Biology subjects

O'Daly, O.

Publications and source records attributed to O'Daly, O..

9 recordsLinked to original sources

bioRxiv2026

Shared Neural Responses and Individualised Emotional Experience: An fMRI Study of Music Listening and Anhedonia

Anhedonia, the diminished capacity to experience pleasure, is a core symptom of depressive disorders and is linked to altered reward, salience, and affective processing. However, whether individual differences in anhedonia are associated with variance in neural responses during naturalistic emotional experiences remains unclear. This study examined neural synchrony, subjective emotional similarity, and continuous anhedonia-related variation in 28 healthy young adults who listened to emotionally evocative classical music during fMRI. Participants listened to happy, sad, and neutral excerpts while providing continuous emotional ratings. Inter-subject correlation (ISC) analyses quantified voxelwise neural synchrony across the brain and within affective and reward-related regions of interest (ROIs). Continuous inter-subject representational similarity analysis (IS-RSA) tested whether pairwise neural synchrony varied with anhedonic depression symptoms, measured using the Mood and Anxiety Symptoms Questionnaire (MASQ-AD). Robust ISC was observed during music listening, particularly in bilateral auditory cortices (Heschls gyrus) and sensorimotor regions. Pairwise neural synchrony showed limited correspondence with similarity in continuous emotional subjective ratings, with significant associations primarily observed in auditory and somatosensory regions rather than classical affective regions. Anhedonia IS-RSA showed no reliable associations between MASQ-AD scores and pairwise neural synchrony across targeted affective and reward-related ROIs. These findings suggest that shared neural responses during music listening are strongest in perceptual and sensorimotor systems, whereas subjective emotional similarity and anhedonia-related variation showed limited correspondence with neural synchrony. This pattern highlights the value of continuous, naturalistic approaches for distinguishing shared stimulus-locked processing from more variable components of emotional experience.

neuroscience↗

bioRxiv2024

Transcriptional and neurochemical signatures of cerebral blood flow alterations in schizophrenia and the clinical high-risk state for psychosis

The brain integrates multiple scales of description, from the level of cells and molecules to large-scale networks and behaviour, and understanding the relationships between these layers may be fundamental to advancing our understanding of how the brain works in health and disease. Recent neuroimaging research has shown that alterations in brain function that are associated with schizophrenia spectrum disorders (SSD) are already present in young adults at clinical high-risk for psychosis (CHR-P), yet the cellular and molecular determinants of these alterations are not well understood. Here, combining regional cerebral blood flow (rCBF) data with existing transcriptomic and neurotransmitter data, we show that cell-types involved in stress response and inflammation, as well as the dopamine, acetylcholine, GABAA and NMDA receptor systems, align as shared and distinct cellular and neurochemical signatures of rCBF phenotypes in people with SSD and those at CHR-P. Decoding the biological pathways involved in neuroimaging-based psychosis phenotypes may provide a basis for the development of novel interventions.

neuroscience↗

bioRxiv2023

Anhedonia severity mediates the relationship between attentional networks recruitment and emotional blunting during music listening

Recent studies have reported atypical emotional processing in individuals with greater levels of anhedonic depressive symptoms. However, the relationship between brain networks dynamics and moment-to-moment affective responses to naturalistic paradigms, as emotions are unfolding, remains unclear. In this study, we used the unique temporal characteristics of music to investigate behavioural and brain network dynamics as a function of anhedonic depressive symptoms severity in healthy adults during an emotionally provocative music listening task. Thirty-one neurotypical participants aged 18-30 years were required to continuously rate happy, neutral and sad pieces of music whilst undergoing MRI scanning. They were also asked to fill in questionnaires assessing their levels of anhedonic depressive symptoms. Using a novel fMRI analysis method called Leading Eigenvector Dynamics Analysis (LEiDA), we found an increased probability of occurrence of attentional networks and a blunted emotional response to both happy and sad pieces of music in participants with greater levels of anhedonic depressive symptoms. More specifically, anhedonic depressive symptoms mediated the relationship between attentional networks recruitment and emotional blunting. Furthermore, the elevated recruitment of attentional networks during emotional pieces of music carried over into subsequent neutral music. Future studies are needed to investigate whether these findings could be generalised to a clinical population (i.e., Major Depressive Disorder).

neuroscience↗

bioRxiv2022

The Effects of Propofol Anaesthesia on Molecular-enriched Networks During Resting-state and Naturalistic Stimulation

Placing a patient in a state of anaesthesia is crucial for modern surgical practice. However, the mechanisms by which anaesthetic drugs, such as propofol, impart their effects on consciousness remain poorly understood. Propofol potentiates GABAergic transmission, which purportedly has direct actions on cortex as well as indirect actions via ascending neuromodulatory systems. Functional imaging studies to date have been limited in their ability to unravel how these effects on neurotransmission impact system-level dynamics of the brain. Here, we leveraged advances in multi-modal imaging, Receptor-Enriched Analysis of functional Connectivity by Targets (REACT), to investigate how different levels of propofol-induced sedation alters neurotransmission-related functional connectivity (FC), both at rest and when individuals are exposed to naturalistic auditory stimulation. Propofol increased GABA-A- and noradrenaline transporter-enriched FC within occipital and somatosensory regions respectively. Additionally, during auditory stimulation, the network related to the vesicular acetylcholine transporter showed reduced FC within the right superior temporal gyrus, regardless of level of anaesthesia, and a spatial configuration correlating with a broad range of meta-analytic measures of audition- and emotion-related cognition. In bringing together these micro- and macro-scale systems, we provide support for both direct GABAergic and indirect noradrenergic-related network changes under anaesthesia and describe a cognition-related reconfiguration of the cholinergic network, highlighting the utility of REACT to explore the molecular substrates consciousness and cognition.

neuroscience↗

bioRxiv2022

Tissue volume estimation and age prediction using rapid structural brain scans

The multicontrast EPImix sequence generates 6 contrasts, including a T1-weighted scan, in [~]1 minute. EPImix shows comparable diagnostic performance to conventional scans under qualitative clinical evaluation, and similarities in simple quantitative measures including contrast intensity. However, EPImix scans have not yet been compared to standard MRI scans using established quantitative measures. In this study, we compared conventional and EPImix-derived T1-weighted scans of 64 healthy participants using tissue volume estimates and predicted brain-age. All scans were pre-processed using the SPM12 DARTEL pipeline, generating measures of grey matter, white matter and cerebrospinal fluid volume. Brain-age was predicted using brainageR, a Gaussian process regression model previously trained on a large sample of standard T1-weighted scans. Estimates of both global and voxel-wise tissue volume showed significantly similar results between standard and EPImix-derived T1-weighted scans. Brain-age estimates from both sequences were significantly correlated, although EPImix T1-weighted scans showed a systematic offset in predictions of chronological age. Supplementary analyses suggest that this is likely caused by the reduced field of view of EPImix scans, and the use of a brain-age model trained using conventional T1-weighted scans. However, this systematic error can be corrected using additional regression of T1-predicted brain-age onto EPImix-predicted brain-age. Finally, retest EPImix scans acquired for 10 participants demonstrated high test-retest reliability in all evaluated quantitative measurements. Quantitative analysis of EPImix scans holds potential to reduce scanning time, increasing participant comfort and reducing cost, as well as to support automation of scanning, utilising active learning for faster and individually-tailored (neuro)imaging.

neuroscience↗

bioRxiv2020

The association between pain-induced autonomic reactivity and descending pain control is mediated by the periaqueductal grey

There is a strict interaction between the autonomic nervous system (ANS) and pain, which might involve descending pain modulatory mechanisms. The periaqueductal grey (PAG) is involved both in descending pain modulation and ANS, but its role in mediating this relationship has not yet been explored. Here, we sought to determine brain regions mediating ANS and descending pain control associations. 30 participants underwent Conditioned Pain Modulation (CPM) assessments, in which they rated painful pressure stimuli applied to their thumbnail, either alone or with a painful cold contralateral stimulation. Differences in pain ratings between pressure-only and pressure+cold stimuli provided a measure of descending pain control. In 18 of the 30 participants, structural scans and two functional MRI assessments, one pain-free and one during cold-pain, were acquired. Heart Rate Variability (HRV) was simultaneously recorded. Low frequency HRV (LF-HRV) and the CPM score were negatively correlated; individuals with higher LF-HRV during pain reported reductions in pain during CPM. PAG-frontal medial cortex (FMC) and PAG-rostral ventro-medial medulla (RVM) functional connectivity correlated negatively with the CPM. Importantly, PAG-FMC functional connectivity mediated the strength of HRV-CPM association. CPM response magnitude was also negatively associated with PAG and positively associated with FMC grey matter volumes. Our multi-modal approach, using behavioral, physiological and MRI measures, provides important new evidence of interactions between ANS and descending pain mechanisms. ANS dysregulation and dysfunctional descending pain modulation are characteristics of chronic pain. We suggest that further investigation of body-brain interactions in chronic pain patients may catalyse the development of new treatments.

neuroscience↗

bioRxiv2019

ExploreASL: an image processing pipeline for multi-center ASL perfusion MRI studies

Arterial spin labeling (ASL) has undergone significant development since its inception, with a focus on improving standardization and reproducibility of its acquisition and quantification. In a community-wide effort towards robust and reproducible clinical ASL image processing, we developed the software package ExploreASL, allowing standardized analyses across centers and scanners. The procedures used in ExploreASL capitalize on published image processing advancements and address the challenges of multi-center datasets with scanner-specific processing and artifact reduction to limit patient exclusion. ExploreASL is self-contained, written in MATLAB and based on Statistical Parameter Mapping (SPM) and runs on multiple operating systems. The toolbox adheres to previously defined international standards for data structure, provenance, and best analysis practice. ExploreASL was iteratively refined and tested in the analysis of >10,000 ASL scans using different pulse-sequences in a variety of clinical populations, resulting in four processing modules: Import, Structural, ASL, and Population that perform tasks, respectively, for data curation, structural and ASL image processing and quality control, and finally preparing the results for statistical analyses on both single-subject and group level. We illustrate ExploreASL processing results from three cohorts: perinatally HIV-infected children, healthy adults, and elderly at risk for neurodegenerative disease. We show the reproducibility for each cohort when processed at different centers with different operating systems and MATLAB versions, and its effects on the quantification of gray matter cerebral blood flow. ExploreASL facilitates the standardization of image processing and quality control, allowing the pooling of cohorts to increase statistical power and discover between-group perfusion differences. Ultimately, this workflow may advance ASL for wider adoption in clinical studies, trials, and practice.

neuroscience↗

bioRxiv2019

The heterogeneous functional architecture of the posteromedial cortex is associated with selective functional connectivity differences in Alzheimer’s disease

The posteromedial cortex (PMC) is a key region involved in the development and progression of Alzheimers disease (AD). Previous studies have demonstrated a heterogenous functional architecture of the region, with different subdivisions reflecting distinct connectivity profiles. However, little is understood about PMC functional connectivity and its differential vulnerability to AD pathogenesis. Using a data-driven approach, we applied a constrained independent component analysis (ICA) on healthy adults from the Human Connectome Project (HCP) to characterise the distinct functional subdivisions and unique functional-anatomic connectivity patterns of the PMC. These connectivity profiles were subsequently quantified in the Alzheimers Disease Neuroimaging Initiative (ADNI) study, to examine functional connectivity differences in (1) AD patients and cognitively normal (CN) participants and (2) the entire AD pathological spectrum, ranging from CN participants and participants with subjective memory complaints (SMC), through to those with mild cognitive impairment (MCI), and finally, patients diagnosed with AD. Our findings revealed decreased functional connectivity in the anterior precuneus, dorsal posterior cingulate cortex, and the central precuneus in AD patients compared to CN participants. Functional abnormalities in these subdivisions were also related to high amyloid burden and lower hippocampal volumes. Across the entire AD spectrum, functional connectivity of the central precuneus was associated with disease progression and specific deficits in memory and executive function. These findings provide new evidence showing that specific vulnerabilities in PMC functional connectivity are associated with large-scale network disruptions in AD and that these patterns may be useful for elucidating potential biomarkers for measuring disease progression in future work.

neuroscience↗

bioRxiv2019

Sustained perturbation in functional connectivity induced by cold pain

Functional connectivity (FC) perturbations have been reported in multiple chronic pain phenotypes, but the nature of reported changes is varied and inconsistent between cohorts. Increases and decreases in connectivity strength in task negative and positive networks, for example, the default mode and salience networks (DMN/SN), respectively, have been described, but how other networks are effected, for example, descending pain control networks, remains unknown. Whether connectivity changes relate to peripherally-mediated nociceptive afferent input, represent coping strategies or are sequelae of chronic pain, e.g. anxiety/depression, is also unknown. Here, we examined FC changes in response to experimentally-administered tonic cold pain in healthy volunteers as a means of disambiguating the nature of connectivity changes. We assessed FC prior to, during, and following tonic cold painful stimulation in four seed regions: ventromedial prefrontal cortex (vmPFC), rostral anterior insula (rAI), subgenual anterior cingulate cortex (ACC) and periaqueductal grey (PAG) and recorded subjectively reported pain using a computerised visual analogue scale. We saw DMN FC changes during painful stimulation and that inter-network communication between the rAI and sgACC seeds with the vmPFC became less anti-correlated during pain, whereas PAG-precuneus FC decreased. Pain-induced FC alterations largely persisted during a 6-minute recovery period following cessation of the painful stimulus. Observed FC changes related to the magnitude of individuals subjectively reported pain. We provide new insights into FC changes during and following tonic cold-pain and suggest that some FC changes observed in chronic pain patients may relate to the presence of an ongoing afferent peripheral drive.

neuroscience↗