Neurophysiological correlates of modifiable dementia risk factors in cognitively unimpaired older adults.

The 2024 Lancet Commission on Dementia estimates that up to 45% of dementia cases could be prevented by addressing modifiable risk factors, emphasizing both prevention opportunities and the need to understand the biological mechanisms. This study investigated neurophysiological mechanisms underlying modifiable dementia risk factors in cognitively unimpaired older adults. Seventy-nine cognitively unimpaired older adults underwent magnetic resonance imaging brain scans, with spectroscopy measurements taken from the sensorimotor cortex (SMC) and prefrontal cortex (PFC), using a Hadamard Encoding and Reconstruction of MEGA-Edited Spectroscopy sequence, optimized for measuring GABA+.

Differential neural responses to body image-related cyberbullying in adolescent females.

Body image-related cyberbullying (BRC), which targets an individual's body shape, weight, and/or size, is associated with body dissatisfaction and maladaptive eating behaviours among adolescent females. However, its neurobiological mechanisms remain unclear. Using functional magnetic resonance imaging, we examined neural responses to BRC stimuli in 26 females (14-18 years; Mage = 15.

Circulating biomarkers and neuroanatomical brain structures differ in older adults with and without post-traumatic stress disorder.

The aim of this study was to advance post-traumatic stress disorder (PTSD) understanding in older adults (48-77 years) by determining if circulating cytokines (IL-1β, IL-2, IL-4, IL-6, IL-12p70, IL17A and TNFα), brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF-A) and neuroanatomical brain volumes (grey and white matter, hippocampus, and amygdala) significantly differed in those with versus without PTSD. While none of the tested cytokines showed a significant difference, serum BDNF and VEGF-A levels were found to be significantly higher in the PTSD cohort. The assay used for BDNF quantification was important, with differences in general BDNF detected, but not when pro- and mature BDNF were measured specifically.

Characterising mental wellbeing and associations with subcortical grey matter volume at short intervals in early adolescence.

This temporally rich, longitudinal study of early adolescents (N = 88, 277 datasets, 12-13 years) investigated the relationship between bilateral subcortical grey matter volume (GMV) in the hippocampus, amygdala, accumbens-area, caudate, putamen and pallidum with self-reported mental wellbeing at four timepoints, across 12 months. Generalised Estimating Equations (GEE) revealed (1) higher 'total wellbeing' was associated with smaller left caudate and larger left accumbens-area; (2) higher eudaimonic wellbeing was associated with smaller left caudate and larger right caudate; and (3) higher hedonic wellbeing was associated with larger left accumbens-area. Further analyses and plots highlighted different associations between GMV and wellbeing for adolescents who consistently experienced 'moderate-to-flourishing' wellbeing (n = 63, 201 datasets), compared with those who experienced 'languishing' wellbeing at any timepoint (n = 25, 76 datasets).

Modifiable dementia risk associated with smaller white matter volume and altered 1/f aperiodic brain activity: cross-sectional insights from the LEISURE study.

Background: The rising prevalence of dementia necessitates identifying early neurobiological markers of dementia risk. Reduced cerebral white matter volume and flattening of the slope of the electrophysiological 1/f spectral power distribution provide neurobiological markers of brain ageing alongside cognitive decline. However, their association with modifiable dementia risk remains to be understood.

Structural brain correlates of sustained attention in healthy ageing: Cross-sectional findings from the LEISURE study.

Sustained attention is important for maintaining cognitive function and autonomy during ageing, yet older people often show reductions in this domain. The role of the underlying neurobiology is not yet well understood, with most neuroimaging studies primarily focused on fMRI. Here, we utilise sMRI to investigate the relationships between age, structural brain volumes and sustained attention performance.

Resting-state EEG correlates of sustained attention in healthy ageing: Cross-sectional findings from the LEISURE study.

While structural and biochemical brain changes are well-documented in ageing, functional neuronal network differences, as indicated by electrophysiological markers, are less clear. Moreover, age-related changes in sustained attention and their associated electrophysiological correlates are still poorly understood. To address this, we analysed cross-sectional baseline electroencephalography (EEG) and cognitive data from the Lifestyle Intervention Study for Dementia Risk Reduction (LEISURE).

Understanding Wellbeing Profiles According to White Matter Structural Connectivity Sub-types in Early Adolescents: The First Hundred Brains Cohort from the Longitudinal Adolescent Brain Study.

Wellbeing is protective against the emergence of psychopathology. Neurobiological markers associated with mental wellbeing during adolescence are important to understand. Limited research has examined neural networks (white matter tracts) and mental wellbeing in early adolescence specifically.

A short-interval longitudinal study of associations between psychological distress and hippocampal grey matter in early adolescence.

This study of Australian adolescents (N = 88, 12-13-years-old) investigated the relationship between hippocampal grey matter volume (GMV) and self-reported psychological distress (K10) at four timepoints, across 12 months. Participants were divided into two groups; those who had K10 scores between 10 and 15 for all four timepoints were categorised as "low distress" (i.e.

The LEISURE Study: A Longitudinal Randomized Controlled Trial Protocol for a Multi-Modal Lifestyle Intervention Study to Reduce Dementia Risk in Healthy Older Adults.

Dementia is understood to arise from a mixed etiology, enveloping chronic inflammatory and vascular impacts on the brain, driven by a constellation of modifiable risk factors which are largely mediated by lifestyle-related behaviors. These risk factors manifest over a prolonged preclinical period and account for up to 40% of the population attributable risk for dementia, representing viable targets for early interventions aimed at abating disease onset and progression. Here we outline the protocol for a 12-week randomized control trial (RCT) of a multimodal Lifestyle Intervention Study for Dementia Risk Reduction (LEISURE), with longitudinal follow-up at 6-months and 24-months post-intervention.

Repeated unilateral handgrip contractions alter functional connectivity and improve contralateral limb response times.

In humans, motor learning is underpinned by changes in sensorimotor network functional connectivity (FC). Unilateral contractions increase FC in the ipsilateral primary motor cortex (M1) and supplementary motor area (SMA); areas involved in motor planning and execution of the contralateral hand. Therefore, unilateral contractions are a promising approach to augment motor performance in the contralateral hand.

Sex differences in brain volumes and psychological distress: The first hundred brains cohort of the longitudinal adolescent brain study.

Neurodevelopment during early childhood and adolescence are recognised as critical periods, with potential life-long lasting impacts on mental health and wellbeing. The time-frame of these neurodevelopmental changes also correspond to one in five individuals aged 9-17 years old being diagnosed with a mental health condition. Furthermore, sex-based differences in the diagnosed prevalence of mental health conditions are also well characterised and can be leveraged to differentiate development of brain structures between sexes throughout childhood and adolescence.

White Matter Changes in Cervical Dystonia Relate to Clinical Effectiveness of Botulinum Toxin Treatment.

In a previous report showing white matter microstructural hemispheric asymmetries medial to the pallidum in focal dystonias, we showed preliminary evidence that this abnormality was reduced 4 weeks after botulinum toxin (BTX) injections. In the current study we report the completed treatment study in a full-size cohort of CD patients ( = 14). In addition to showing a shift toward normalization of the hemispheric asymmetry, we evaluated clinical relevance of these findings by relating white matter changes to degree of symptom improvement.

Neurochemical changes underpinning the development of adjunct therapies in recovery after stroke: A role for GABA?

Stroke is a leading cause of long-term disability, with around three-quarters of stroke survivors experiencing motor problems. Intensive physiotherapy is currently the most effective treatment for post-stroke motor deficits, but much recent research has been targeted at increasing the effects of the intervention by pairing it with a wide variety of adjunct therapies, all of which aim to increase cortical plasticity, and thereby hope to maximize functional outcome. Here, we review the literature describing neurochemical changes underlying plasticity induction following stroke.

Thalamic Volume Is Reduced in Cervical and Laryngeal Dystonias.

Background: Dystonia, a debilitating movement disorder characterized by abnormal fixed positions and/or twisting postures, is associated with dysfunction of motor control networks. While gross brain lesions can produce secondary dystonias, advanced neuroimaging techniques have been required to identify network abnormalities in primary dystonias. Prior neuroimaging studies have provided valuable insights into the pathophysiology of dystonia, but few directly assessed the gross volume of motor control regions, and to our knowledge, none identified abnormalities common to multiple types of idiopathic focal dystonia.