relationships all variables...
Abstract The impairment of behavioural control is a characteristic feature disorders associated with frontotemporal lobar degeneration (FTLD). Behavioural disinhibition and impulsivity in these are linked to abnormal neurophysiology the frontal lobe, such as loss beta-band power changes prefrontal GABAergic neurotransmission. Here we test hypothesis that pharmacological increase GABA would concurrently improve cortical adaptive people behavioural-variant dementia (bvFTD), progressive...
Neuroplasticity is essential to learning and memory in the brain; it has therefore also been implicated numerous neurological psychiatric disorders, making measuring state of neuroplasticity foremost importance clinical neuroscience. Long-term potentiation (LTP) a key mechanism studied extensively, invasively non-human animals. Translation human application largely relies on validation non-invasive measures LTP. The current study presents generative thalamocortical computational model visual...
Studying changes in cortical oscillations can help elucidate the mechanistic link between receptor physiology and clinical effects of anaesthetic drugs. Propofol, a GABA-ergic drug produces divergent on visual activity: increasing induced gamma-band responses (GBR) while decreasing evoked responses. Dexmedetomidine, an α2- adrenergic agonist, differs from sedatives both mechanistically clinically as it allows easy arousability deep sedation with less cognitive side-effects. Here we use...
Abstract The analysis of neural circuits can provide critical insights into the mechanisms neurodegeneration and dementias, offer potential quantitative biological tools to assess novel therapeutics. Here we use behavioural variant frontotemporal dementia (bvFTD) as a model disease. We demonstrate that inversion canonical microcircuit models non-invasive human magnetoecphalography identify regional- laminar-specificity bvFTD pathophysiology, their parameters accurately differentiate patients...
As the most abundant inhibitory neurotransmitter in mammalian brain, γ-aminobutyric acid (GABA) plays a crucial role shaping frequency and amplitude of oscillations, which suggests for GABA topography functional connectivity activity. This study explored effects pharmacologically blocking reuptake (increasing local concentrations) using transporter 1 (GAT1) blocker, tiagabine (15 mg). In placebo-controlled crossover design, we collected resting magnetoencephalography (MEG) recordings from 15...
Abstract Synaptic loss occurs early in many neurodegenerative diseases and contributes to cognitive impairment even the absence of gross atrophy. Currently, for human disease there are few formal models explain how cortical networks underlying cognition affected by synaptic loss. We advocate that biophysical neurophysiology offer both a bridge from clinical preclinical pathology, quantitative assays experimental medicine. Such can also disclose hidden neuronal dynamics generating...