Frontal GABA levels associate with musical rhythm production in healthy aging adults.

Changes in neuronal inhibition have been implicated in age-related declines in sensorimotor performance. While indirect evidence suggests that inhibitory mechanisms are also involved in rhythm entrainment, this association has not been tested. Using magnetic resonance spectroscopy, we tested the association between dorsomedial frontal GABA+/H2O concentrations and musical rhythm production in healthy younger (n = 14; 18-35) and older (n = 12; 55-79) adults, hypothesizing that lower GABA+/H2O concentrations would be associated with increased timing error, particularly on more difficult exercises, and intra-individual variability (quantified via mean successive squared difference (MSSD)).

Multidisciplinary Delphi Panel on Rehabilitation Approaches and Unmet Needs for Chronic Stroke Walking Impairment and the Role of Rhythmic Auditory Stimulation.

Introduction: Walking or gait impairment is a common consequence of stroke that persists into the chronic phase of recovery for many stroke survivors. The goals of this work were to obtain consensus from a multidisciplinary panel on current practice patterns and treatment options for walking impairment after stroke, to better understand the unmet needs for rehabilitation in the chronic phase of recovery and to explore opportunities to address them, and to discuss the potential role of rhythmic auditory stimulation (RAS) in gait rehabilitation.

Methods: A panel of eight experts specializing in neurology, physical therapy, and physiatry participated in this three-part, modified Delphi study.

Individual joint contributions to forward propulsion are not related to stability during walking in young or older adults.

Background: Older adults are less stable and walk slower than younger adults, both of which are associated with higher fall risk. Older adults use ankle musculature less and rely more on hip contributions for forward propulsion than younger adults, which has been suggested to be a protective walking strategy to increase stability. However, whether distal-to-proximal redistribution of propulsion and dynamic margin of stability are related has not been determined.

Effects of Stroboscopic Goggles on Standing Balance in the Spatiotemporal and Frequency Domains: An Exploratory Study.

Balance training paradigms have been shown to effectively reduce fall risk. Visual feedback is an important sensory mechanism for regulating postural control, promoting visual perturbations for balance training paradigms. Stroboscopic goggles, which oscillate from transparent to opaque, are a form of visual perturbation, but their effect on standing balance has not been assessed.

Factors affecting community ambulation post-stroke: a mapping review protocol.

Background: Most stroke survivors consider community ambulation an essential but unmet goal of their recovery. Historically, interventions to enhance community ambulation have focused on improving biomechanical impairments of gait; however, recent evidence suggests that biopsychosocial and environmental factors may impact community ambulation, even beyond more obvious physical impairments. The identification of factors that pose as significant facilitators or barriers to community ambulation may serve to guide stakeholders in designing relevant and evidence-based interventions for improving community ambulation post-stroke.

Passive bicycle training stimulates epiphyseal bone formation and restores bone integrity independent of locomotor recovery in a rat spinal cord injury model.

It is unknown whether activity-based physical therapy (ABPT) modalities that mobilize the paralyzed limbs improve bone integrity at the highly fracture-prone epiphyseal regions of the distal femur and proximal tibia following severe spinal cord injury (SCI). In this study, 4-mo-old skeletally mature littermate-matched male Sprague-Dawley rats received either SHAM surgery or severe contusion SCI. At 1 wk postsurgery, SCI rats were stratified to undergo no-ABPT, two 20-min bouts/day of quadrupedal bodyweight-supported treadmill training (qBWSTT), or hindlimb passive isokinetic bicycle (cycle) training, 5 days/wk for another 3 wk.

ChatGPT's Role in Gerontology Research.

Background: Chat Generative Pre-trained Transformer (ChatGPT) and other ChatBots have emerged as tools for interacting with information in manners resembling natural human speech. Consequently, the technology is used across various disciplines, including business, education, and even in biomedical sciences. There is a need to better understand how ChatGPT can be used to advance gerontology research.

Protocol for a home-based self-delivered prehabilitation intervention to proactively reduce fall risk in older adults: a pilot randomized controlled trial of transcranial direct current stimulation and motor imagery.

Background: Several changes occur in the central nervous system with increasing age that contribute toward declines in mobility. Neurorehabilitation has proven effective in improving motor function though achieving sustained behavioral and neuroplastic adaptations is more challenging. While effective, rehabilitation usually follows adverse health outcomes, such as injurious falls.

Interhemispheric inhibition and gait adaptation associations in people with multiple sclerosis.

Background: Multiple sclerosis is a neurodegenerative disease that damages the myelin sheath within the central nervous system. Axonal demyelination, particularly in the corpus callosum, impacts communication between the brain's hemispheres in persons with multiple sclerosis (PwMS). Changes in interhemispheric communication may impair gait coordination which is modulated by communication across the corpus callosum to excite and inhibit specific muscle groups.

Speed- and Endurance-Based Classifications of Community Ambulation Post-Stroke Revisited: The Importance of Location in Walking Performance Measurement.

Background: Gait speed or 6-minute walk test are frequently used to project community ambulation abilities post-stroke by categorizing individuals as household ambulators, limited, or unlimited community ambulators. However, whether improved clinically-assessed gait outcomes truly translate into enhanced real-world community ambulation remains uncertain.

Objective: This cross-sectional study aimed to examine differences in home and community ambulation between established categories of speed- and endurance-based classification systems of community ambulation post-stroke and compare these with healthy controls.

Resting state brain network segregation is associated with walking speed and working memory in older adults.

Older adults exhibit larger individual differences in walking ability and cognitive function than young adults. Characterizing intrinsic brain connectivity differences in older adults across a wide walking performance spectrum may provide insight into the mechanisms of functional decline in some older adults and resilience in others. Thus, the objectives of this study were to: (1) determine whether young adults and high- and low-functioning older adults show group differences in brain network segregation, and (2) determine whether network segregation is associated with working memory and walking function in these groups.

Prefrontal cortical activity during uneven terrain walking in younger and older adults.

Introduction: Walking in complex environments increases the cognitive demand of locomotor control; however, our understanding of the neural mechanisms contributing to walking on uneven terrain is limited. We used a novel method for altering terrain unevenness on a treadmill to investigate the association between terrain unevenness and cortical activity in the prefrontal cortex, a region known to be involved in various cognitive functions.

Methods: Prefrontal cortical activity was measured with functional near infrared spectroscopy while participants walked on a novel custom-made terrain treadmill surface across four different terrains: flat, low, medium, and high levels of unevenness.

Transcriptomics reveals transient and dynamic muscle fibrosis and atrophy differences following spinal cord injury in rats.

Background: The rate and magnitude of skeletal muscle wasting after severe spinal cord injury (SCI) exceeds most other disuse conditions. Assessing the time course of molecular changes can provide insight into the progression of muscle wasting post-SCI. The goals of this study were (1) to identify potential targets that may prevent the pathologic features of SCI in soleus muscles and (2) to establish therapeutic windows for treating these pathologic changes.

Serine racemase expression profile in the prefrontal cortex and hippocampal subregions during aging in male and female rats.

Aging is associated with a decrease in N-methyl-D-aspartate (NMDA) receptor function, which is critical for maintaining synaptic plasticity, learning, and memory. Activation of the NMDA receptor requires binding of the neurotransmitter glutamate and also the presence of co-agonist D-serine at the glycine site. The enzymatic conversion of L-serine to D-serine is facilitated by the enzyme serine racemase (SR).

Temporal Profile of Serum Neurofilament Light (NF-L) and Heavy (pNF-H) Level Associations With 6-Month Cognitive Performance in Patients With Moderate-Severe Traumatic Brain Injury.

Objective: Identification of biomarkers of cognitive recovery after traumatic brain injury (TBI) will inform care and improve outcomes. This study assessed the utility of neurofilament (NF-L and pNF-H), a marker of neuronal injury, informing cognitive performance following moderate-to-severe TBI (msTBI).

Setting: Level 1 trauma center and outpatient via postdischarge follow-up.

A conceptual framework for a neurophysiological basis of art therapy for PTSD.

Post-traumatic stress disorder (PTSD) is a heterogeneous condition that affects many civilians and military service members. Lack of engagement, high dropout rate, and variable response to psychotherapy necessitates more compelling and accessible treatment options that are based on sound neuroscientific evidence-informed decision-making. Art therapy incorporates elements proven to be effective in psychotherapy, such as exposure, making it a potentially valuable treatment option.

Parallel Cerebrospinal Fluid and Serum Temporal Profile Assessment of Axonal Injury Biomarkers Neurofilament-Light Chain and Phosphorylated Neurofilament-Heavy Chain: Associations With Patient Outcome in Moderate-Severe Traumatic Brain Injury.

Neurofilament-light chain (NF-L) and phosphorylated neurofilament-heavy chain (pNF-H) are axonal proteins that have been reported as potential diagnostic and prognostic biomarkers in traumatic brain injury (TBI). However, detailed temporal profiles for these proteins in blood, and interrelationships in the acute and chronic time periods post-TBI have not been established. Our objectives were: 1) to characterize acute-to-chronic serum NF-L and pNF-H profiles after moderate-severe TBI, as well as acute cerebrospinal fluid (CSF) levels; 2) to evaluate CSF and serum NF-L and pNF-H associations with each other; and 3) to assess biomarker associations with global patient outcome using both the Glasgow Outcome Scale-Extended (GOS-E) and Disability Rating Scale (DRS).

Activity in the pontine reticular nuclei scales with handgrip force in humans.

The neural pathways that contribute to force production in humans are currently poorly understood, as the relative roles of the corticospinal tract and brainstem pathways, such as the reticulospinal tract (RST), vary substantially across species. Using functional magnetic resonance imaging (fMRI), we aimed to measure activation in the pontine reticular nuclei (PRN) during different submaximal handgrip contractions to determine the potential role of the PRN in force modulation. Thirteen neurologically intact participants (age: 28 ± 6 yr) performed unilateral handgrip contractions at 25%, 50%, 75% of maximum voluntary contraction during brain scans.

MicroRNAs as biomarkers of brain injury in neonatal encephalopathy: an observational cohort study.

Neonatal Encephalopathy (NE) is a major cause of lifelong disability and neurological complications in affected infants. Identifying novel diagnostic biomarkers in this population may assist in predicting MRI injury and differentiate neonates with NE from those with low-cord pH or healthy neonates and may help clinicians make real-time decisions. To compare the microRNA (miRNA) profiles between neonates with NE, healthy controls, and neonates with low cord pH.

Visuospatial cognition predicts performance on an obstructed vision obstacle walking task in older adults.

Walking performance and cognitive function demonstrate strong associations in older adults, with both declining with advancing age. Walking requires the use of cognitive resources, particularly in complex environments like stepping over obstacles. A commonly implemented approach for measuring the cognitive control of walking is a dual-task walking assessment, in which walking is combined with a second task.

Aptamer Technologies in Neuroscience, Neuro-Diagnostics and Neuro-Medicine Development.

Aptamers developed using in vitro Systematic Evolution of Ligands by Exponential Enrichment (SELEX) technology are single-stranded nucleic acids 10-100 nucleotides in length. Their targets, often with specificity and high affinity, range from ions and small molecules to proteins and other biological molecules as well as larger systems, including cells, tissues, and animals. Aptamers often rival conventional antibodies with improved performance, due to aptamers' unique biophysical and biochemical properties, including small size, synthetic accessibility, facile modification, low production cost, and low immunogenicity.