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Frontiers in Psychology 2023Physical exercise can improve cognitive function, and the degree of impact on cognitive function is related to exercise modality, intensity, and duration. However, few...
INTRODUCTION
Physical exercise can improve cognitive function, and the degree of impact on cognitive function is related to exercise modality, intensity, and duration. However, few studies have been conducted on the effects of competitive sports on cognitive function. The 1,500 m freestyle is the longest pool-based swimming event in the Olympic Games. This study explores the effects of 1,500 m freestyle at maximal speed on athletes' cognitive function and analyzes the potential mechanism of cognitive function reduction in freestyle at maximal speed from the perspective of hemoglobin oxygenation difference (Hbdiff).
METHODS
A total of 13 male university swimmers were required to take part in a 1,500 m freestyle competition, swimming at maximal speed. The relevant indicators, including cognitive function and freestyle at maximal speed, before and after the competition were tested and analyzed. Cognitive function was assessed using the Schulte grid test (SGT), the trail-making test (TMT), and the digit span test (DST). The neurobiological characteristics of cognitive function, such as the prefrontal cortex (PFC), response time (RT), and accuracy rate (ACC), were tested using functional near-infrared spectroscopy (fNIRS).
RESULTS
A significant decrease in scores for SGT, TMT, and digit span test-backward (DST-B) ( < 0.01). Oxygenated hemoglobin (Oxy-Hb) concentrations in the right frontopolar area (R-FPA) of brain channels 8 ( < 0.01) and 9 (CH8, 9) ( < 0.05), the right dorsolateral prefrontal cortex (R-DLPFC) CH10 ( < 0.05), and the middle dorsolateral prefrontal cortex (M-DLPFC) CH18 ( < 0.01) were significantly altered, and the right area of the brain was activated. The total Oxy-Hb concentrations in the regions of interest (ROIs) of R-FPA, R-DLFPC, and M-DLFPC were changed significantly ( < 0.01).
DISCUSSION
The exhaustive performance of a 1,500 m freestyle event resulted in both physical fatigue and a decline in cognitive function. This decline may be attributed to the activation of specific regions of interest, namely the FPA, DLPFC, and M-DLPFC, within the prefrontal cortex (PFC), as well as alterations in functional connectivity.
PubMed: 38125859
DOI: 10.3389/fpsyg.2023.1283585 -
Cell Regeneration (London, England) Jul 2023Deer antlers are the only known mammalian organ that, once lost, can fully grow back naturally. Hence, the antler offers a unique opportunity to learn how nature has... (Review)
Review
Deer antlers are the only known mammalian organ that, once lost, can fully grow back naturally. Hence, the antler offers a unique opportunity to learn how nature has solved the problem of mammalian epimorphic regeneration (EpR). Comprehensive comparisons amongst different types of EpR reveal that antler renewal is fundamentally different from that in lower vertebrates such as regeneration of the newt limb. Surprisingly, antler renewal is comparable to wound healing over a stump of regeneration-incompetent digit/limb, bone fracture repair, and to a lesser extent to digit tip regeneration in mammals. Common to all these mammalian cases of reaction to the amputation/mechanical trauma is the response of the periosteal cells at the distal end/injury site with formation of a circumferential cartilaginous callus (CCC). Interestingly, whether the CCC can proceed to the next stage to transform to a blastema fully depends on the presence of an interactive partner. The actual form of the partner can vary in different cases with the nail organ in digit tip EpR, the opposing callus in bone fracture repair, and the closely associated enveloping skin in antler regeneration. Due to absence of such an interactive partner, the CCC of a mouse/rat digit/limb stump becomes involuted gradually. Based on these discoveries, we created an interactive partner for the rat digit/limb stump through surgically removal of the interposing layers of loose connective tissue and muscle between the resultant CCC and the enveloping skin after amputation and by forcefully bonding two tissue types tightly together. In so doing partial regeneration of the limb stump occurred. In summary, if EpR in humans is to be realized, then I envisage that it would be more likely in a manner akin to antler regeneration rather to that of lower vertebrates such as newt limbs.
PubMed: 37490254
DOI: 10.1186/s13619-023-00169-4 -
JAMA Network Open Aug 2023Understanding how socioeconomic factors are associated with cognitive aging is important for addressing health disparities in Alzheimer disease.
IMPORTANCE
Understanding how socioeconomic factors are associated with cognitive aging is important for addressing health disparities in Alzheimer disease.
OBJECTIVE
To examine the association of neighborhood disadvantage with cognition among a multiethnic cohort of older adults.
DESIGN, SETTING, AND PARTICIPANTS
In this cross-sectional study, data were collected between September 1, 2017, and May 31, 2022. Participants were from the Health and Aging Brain Study-Health Disparities, which is a community-based single-center study in the Dallas/Fort Worth area of Texas. A total of 1614 Mexican American and non-Hispanic White adults 50 years and older were included.
EXPOSURE
Neighborhood disadvantage for participants' current residence was measured by the validated Area Deprivation Index (ADI); ADI Texas state deciles were converted to quintiles, with quintile 1 representing the least disadvantaged area and quintile 5 the most disadvantaged area. Covariates included age, sex, and educational level.
MAIN OUTCOMES AND MEASURES
Performance on cognitive tests assessing memory, language, attention, processing speed, and executive functioning; measures included the Spanish-English Verbal Learning Test (SEVLT) Learning and Delayed Recall subscales; Wechsler Memory Scale, third edition (WMS-III) Digit Span Forward, Digit Span Backward, and Logical Memory 1 and 2 subscales; Trail Making Test (TMT) parts A and B; Digit Symbol Substitution Test (DSST); Letter Fluency; and Animal Naming. Raw scores were used for analyses. Associations between neighborhood disadvantage and neuropsychological performance were examined via demographically adjusted linear regression models stratified by ethnic group.
RESULTS
Among 1614 older adults (mean [SD] age, 66.3 [8.7] years; 980 women [60.7%]), 853 were Mexican American (mean [SD] age, 63.9 [7.9] years; 566 women [66.4%]), and 761 were non-Hispanic White (mean [SD] age, 69.1 [8.7] years; 414 women [54.4%]). Older Mexican American adults were more likely to reside in the most disadvantaged areas (ADI quintiles 3-5), with 280 individuals (32.8%) living in ADI quintile 5, whereas a large proportion of older non-Hispanic White adults resided in ADI quintile 1 (296 individuals [38.9%]). Mexican American individuals living in more disadvantaged areas had worse performance than those living in ADI quintile 1 on 7 of 11 cognitive tests, including SEVLT Learning (ADI quintile 5: β = -2.50; 95% CI, -4.46 to -0.54), SEVLT Delayed Recall (eg, ADI quintile 3: β = -1.11; 95% CI, -1.97 to -0.24), WMS-III Digit Span Forward (eg, ADI quintile 4: β = -1.14; 95% CI, -1.60 to -0.67), TMT part A (ADI quintile 5: β = 7.85; 95% CI, 1.28-14.42), TMT part B (eg, ADI quintile 5: β = 31.5; 95% CI, 12.16-51.35), Letter Fluency (ADI quintile 4: β = -2.91; 95% CI, -5.39 to -0.43), and DSST (eg, ADI quintile 5: β = -4.45; 95% CI, -6.77 to -2.14). In contrast, only non-Hispanic White individuals living in ADI quintile 4 had worse performance than those living in ADI quintile 1 on 4 of 11 cognitive tests, including SEVLT Learning (β = -2.35; 95% CI, -4.40 to -0.30), SEVLT Delayed Recall (β = -0.95; 95% CI, -1.73 to -0.17), TMT part B (β = 15.95; 95% CI, 2.47-29.44), and DSST (β = -3.96; 95% CI, -6.49 to -1.43).
CONCLUSIONS AND RELEVANCE
In this cross-sectional study, aging in a disadvantaged area was associated with worse cognitive functioning, particularly for older Mexican American adults. Future studies examining the implications of exposure to neighborhood disadvantage across the life span will be important for improving cognitive outcomes in diverse populations.
Topics: Female; Humans; Cognition; Cross-Sectional Studies; Executive Function; Mexican Americans; White; Male; Middle Aged; Aged; Neighborhood Characteristics; United States
PubMed: 37647071
DOI: 10.1001/jamanetworkopen.2023.25325 -
Brain Sciences Aug 2023The development of Alzheimer's disease (AD) is influenced by sex hormones-estrogens and androgens in particular. However, the impact of prenatal sex hormone exposure is...
The development of Alzheimer's disease (AD) is influenced by sex hormones-estrogens and androgens in particular. However, the impact of prenatal sex hormone exposure is less clear; very few investigations have examined the relationship between the second-to-fourth digit length ratio (2D:4D), a putative proxy for the ratio of prenatal estrogens to androgens, and AD, with inconsistent results among the few that have. Therefore, we aimed to investigate this relationship using methodologically robust metrics. In a 2 (sex) × 4 (group) MANOVA incorporating 108 participants (30 AD patients, 19 patients with tauopathy but no amyloidopathy, 31 clinical and 28 healthy age- and education-matched controls), the effects of sex and group on the dependent variables right and left 2D:4D were examined. We also explored the association between 2D:4D and the severity of AD symptoms assessed via neuropsychological examination. We did not find any significant differences in the right- and left-hand 2D:4D between patients with AD and the other groups; no significant associations between 2D:4D and neuropsychological task performances were found in the dementia groups. The 2D:4D of healthy women was significantly lower than that of depressed women without AD, i.e., clinical controls, but not significantly different from depressed female patients with AD. This investigation does not support the role of 2D:4D in the development or severity of AD in general, but suggests a potential role of 2D:4D for depression in women. Future studies are warranted to clarify whether 2D:4D can distinguish between early- and late-onset depression in women.
PubMed: 37759830
DOI: 10.3390/brainsci13091229 -
Current Opinion in Chemical Biology Jun 2024Super-resolution microscopy (SRM) has transformed our understanding of proteins' subcellular organization and revealed cellular details down to nanometers, far beyond... (Review)
Review
Super-resolution microscopy (SRM) has transformed our understanding of proteins' subcellular organization and revealed cellular details down to nanometers, far beyond conventional microscopy. While localization precision is independent of the number of fluorophores attached to a biomolecule, labeling density is a decisive factor for resolving complex biological structures. The average distance between adjacent fluorophores should be less than half the desired spatial resolution for optimal clarity. While this was not a major limitation in recent decades, the success of modern microscopy approaching molecular resolution down to the single-digit nanometer range will depend heavily on advancements in fluorescence labeling. This review highlights recent advances and challenges in labeling strategies for SRM, focusing on site-specific labeling technologies. These advancements are crucial for improving SRM precision and expanding our understanding of molecular interactions.
Topics: Proteins; Fluorescent Dyes; Microscopy, Fluorescence; Humans; Staining and Labeling; Animals
PubMed: 38490137
DOI: 10.1016/j.cbpa.2024.102445 -
Cortex; a Journal Devoted To the Study... Feb 2024The processing of numerals as visual objects is supported by an "Inferior Temporal Numeral Area" (ITNA) in the bilateral inferior temporal gyri (ITG). Extant findings...
The processing of numerals as visual objects is supported by an "Inferior Temporal Numeral Area" (ITNA) in the bilateral inferior temporal gyri (ITG). Extant findings suggest some degree of hemispheric asymmetry in how the bilateral ITNAs process numerals. Pollack and Price (2019) reported such a hemispheric asymmetry by which a region in the left ITG was sensitive to digits during a visual search for a digit among letters, and a homologous region in the right ITG that showed greater digit sensitivity in individuals with higher calculation skills. However, the ITG regions were localized with separate analyses without directly contrasting their digit sensitivities and relation to calculation skills. So, the extent of and reasons for these functional asymmetries remain unclear. Here we probe whether the functional and representational properties of the ITNAs are asymmetric by applying both univariate and multivariate region-of-interest analyses to Pollack and Price's (2019) data. Contrary to the implications of the original findings, digit sensitivity did not differ between ITNAs, and digit sensitivity in both left and right ITNAs was associated with calculation skills. Representational similarity analyses revealed that the overall representational geometries of digits in the ITNAs were also correlated, albeit weakly, but the representational contents of the ITNAs were largely inconclusive. Nonetheless, we found a right lateralization in engagement in alphanumeric categorization, and that the right ITNA showed greater discriminability between digits and letters. Greater right lateralization of digit sensitivity and digit discriminability in the left ITNA were also related to higher calculation skills. Our findings thus suggest that the ITNAs may not be functionally identical and should be directly contrasted in future work. Our study also highlights the importance of within-individual comparisons for understanding hemispheric asymmetries, and analyses of individual differences and multivariate features to uncover effects that would otherwise be obscured by averages.
Topics: Humans; Magnetic Resonance Imaging; Functional Laterality; Temporal Lobe; Multivariate Analysis; Individuality; Brain Mapping
PubMed: 37992508
DOI: 10.1016/j.cortex.2023.08.018 -
Cureus Feb 2024Introduction Digital ischemia is alike any other visceral ischemic event leading to severe tissue damage ultimately causing necrosis of the involved extremity. It's like...
Introduction Digital ischemia is alike any other visceral ischemic event leading to severe tissue damage ultimately causing necrosis of the involved extremity. It's like a preview of the upcoming systemic disorder and can present itself in any specialty and hence everyone, be it a physician or a surgeon must be primed toward how to proceed with a case of digital ischemia. In this case series, we present six such cases that presented with digital ischemic events either as a sole presentation or were followed by other systemic manifestations that led to their evaluation and ultimately the etiology behind it. Material and method Patients visiting Rheumatology OPD with complaints suggestive of digital ischemia were included in this study. All patients underwent thorough history taking and clinical examination to establish the cause of digital ischemia. Patients with probable infective, trauma, cardiac, and drug-induced causes and malignancies were excluded. As per probable autoimmune causes, patients underwent evaluation via antinuclear antibodies by immunofluorescence (ANA by IF), antiphospholipid antibodies like lupus anticoagulant (LAC), anticardiolipin antibodies (AcL) and anti Beta2GP1 antibodies, extractable nuclear antigens (ENA) and in cases of suspected vasculitis doppler ultrasound and angiography. Results Six patients were identified as cases primarily presenting with digital ischemia or with a prior history of digital ischemia. Two patients were of the pediatric age group, one 16-year-old male presenting with acute arthritis and a history of digital ischemia one year back, and the other was a 12-year-old female with blackening of the second toe in her left foot with a history of similar complaints in the left great toe for which she underwent amputation of that toe. Other four cases were of the adult age group, with two cases of scleroderma, one with systemic lupus erythematosus, and one with Takayasu arteritis. All of these patients primarily presented to departments other than rheumatology. Conclusion Digital ischemia is a pan-specialty problem with the etiologies spreading across a vast spectrum of rheumatological disorders, many of which may present to different specialties initially, later discovered to be part of the systemic manifestation of autoimmune diseases. Hence, it becomes imperative to have a rheumatological perspective in these cases of digital ischemia which all specialities should be aware of, and timely referral may prevent permanent loss of the digits and in some cases the entire limb.
PubMed: 38558690
DOI: 10.7759/cureus.55133 -
Journal of Neurotrauma Dec 2023Spinal cord injuries (SCI), for which there are limited effective treatments, result in enduring paralysis and hypoesthesia, in part because of the inhibitory...
Recovery of Forearm and Fine Digit Function After Chronic Spinal Cord Injury by Simultaneous Blockade of Inhibitory Matrix Chondroitin Sulfate Proteoglycan Production and the Receptor PTPσ.
Spinal cord injuries (SCI), for which there are limited effective treatments, result in enduring paralysis and hypoesthesia, in part because of the inhibitory microenvironment that develops and limits regeneration/sprouting, especially during chronic stages. Recently, we discovered that targeted enzymatic removal of the inhibitory chondroitin sulfate proteoglycan (CSPG) component of the extracellular and perineuronal net (PNN) matrix via Chondroitinase ABC (ChABC) rapidly restored robust respiratory function to the previously paralyzed hemi-diaphragm after remarkably long times post-injury (up to 1.5 years) following a cervical level 2 lateral hemi-transection. Importantly, ChABC treatment at cervical level 4 in this chronic model also elicited improvements in gross upper arm function. In the present study, we focused on arm and hand function, seeking to highlight and optimize crude as well as fine motor control of the forearm and digits at lengthy chronic stages post-injury. However, instead of using ChABC, we utilized a novel and more clinically relevant systemic combinatorial treatment strategy designed to simultaneously reduce and overcome inhibitory CSPGs. Following a 3-month upper cervical spinal hemi-lesion using adult female Sprague Dawley rats, we show that the combined treatment had a profound effect on functional recovery of the chronically paralyzed forelimb and paw, as well as on precision movements of the digits. The regenerative and immune system related events that we describe deepen our basic understanding of the crucial role of CSPG-mediated inhibition via the PTPσ receptor in constraining functional synaptic plasticity at lengthy time points following SCI, hopefully leading to clinically relevant translational benefits.
Topics: Animals; Female; Rats; Chondroitin ABC Lyase; Chondroitin Sulfate Proteoglycans; Nerve Regeneration; Rats, Sprague-Dawley; Receptor-Like Protein Tyrosine Phosphatases, Class 2; Spinal Cord; Spinal Cord Injuries; Forelimb
PubMed: 37606910
DOI: 10.1089/neu.2023.0117 -
Schizophrenia Bulletin Open Jan 2023Processing speed dysfunction is a core feature of psychosis and predictive of conversion in individuals at clinical high risk (CHR) for psychosis. Although traditionally...
BACKGROUND AND HYPOTHESIS
Processing speed dysfunction is a core feature of psychosis and predictive of conversion in individuals at clinical high risk (CHR) for psychosis. Although traditionally measured with pen-and-paper tasks, computerized digit symbol tasks are needed to meet the increasing demand for remote assessments. Therefore we: (1) assessed the relationship between traditional and computerized processing speed measurements; (2) compared effect sizes of impairment for progressive and persistent subgroups of CHR individuals on these tasks; and (3) explored causes contributing to task performance differences.
STUDY DESIGN
Participants included 92 CHR individuals and 60 healthy controls who completed clinical interviews, the Brief Assessment of Cognition in Schizophrenia Symbol Coding test, the computerized TestMyBrain Digit Symbol Matching Test, a finger-tapping task, and a self-reported motor abilities measure. Correlations, Hedges' g, and linear models were utilized, respectively, to achieve the above aims.
STUDY RESULTS
Task performance was strongly correlated ( = 0.505). A similar degree of impairment was seen between progressive ( = -0.541) and persistent ( = -0.417) groups on the paper version. The computerized task uniquely identified impairment for progressive individuals ( = -477), as the persistent group performed similarly to controls ( = -0.184). Motor abilities were related to the computerized version, but the paper version was more related to symptoms and psychosis risk level.
CONCLUSIONS
The paper symbol coding task measures impairment throughout the CHR state, while the computerized version only identifies impairment in those with worsening symptomatology. These results may be reflective of sensitivity differences, an artifact of existing subgroups, or evidence of mechanistic differences.
PubMed: 37868160
DOI: 10.1093/schizbullopen/sgad027