Biology subjects

Stringer, M.

Publications and source records attributed to Stringer, M..

3 recordsLinked to original sources

bioRxiv2023

Self-regulation of attention in children in a virtual classroom environment: a feasibility study

Attention is a crucial cognitive function that enables us to selectively focus on relevant information from the surrounding world to achieve our goals. When this sustained ability to direct attention is impaired, individuals face significant challenges in everyday life. This is the case for children with Attention Deficit Hyperactivity Disorder (ADHD), a complex neurodevelopmental disorder characterized by impulsive and inattentive behavior. While psychostimulant medications are currently the most effective treatment for ADHD, they often come with unwanted side effects, and sustaining the benefits can be difficult for many children. Therefore, it is imperative to explore non-pharmacological treatments that offer longer-lasting outcomes. Here, we proposed a groundbreaking protocol that combines electroencephalography-based neurofeedback (EEG-NFB) with virtual reality (VR) as an innovative approach to treating attention deficits. By integrating a virtual classroom environment, we aimed to enhance the transferability of attentional control skills while simultaneously increasing motivation and interest among children. The present study demonstrated the feasibility of this approach through an initial assessment involving a small group of healthy children, showcasing its potential for future evaluation in children diagnosed with ADHD. Encouragingly, the preliminary findings indicated high engagement rates and positive feedback from the children participating in the study. Additionally, the pre-and post-protocol assessments using EEG and fMRI recordings appeared to converge towards an improvement in attentional function. Although further validation is required to establish the efficacy of the proposed protocol, it represents a significant advancement in the field of neurofeedback therapy for ADHD. The integration of EEG-NFB and VR presents a novel avenue for enhancing attentional control and addressing behavioral challenges in children with ADHD.

neuroscience↗

bioRxiv2021

An intrinsic endothelial dysfunction causes cerebral small vessel disease

Small Vessel Disease (SVD) is the leading cause of vascular dementia, causes a quarter of strokes, and worsens stroke outcomes(1, 2). The disease is characterised by cerebral small vessel and white matter pathology, but the underlying mechanisms are poorly understood. Classically, the microvascular and tissue damage has been considered secondary to extrinsic factors, such as hypertension, consisting of microvessel stiffening, impaired vasoreactivity and blood-brain barrier dysfunction identified in human sporadic SVDs. However, increasing evidence points to an underlying vulnerability to SVD-related brain damage, not just extrinsic factors. Here, in a novel normotensive transgenic rat model where the phospholipase flippase Atp11b is deleted, we show pathological, imaging and behavioural changes typical of those in human sporadic SVD, but that occur without hypertension. These changes are due to an intrinsic endothelial cell dysfunction, identified in vessels of the brain white matter and the retina, with pathological evidence of vasoreactivity and blood-brain barrier deficits, which precipitate a secondary maturation block in oligodendroglia and myelin disruption around the small vessels. This highlights that an intrinsic endothelial dysfunction may underlie vulnerability to human sporadic SVD, providing alternative therapeutic targets to prevent a major cause of stroke and dementia.

neuroscience↗

bioRxiv2019

Intracranial functional haemodynamic relationships in patients with cerebral small vessel disease

BackgroundCerebral small vessel disease (SVD) is a major cause of stroke and dementia. The underlying cerebrovascular dysfunction is poorly understood. We investigated cerebrovascular reactivity, blood flow, vascular and cerebrospinal fluid (CSF) pulsatility, and their independent relationship to SVD features, in patients with minor ischaemic stroke and MRI evidence of SVD.\n\nMethodsWe recruited patients with minor ischaemic stroke and assessed CVR using Blood Oxygen Level Dependent (BOLD) MRI during a hypercapnic challenge, cerebral blood flow, vascular and CSF pulsatility using phase contrast MRI, and structural MR brain imaging to quantify white matter hyperintensities (WMH) and perivascular spaces (PVS). We quantified CVR in seven white matter and six subcortical grey matter regions, measured blood flow in carotid and vertebral arteries, intracranial venous sinuses, internal jugular veins and CSF flow at the aqueduct and foramen magnum. We used multiple regression to identify SVD features, blood flow and pulsatility parameters associated with CVR, controlling for patient characteristics.\n\nResultsIn 53 of 60 patients with complete data (age 68.0{+/-}8.8, 74% male, 75% hypertensive), CVR in grey and white matter decreased with increasing blood pressure (BP, respectively -0.001%/mmHg, p=0.01 and -0.006%/mmHg, p=0.01, per mmHg increase in BP). After controlling for age, gender and systolic BP, white matter CVR decreased with increasing WMF volume (-0.01%/mmHg per log10 increase in WMH volume, p=0.02) and basal ganglia PVS (-0.01%/mmHg per point increase in PVS score, p=0.02). White matter CVR decreased with increasing venous pulsatility (superior sagittal sinus -0.03%/mmHg, p=0.02, per unit increase in pulsatility index) but not with cerebral blood flow (p=0.58). Lower foramen magnum CSF stroke volume was associated with worse white matter CVR (0.04%/mmHg per ml increase in stroke volume, p=0.04) and increased basal ganglia PVS.\n\nConclusionsContemporaneous assessment of CVR, intracranial vascular and CSF pulsatility demonstrates important interrelationships of these vascular functions in humans. Decreased CVR, increased venous pulsatility and reduced foramen magnum CSF stroke volume suggests that dynamic vascular dysfunctions underpin PVS dysfunction and WMH development. Improved understanding of microvascular dysfunction and CSF dynamics offers new intervention targets to reduce SVD lesion development and their impact on cognitive dysfunction and stroke.

neuroscience↗