Age-related Differences Research Articles

Age-related differences in finger interdependence during complex hand movements.

The well-known decrease in finger dexterity during healthy aging leads to a significant reduction in quality of life. Still, the exact patterns of altered finger kinematics of older adults in daily life are fairly unexplored. Finger interdependence is the unintentional co-movement of fingers that are not intended to move, and it is known to vary across the lifespan. Nevertheless, the magnitude and direction of age-related differences in finger interdependence are ambiguous across studies and tasks and have not been explored in the context of daily life finger movements. We investigated five different free and daily-life-inspired finger movements of the right, dominant hand as well as a sequential finger tapping task of the thumb against the other fingers, in 17 younger (22 to 37 years) and 17 older (62 to 80 years) adults using an exoskeleton data glove for data recording. Using inferential statistics, we found that the unintentional co-movement of fingers generally decreases with age in all performed daily-life-inspired movements. Finger tapping, however, showed a trend towards higher finger interdependence for older compared to younger adults. Using machine learning, we predicted the age group of a person from finger interdependence features of single movement trials significantly better than chance level for the daily-life-inspired movements, but not for finger tapping. Taken together, we show that for specific tasks, decreased finger interdependence (i.e., less co-movement) could potentially act as a marker of human aging that specifically characterizes older adults' complex finger movements in daily life.

Cushing's syndrome in the elderly.

Management of Cushing's syndrome (CS) can be particularly challenging in older patients, due to the lack of several clinical features associated with cortisol excess along with a greater burden of comorbidities in them, as compared with the younger. Moreover, interpretation of diagnostic tests could be influenced by age-related physiological changes of cortisol secretion. While mortality is higher and quality of life is more impaired in the elderly with CS as compared with the younger, there is currently no agreement on the most effective therapeutic options in aged individuals, and safety data concerning medical treatment are scanty. In this review, we summarize the current knowledge about age-related differences in etiology, clinical presentation, treatment and outcomes of CS, and describe the potential underlying mechanisms.

Abstract PO4-08-06: Causal Relationships and Familial Aggregation of Mammogram Risk Scores: Insights from Breast Cancer in Twins and Families

Abstract Background: Mammogram risk scores based on texture and density, determined by brightness thresholds, are associated with breast cancer risk differently and could reveal distinct information about breast cancer risk. This study aimed to investigate the causal relationships between these intercorrelated risk scores and the familial aggregation of a texture-based mammogram measure, shedding light on the relevance to breast cancer aetiology. Methods: We analysed data from the Australian Mammographic Density Twins and Sisters Study, including 3195 breast-cancer-free women from 1519 families. The dataset comprised 527 pairs of monozygotic (MZ) twins, 271 pairs of dizygotic (DZ) twins, and 1599 sisters. The average age at mammography for sister pairs ranged from 40 to 70 years. Mammogram risk scores based on texture (named Cirrus) and three density-defined areas (light, bright, and brightest) that were spatially independent were generated. The Inference about Causation from Examination of Familial Confounding (ICE FALCON) method was employed for causal inference. Familial aggregation and the variance of Cirrus were assessed as a function of age using a multivariate normal model for pedigree analysis. The classic twin model was employed but allowing for varying shared environmental effects among different sister pairs. The single-nucleotide polymorphism (SNP)-based heritability was estimated using genetic variants from both closely and distantly related individuals. Model fits were compared using likelihood ratio tests and the Akaike Information Criterion. Results: Causal analysis using ICE FALCON revealed significant positive causal effects, with Cirrus, light areas, and bright areas influencing the brightest areas (accounting for 34%, 55%, and 85% of the associations, respectively). Similarly, light areas and bright areas demonstrated causal effects on Cirrus (accounting for 37% and 28% of the associations, respectively). No age-related differences in familial correlations or Cirrus variance were found for women aged 40 to 70 years. Familial correlations were estimated at 0.51 (0.03) for MZ pairs and 0.16 (0.03) for combined DZ and non-twin sister pairs, with no significant difference between DZ and non-twin sister pairs (P=0.3). Additive genetic effects accounted for up to 32% (5%) of the variance, consistent with SNP-based heritability estimates of 36% (12%). MZ-specific environmental effects contributed to at least 20% (3%), while shared environmental effects for DZ and non-twin sibling pairs accounted for less than 40% of that for MZ pairs. Conclusion: In a mammogram, the lighter (less dense) areas causally influence the brightest (highly dense) areas, including through textural features. These causal relationships provide insights into the relative importance of different mammogram features in breast cancer aetiology. For example, the brightest areas are more aetiologically important for screen-detected breast cancer, while the light areas are more aetiologically important for interval breast cancer. Additionally, specific textural features capture aetiologically independent breast cancer risk information from dense areas. We also confirm the partial heritability of Cirrus, the texture-based mammogram measure, substantially influenced by environmental factors (familial and non-familial). As well as genetic factors, Cirrus could be determined by factors operating at times of life when MZ pairs share their environments to a greater extent than do DZ and non-twin sisters, starting in utero and prior to adulthood, and remaining constant thereafter. These insights from twin and family data enhance our understanding of mammogram risk scores and their implications for breast cancer risk assessment. Citation Format: Zhoufeng Ye, Shuai Li, Gill Dite, Tuong Nguyen, Robert MacInnis, John Hopper. Causal Relationships and Familial Aggregation of Mammogram Risk Scores: Insights from Breast Cancer in Twins and Families [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-08-06.

Biomarkers predicting the effect of anti-TNF treatment in paediatric and adult inflammatory bowel disease.

Paediatric and adult inflammatory bowel disease (pIBD, aIBD) patients may lose response to anti-TNF treatment within the first year. Adult-extrapolated weight-based dosing is incorrect in children, due to age-related pharmacokinetic differences. We investigated biomarkers for initial and maintenance of response to infliximab (IFX) or adalimumab (ADA), comparing pIBD and aIBD patients. In this prospective, observational study, pIBD (n = 24) and aIBD (n = 21) patients were included when initiating anti-TNF. Escalation from standard dosing and continued anti-TNF at 12 and 18 months were assessed. Biomarkers included clinical laboratory parameters, faecal calprotectin (FCP) and IFX trough levels (TLs). Plasma proteomics was performed in pIBD. During our study, treatment escalation (in clinical loss of response) occurred more common in pIBD versus aIBD (p = 0.02). We established that IFX therapy escalation in pIBD patients was not due to low infliximab levels. We identified 9 pro-inflammatory proteins that were elevated in patients losing response. Anti-TNF exposure-response relationship may be different in pIBD versus aIBD. No biomarkers for maintained response were identified, but 9 inflammatory proteins were of interest as potential predictors for loss of response in pIBD.

Abstract PO1-02-14: Breast cancer in older women - long-term prognosis by age and subtype in a large population-based cohort

Abstract Background Compared to middle-aged women, older women have a higher risk of breast cancer death. Whether the increased risk of breast cancer death is present in all subgroups of older adults with breast cancer, or negligible in the subgroups receiving adequate surgical and oncological treatment, has been debated. We studied long-term prognosis by age and subtype, adjusting for stage, treatment, socioeconomic status and comorbidity, clarifying which subgroups of older patients that are at increased risk of breast cancer death. Methods In a nation-wide cohort of 45,949 women aged ≥60 years at diagnosis of breast cancer 1997-2014, we estimated crude probabilities of breast cancer death and from other causes using competing risk methods. Cox proportional hazards models were used to estimate adjusted hazard ratios (HR) with 95% confidence intervals (CI. Results In this large population-based cohort study of older women with breast cancer, we found an increasing risk of breast cancer death with increasing age at diagnosis, both at 5- and 10-year follow up. The strong association between age and breast cancer death was found for all breast cancer subtypes, being most prominent in Her2-positive breast cancer. The age effect was also significant in Luminal A breast cancer where treatment opportunities are not necessarily affected by age. High-risk tumors were equally common in all age groups above 60 years. In multivariable analysis, stage, subtype, grade and treatment were important explanatory variables to the age-related differences in survival, while comorbidity and socioeconomic status contributed minorly. After adjustments, older age remained an independent risk factor for both overall and breast cancer survival. Older women with triple-negative (60-79 years) or Her2-positive (60-84 years) tumors had a 5-year risk of breast cancer death exceeding the risk of death by other causes. Conclusions Older women had a significantly higher risk of breast cancer death irrespective of breast cancer subtype, also in Luminal A disease where treatment opportunities are not necessarily affected by age. Table 3. Crude probabilities of breast cancer specific death and death by other cause (competing cause of death) at 5, 10 and 15 years. Table 4. Multivariable analysis of prognostic factors affecting 15-year overall (OS) and breast cancer- specific survival (BCSS) Table 5. Multivariable analysis of prognostic factors affecting 15-year overall (OS) and breast cancer- specific survival (BCSS) by age at diagnosis and subtype. Citation Format: Amelia Chiorescu, Anna L V Johansson, Antonis Valachis, Alexios Matikas, Jan Frisell, Lars Holmberg, Irma Fredriksson. Breast cancer in older women - long-term prognosis by age and subtype in a large population-based cohort [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-02-14.

Region-specific and age-related differences in astrocytes in the human brain

Astrocyte heterogeneity and its relation to aging in the normal human brain remain poorly understood. We here analyzed astrocytes in gray and white matter brain tissues obtained from donors ranging in age between the neonatal period to over 100 years. We show that astrocytes are differently distributed with higher density in the white matter. This regional difference in cellular density becomes less prominent with age. Additionally, we confirm the presence of morphologically distinct astrocytes, with gray matter astrocytes being morphologically more complex. Notably, gray matter astrocytes morphologically change with age, while white matter astrocytes remain relatively consistent in morphology. Using regional mass spectrometry-based proteomics, we did, however, identify astrocyte specific proteins with regional differences in abundance, reflecting variation in cellular density or expression level. Importantly, the expression of some astrocyte specific proteins region-dependently decreases with age. Taken together, we provide insights into region- and age-related differences in astrocytes in the human brain.

Age-related differences in the association between financial hardship and weight change during the COVID-19 pandemic

ObjectiveTo examine the association of financial hardship with weight changes in the US during the COVID-19 pandemic. MethodsWe used data from the COVID-19's Unequal Racial Burden survey, a nationally representative, cross-sectional, online survey of diverse adults living in the US, 12/2020-2/2021. This study included 1000 Asian, Black, Latino (half Spanish-speaking), and White adults and 500 American Indian or Alaska Native, Native Hawaiian or Pacific Islander, and multiracial adults (5500 total). Age-specific (18–39, 40–59, ≥60) associations between financial hardship domains and weight change were estimated using multinomial logistic regression, adjusted for demographic and health characteristics. ResultsFinancial hardship during the COVID-19 pandemic was prevalent across all age groups (18–39: 76.2 %; 40–59: 75.6 %; ≥60: 50.6 %). Among adults aged 18–39 and ≥ 60 years old, food insecurity was significantly associated with weight loss (18–39: aOR = 1.42, 95 % CI = 1.04, 1.95; ≥60: aOR = 3.67, 95 % CI = 1.50, 8.98). Among all age groups, unmet healthcare expenses was also associated with weight loss (18–39: aOR = 1.31, 95 % CI = 1.01, 1.70; 40–59: aOR = 1.49, 95 % CI = 1.06, 2.08; ≥60: aOR = 1.73, 95 % CI = 1.03, 2.91). Among adults aged 18–39 and ≥ 60 years old, lost income was significantly associated with weight gain (18–39: aOR = 1.36, 95 % CI = 1.09–1.69; ≥60: aOR = 1.46, 95 % CI = 1.04, 2.06), and among adults 40–59 years old, experiencing increased debt was significantly associated with weight gain (aOR = 1.50, 95 % CI = 1.13, 1.99). ConclusionsFor those aged 18–39 and ≥ 60 years old experiencing financial hardship during the COVID-19 pandemic was associated with both weight loss and weight gain. Less correlation was observed among adults aged 40–59.

Age-Related Differences in the Mouse Corneal Epithelial Transcriptome and Their Impact on Corneal Wound Healing.

Aging is a risk factor for dry eye. We sought to identify changes in the aged mouse corneal epithelial transcriptome and determine how age affects corneal sensitivity, re-epithelialization, and barrier reformation after corneal debridement. Corneal epithelium of female C57BL/6J (B6) mice of different ages (2, 12, 18, and 24months) was collected, RNA extracted, and bulk RNA sequencing performed. Cornea sensitivity was measured with an esthesiometer in 2- to 3-month-old, 12- to 13-month-old, 18- to 19-month-old, and 22- to 25-month-old female and male mice. The 2-month-old and 18-month-old female and male mice underwent unilateral corneal debridement using a blunt blade. Wound size and fluorescein staining were visualized and photographed at different time points, and a re-epithelialization rate curve was calculated. There were 157 differentially expressed genes in aged mice compared with young mice. Several pathways downregulated with age control cell migration, proteoglycan synthesis, and collagen trimerization, assembly, biosynthesis, and degradation. Male mice had decreased corneal sensitivity compared with female mice at 12 and 24 months of age. Aged mice, irrespective of sex, had delayed corneal re-epithelialization in the first 48 hours and worse corneal fluorescein staining intensity at day 14 than young mice. Aged corneal epithelium has an altered transcriptome. Aged mice regardless of sex heal more slowly and displayed more signs of corneal epithelial defects after wounding than young mice. These results indicate that aging significantly alters the corneal epithelium and its ability to coordinate healing.

Investigating the Effect of Contextual Cueing with Face Stimuli on Electrophysiological Measures in Younger and Older Adults.

Extracting repeated patterns from our surroundings plays a crucial role in contextualizing information, making predictions and guiding our behavior implicitly. Previous research showed that contextual cueing enhances visual search performance in younger adults. In this study, we investigated whether contextual cueing could also improve older adults' performance and whether age-related differences in the neural processes underlying implicit contextual learning could be detected. Twenty-four younger and 25 older participants performed a visual search task with contextual cueing. Contextual information was generated using repeated face configurations alongside random new configurations. We measured RT difference between new and repeated configurations; ERPs to uncover the neural processes underlying contextual cueing for early (N2pc), intermediate (P3b), and late (r-LRP) processes; and multiscale entropy and spectral power density analyses to examine neural dynamics. Both younger and older adults showed similar contextual cueing benefits in their visual search efficiency at the behavioral level. In addition, they showed similar patterns regarding contextual information processing: Repeated face configurations evoked decreased finer timescale entropy (1-20 msec) and higher frequency band power (13-30 Hz) compared with new configurations. However, we detected age-related differences in ERPs: Younger, but not older adults, had larger N2pc and P3b components for repeated compared with new configurations. These results suggest that contextual cueing remains intact with aging. Although attention- and target-evaluation-related ERPs differed between the age groups, the neural dynamics of contextual learning were preserved with aging, as both age groups increasingly utilized more globally grouped representations for repeated face configurations during the learning process.

Anti_spike and anti_nucleocapsid IgG responses to SARS-CoV-2 in children of Jordan

BackgroundIt is proven that children have significantly milder COVID-19 disease compared to adults. Various immunological characteristics influence this age-related difference in protection against COVID-19. Pediatric COVID-19 in Jordan is extremely under reported. ObjectivesThe primary goal of this work is to identify the anti_S and anti_N antibody responses in a random group of children in Jordan and compare it to that of naturally infected-unvaccinated adults. Methods151 unvaccinated children, 4 days to 18 years old, were screened for anti_S and anti_N antibodies. History of COVID-19 infection or exposure to infection and symptom severity were reported by parents on a special questionnaire. Results78.9 % and 65.3 % of participants were seropositive for anti_S IgG and anti_N Abs, respectively. There was a remarkable association between age and anti_S IgG and anti_N IgG antibody titers, as children aged 12 years or older had increased anti_S IgG titers (mean = 19.3 BAU/mL) compared to younger groups (means of 10.15, 9.24, 7.91 BAU/mL for age groups 6–12, 1–6, less than 1 year, respectively). Gender did not show a statistically important role in anti_S and anti_N IgG seropositivity rates or titers. Children displayed significantly elevated anti_S titers (mean = 13.23 BAU/mL) compared to naturally infected adults (mean = 9.72 BAU/mL), in contrast, adults’ anti_N titers (mean = 39.64 U/mL) were significantly higher compared to those of children (mean = 10.77 U/mL). ConclusionsThe current work provides evidence of distinctly robust and persistent humoral immunity displayed by high anti_S and anti_N IgG in children, even >12 months post-infection. Age was the only factor that had a significant statistical impact on anti_S and anti_N Ab levels among the pediatric group in this study. Children exhibited significantly higher anti_S titers than naturally infected adults. In contrast, adults’ anti_N titers were significantly higher. Such information can assist direct pediatric SARS-CoV-2 immunization programs, with implications for creating age-targeted strategies for diagnostic and population protection measures.

L7 mastered to nativelike proficiency in adulthood – a case study of simultaneous multiple language acquisition processes challenging Lenneberg’s (1967) critical period hypothesis

ABSTRACT This paper seeks to present the case of successful nativelike proficiency in L7, achieved in adulthood. As a case study of multiple language acquisition processes acquired, both in childhood and adulthood, this study operates in the fields of multilingualism and language acquisition. The author presents her experiences of language acquisition and command of the languages: Mauritian Creole Kreol, French, English, Arabic, Urdu, Italian, and Turkish. The paper is shaped into a narrative as it is stipulated that autobiography can be used as data in linguistics research [Pavlenko (2007). Autobiographic narratives as data in applied linguistics. Applied Linguistics, 28(2), 163–188]. Simultaneous acquisition of five languages, in early childhood, is a phenomenon of success in light of Lenneberg’s theory of Critical Period Hypothesis (CPH) (1967). However, Lenneberg’s CPH is challenged when Turkish is analysed as a chronological L7, acquired successfully in adulthood to nativelike proficiency. This is assessed using an eclectic theoretical framework comprising: the theory of Muñoz on the age of learning languages [(2008). Age-related differences in foreign language learning. Revisiting the empirical evidence. IRAL, International Review of Applied Linguistics in Language Teaching, 46(3), 197]; the Dynamic Model of Multilingualism by Philip Herdina and Ulrike Jessner [(2002). A dynamic model of multilingualism: Perspectives of change in psycholinguistics (Vol. 121). Multilingual Matters]; the Factor Model [Hufeisen (2000). A European perspective: Tertiary languages with a focus on German as L3. In J. W. Rosenthal (Ed.), Handbook of undergraduate second language education (pp. 209–229). Routledge], Hammarberg’s [(2017). Becoming multilingual: The macro and the micro time perspective. International Review of Applied Linguistics in Language Teaching, 55(1), 3–22] theory on time perspectives. While justifying the shift of status of Turkish to second language, the author discusses the processes to multilingual success in communicative competence [Hymes (1972) On communicative competence. In J. B. Pride & J. Holmes (Eds.), Sociolinguistics. Selected readings (pp. 269–293). Penguin] in the discussed languages.

Spontaneous recovery from neuromuscular block after a single dose of a muscle relaxant in pediatric patients: A systematic review using a network meta-analytic and meta-regression approach.

Age-related differences in the pharmacokinetics and pharmacodynamics of neuromuscular blocking agents (NMBAs) and the short duration of many surgical procedures put pediatric patients at risk of postoperative residual curarization (PORC). To date, the duration of neuromuscular blocking agent effect in children has not been analyzed in a quantitative review. The current meta-analysis aimed to compare spontaneous recovery following administration of various types and doses of neuromuscular blocking agents and to quantify the effect of prognostic variables associated with the recovery time in pediatric patients. We searched for randomized controlled trials (RCTs) and controlled clinical trials (CCTs) that compared the time to 25% T1 (t25), from 25% to 75% T1 (RI25-75), and to ≥90% train-of-four (tTOF90) neuromuscular recovery between common neuromuscular blocking agent treatments administered as a single bolus to healthy pediatric participants. We compared spontaneous t25, RI25-75, and tTOF90 between (1) neuromuscular blocking agent treatments and (2) age groups receiving a given neuromuscular blocking agent intervention and anesthesia technique. Bayesian random-effects network and pairwise meta-analyses along with meta-regression were used to evaluate the results. We used data from 71 randomized controlled trials/controlled clinical trials including 4319 participants. Network meta-analysis allowed for the juxtaposition and ranking of spontaneous t25, RI25-75, and tTOF90 following common neuromuscular blocking agent interventions. For all neuromuscular blocking agents a log-linear relationship between dose and duration of action was found. With the neuromuscular blocking agent treatments studied, the average tTOF90 (mean[CrI95]) in children (>2-11 y) was 41.96 [14.35, 69.50] and 17.06 [5.99, 28.30] min shorter than in neonates (<28 d) and infants (28 d-12 M), respectively. We found a negative log-linear correlation between age and duration of neuromuscular blocking agent effect. The difference in the tTOF90 (mean[CrI95]) between children and other age groups increased by 21.66 [8.82, 34.53] min with the use of aminosteroid neuromuscular blocking agents and by 24.73 [7.92, 41.43] min with the addition of sevoflurane/isoflurane for anesthesia maintenance. The times to neuromuscular recovery are highly variable. These can decrease significantly with age and are prolonged when volatile anesthetics are administered. This variability, combined with the short duration of many pediatric surgical procedures, makes quantitative neuromuscular monitoring mandatory even after a single dose of neuromuscular blocking agent.

Age-related differences in functional connectivity associated with pain modulation

Growing evidence suggests that aging is associated with impaired endogenous pain modulation, and that this likely underlies the increased transition from acute to chronic pain in older individuals. Resting-state functional connectivity (rsFC) offers a valuable tool to examine the neural mechanisms behind these age-related changes in pain modulation. RsFC studies generally observe decreased within-network connectivity due to aging, but its relevance for pain modulation remains unknown. We compared rsFC within a set of brain regions involved in pain modulation between young and older adults and explored the relationship with the efficacy of distraction from pain. This revealed several age-related increases and decreases in connectivity strength. Importantly, we found a significant association between lower pain relief and decreased strength of three connections in older adults, namely between the periaqueductal gray and right insula, between the anterior cingulate cortex (ACC) and right insula, and between the ACC and left amygdala. These findings suggest that the functional integrity of the pain control system is critical for effective pain modulation, and that its function is compromised by aging.

The time course of encoding specific and gist episodic memory representations among young and older adults.

How rapidly can we encode the specifics versus the gist of episodic memories? Competing theories have opposing answers, but empirical tests are based primarily on tasks of item memory. Few studies have addressed this question with tasks measuring the binding of event components (e.g., a person and a location), which forms the core of episodic memory. None of these prior studies included older adults, whose episodic memories are less specific in nature. We addressed this critical gap by presenting face-scene pairs (e.g., an old man with a park) at various encoding presentation rates to 80 young (M = 21.83 years) and 86 older (M = 68.62 years) adults. Participants completed associative recognition tests featuring old/intact (e.g., the old man with the same park), similar (e.g., the old man with a different park), and unrelated (e.g., the old man with a kitchen) pairs. Multinomial-processing-tree model analyses revealed that young and older adults encoded each pair's gist representation more rapidly than its specific representation, supporting fuzzy-trace theory. No age-related differences in gist representations were obtained at any presentation rate, but older adults required more time to encode specific representations commensurate with those of younger adults. However, older adults' abilities to retrieve these representations were cue-dependent, as they were more susceptible than younger adults to experiencing vivid false memories of similar lures. These phantom recollections were remediated with further increases in encoding time. Thus, slower speed of encoding partially underlies age-related declines in episodic memory specificity, but retrieval mechanisms also play a role. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Investigating age-related differences in muscles of Kazakh horse through transcriptome analysis

This study conducted transcriptome sequencing on the skeletal muscles of three different anatomical locations across various growth stages to investigate the impact of ages on crucial candidate genes and molecular mechanisms associated with muscle development in Kazakh horses. Sixteen Kazakh horses were selected, and they were divided into four age groups, each with four biological replicates. Tissue samples from the longest dorsal muscle, abdominal muscle, and diaphragm muscle were collected for analysis. The results revealed differential mRNA expression in the longest dorsal muscle between the eight-month group (Group O) and the 10-year group (Group F), with 434 up-regulated and 322 down-regulated genes. In the abdominal muscle, there were 125 up-regulated and 127 down-regulated genes, while in the diaphragm muscle, there were 73 up-regulated and 70 down-regulated genes. In this study, GO enrichment analysis focused on biological processes. KEGG pathway analysis highlighted the Oxidative Phosphorylation pathway for the longest dorsal muscle, annotating 37 differentially expressed genes (DEGs), including ATP5PF, NDUFB8, and ATP5MG, all of which were down-regulated. For the abdominal muscle, the ECM-receptor interaction pathway was enriched, annotating 7 DEGs such as COL4A2, COL4A1, and ITGA5. In the diaphragm muscle, the Hippo signaling pathway was enriched, annotating 6 DEGs, including SERPINE1, RASSF1, and FZD10. This study provides robust data support and a theoretical foundation for a comprehensive understanding of the influence of age on skeletal muscle development in horses.

Analysis of age-related changes in the left ventricular myocardium with multiphoton microscopy

Aging induces cardiac remodeling, resulting in an increase in the risk of suffering heart diseases, including heart failure. Collagen deposition increases with age and, together with sarcomeric changes in cardiomyocytes, may lead to ventricular stiffness. Multiphoton (MP) microscopy is a useful technique to visualize and detect variations in cardiac structures in a label free fashion. Here, we propose a method based on MP imaging (both two-photon excitation fluorescence (TPEF) and second harmonic generation (SHG) modalities) to explore and objectively quantify age-related structural differences in various components of cardiac tissues. Results in transmural porcine left ventricle (LV) sections reveal significant differences when comparing samples from young and old animals. Collagen and myosin SHG signals in old specimens are respectively 3.8x and &gt;6-fold larger than in young ones. Differences in TPEF signals from cardiomyocyte were ∼3x. Moreover, the increased amount of collagen in old specimens results in a more organized pattern when compared to young LV tissues. Since changes in collagen and myosin are associated with cardiac dysfunction, the technique used herein might be a useful tool to accurately predict and measure changes associated with age-related myocardium fibrosis, tissue remodeling and sarcomeric alterations, with potential implications in preventing heart disease.

Age-related differences in delay discounting: Income matters.

Although the authors of a recent meta-analysis concluded there were no age-related differences in the discounting of delayed rewards, they did not examine the effects of income (Seaman et al., 2022). Accordingly, the present study compared discounting by younger and older adults (Ages 35-50 and 65-80) differing in household income. Two procedures were used: the Monetary Choice Questionnaire and the Adjusting-Amount procedure. Whereas no age difference was observed between the higher income (> $80,000) age groups, a significant difference was observed between younger and older adults with lower incomes (< $50,000): The younger adults discounted more steeply than the older adults. These findings, which were observed with both discounting procedures, support our buffering hypothesis, which assumes that the scarcity associated with a lower income is a stressor that can lead to steeper discounting, but that age-related increases in emotional stability can buffer such stressors, leading to age-related differences between lower income age groups. In contrast, no age difference was observed in higher income adults who experience much less scarcity. Further support for the buffering hypothesis comes from the finding that there was no age-related difference in discounting by the lower income groups when distress was statistically controlled. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The influence of anterior cingulateGABA+ and glutamateon emotion regulation and reactivity in adolescents and adults.

During adolescence, emotion regulation and reactivity are still developing and are in many ways qualitatively different from adulthood. However, the neurobiological processes underpinning these differences remain poorly understood, including the role of maturing neurotransmitter systems. We combined magnetic resonance spectroscopy in the dorsal anterior cingulate cortex (dACC) and self-reported emotion regulation and reactivity in a sample of typically developed adolescents (n=37; 13-16 years) and adults (n=39; 30-40 years), and found that adolescents had higher levels of glutamate to total creatine (tCr) ratio in the dACC than adults. A glutamate Í age group interaction indicated a differential relation between dACC glutamate levels and emotion regulation in adolescents and adults, and within-group follow-up analyses showed that higher levels of glutamate/tCr were related to worse emotion regulation skills in adolescents. We found no age-group differences in gamma-aminobutyric acid+macromolecules (GABA+) levels; however, emotion reactivity was positively related to GABA+/tCr in the adult group, but not in the adolescent group. The results demonstrate that there are developmental changes in the concentration of glutamate, but not GABA+, within the dACC from adolescence to adulthood, in accordance with previous findings indicating earlier maturation of the GABA-ergic than the glutamatergic system. Functionally, glutamate and GABA+ are positively related to emotion regulation and reactivity, respectively, in the mature brain. In the adolescent brain, however, glutamate is negatively related to emotion regulation, and GABA+ is not related to emotion reactivity. The findings are consistent with synaptic pruning of glutamatergic synapses from adolescence to adulthood and highlight the importance of brain maturational processes underlying age-related differences in emotion processing.

Nonepisodic autobiographical memory details reflect attempts to tell a good story.

A persistent finding in the autobiographical memory (AM) literature is that older adults report more nonepisodic (or generalized/semantic) information than young adults. Since studies are usually focused on memory for episodic (or specific) autobiographical events, the reason for the age difference in nonepisodic AM remains understudied. This experiment investigated whether the higher rate of nonepisodic AM in older adults reflects (a) a difference incommunicative preferences or (b) cognitive decline, by way of either an inhibition deficit or as a means of compensating for a deficit in episodic AM. A sample of 54 young (N = 28, age range = 18-46) and older (N = 26, age range = 62-86) participants retrieved the same AM twice, under two different sets of instructions: to tell a good story for their autobiography, or to provide a detailed police witness statement. Both groups reported more general details when they were aiming to tell a good story. In addition, older adults also reported fewer specific details when the aim was to tell a good story. In a separate ranking task, young and older adults differed in their perceptions of what makes a good story; young adults ranked "detail," "grammar," and "full descriptions" more highly than older adults, whereas older ranked "linking ideas" and "explaining not just describing" more highly than young adults. The results suggest that age-related differences in nonepisodic AM might be explained by communicative preferences rather than cognitive decline. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Difficulty sensitivity replaces reward sensitivity during adolescence: Task-related fMRI and functional connectivity during self-regulative learning choices

AimWe examined age-related differences in valuation and cognitive control circuits during value-based decision-making. Methods13-year-olds (N = 25) and 17-year-olds (N = 22) made a metacognitive choice to be tested or not on an upcoming learning task, based on reward and difficulty associated with word-pairs. To investigate whether these determinants of subjective value are differently processed at different ages, we performed region-of-interest(ROI)-based analyses of task-related and functional connectivity data.Results: We observed age-related differences in responsiveness of valuation structures (amygdala, ventral striatum, ventromedial prefrontal cortex) and caudate nucleus, with activity modulated by reward in 13-year-olds, while in 17-year-olds activity being responsive to difficulty. These accompanied age-related differences in functional connectivity between medial prefrontal and striatal/amygdala seeds. DiscussionThese results are in line with current views that sensitivity changes for reward and difficulty during adolescence are the result of a maturational switch in effort-related signalling in the cognitive control circuit, which increasingly regulates value-signalling structures.