Biology subjects

Klug, J.

Publications and source records attributed to Klug, J..

8 recordsLinked to original sources

bioRxiv2026

A composite frailty index enables quantification of functional aging and identification of gerotherapeutic drugs in the house cricket.

Frailty, defined by progressive loss of physiological resilience, neuromuscular function, and cognitive capacity, is a central manifestation of biological aging yet remains difficult to quantify in scalable experimental systems. Here, we introduce a Composite Frailty Index (CFI) in the house cricket (Acheta domesticus) that integrates automated measures of locomotion, exploratory behavior, and freezing into a unified, quantitative framework of functional decline. Ten behavioral parameters derived from automated open-field tracking, including locomotor performance, exploratory behavior, and freezing were integrated into the CFI. Locomotor states were classified using k-means clustering (k = 2) of velocity distributions, and all features were normalized to age- or treatment-matched reference populations, discretized into quintiles, and summed to generate a 0-40 frailty score. Aging cohorts (young adult: 4-6 weeks; geriatric: 10-12 weeks, N = 103) and pharmacological cohorts treated at mid-life (8-10 weeks) with rapamycin (14 ppm), acarbose (1000 ppm), or phenylbutyrate (1000 ppm) were evaluated (N = 122). Across chronological aging cohorts, CFI increased from young adults to geriatrics in both females (d = 1.14 [95% CI: 0.53, 1.76], P = 0.0003) and males (d = -1.17 [95% CI: -1.75 to -0.59], P < 0.0001). Using pharmacological intervention cohorts, mid-life rapamycin treatment reduced late-life frailty relative to controls in both females (d = -1.31 [95% CI: -2.09, -0.53], P = 0.0017) and males (d = -1.33 [95% CI: -2.09, -0.58], P = 0.0004), whereas acarbose and phenylbutyrate produced inconclusive effects (ds = -0.54 to -0.03; Ps > 0.05). Together, these findings establish the cricket CFI as a scalable, high-throughput platform for quantifying multidimensional functional aging and prioritizing candidate geroprotective interventions based on clinically relevant endpoints beyond lifespan.

animal behavior and cognition↗

bioRxiv2025

The gerotherapeutic drugs rapamycin, acarbose, and phenylbutyrate extend lifespan and enhance healthy aging in house crickets.

The house cricket (Acheta domesticus) is a promising preclinical geroscience model due to its short lifespan, low maintenance, age-associated functional decline, and responsiveness to geroprotective drugs. Continuous dosing with rapamycin, acarbose, and phenylbutyrate extends lifespan; whether intermittent dosing offers similar benefits remains unknown. We tested 274 sex-matched crickets given 2-week intermittent dosing of each drug starting at mid-age (8-weeks), followed by behavioral testing at 10-weeks (geriatric stage). Assays included Y-maze olfactory discrimination, open-field exploration, and treadmill performance. Locomotor gaits were identified by velocity-based K-means clustering (silhouette > 0.5). A subset was monitored for post-treatment survival using Kaplan-Meier analysis. Olfactory preference was preserved by all drugs (ds = -1.82 to -1.28, Ps < 0.01), with strongest effects in rapamycin-treated individuals. Rapamycin-treated males matched or exceeded juvenile locomotor activity; phenylbutyrate reduced male activity (d = 1.49, P < 0.05) and acarbose increased walking-to-running ratios (d = -0.75, P < 0.05). Rapamycin increased central exploration and freezing (d = -1.55, P < 0.0001), while acarbose and phenylbutyrate increased peripheral freezing (d = -0.76, P < 0.05). Rapamycin and phenylbutyrate extended maximum running time (ds = -2.30 to -1.32, Ps < 0.0001), with sex-specific jumping gains in rapamycin-treated females and acarbose-treated males. Post-treatment lifespan was prolonged by rapamycin (HR = 0.42, P < 0.001) and reduced by acarbose in females (HRs = 2.92 to 3.03, Ps < 0.05). Intermittent rapamycin preserved survival, cognition, and locomotion, while acarbose and phenylbutyrate produced selective benefits, supporting A. domesticus as a scalable model for geroprotective drug discovery.

pharmacology and toxicology↗

bioRxiv2025

Age-related cognitive decline in house crickets reveals conserved patterns of sensory and learning deficits across the lifespan

Cognitive decline with age is characterized by impairments in learning, sensory discrimination, and decision-making. While mammalian models have advanced understanding of the neural substrates of aging, their use in large-scale behavioral studies is limited. Invertebrate models, such as the house cricket (Acheta domesticus), offer short lifespans, high throughput, and conserved neurobiological pathways but remain underexplored in geroscience. We developed a dual behavioral paradigm integrating an olfactory discrimination Y-maze and an escape learning task requiring crickets to override innate odor preferences. Adult, mid-age, and geriatric crickets were tested for sensory discrimination, associative learning, and decision speed. Morphological traits, including antennal and femoral metrics, were quantified to evaluate their influence on cognitive outcomes. Data were analyzed using ANOVA, ANCOVA, and logistic regression models. Aging impaired olfactory preference and learning success, with geriatric crickets showing reduced task acquisition and memory retention. Mid-age individuals exhibited the slowest decision-making, suggesting an early onset shift in behavioral strategy. Morphological traits predicted aspects of sensory performance and physiological resilience, such as reduced weight loss in crickets with larger femoral dimensions but did not explain age-related cognitive deficits. Olfactory decline was particularly pronounced in males, mirroring sex differences observed in human cognitive aging. House crickets exhibit hallmark features of cognitive aging, including sensory decline, learning impairments, and reduced resilience, independent of morphological deterioration. These findings establish the house cricket as a scalable invertebrate model for dissecting conserved mechanisms of neural aging and testing interventions to promote cognitive health.

neuroscience↗

bioRxiv2025

Morphological features of the domestic house cricket (Acheta domesticus) for translational aging studies

Aging alters morphology and locomotor function in diverse organisms, yet standardized model systems for studying these changes remain limited to a relatively few species. Here, we present a comprehensive analysis of age- and sex-dependent morphological variations in house crickets (Acheta domesticus), integrating refined husbandry protocols to enhance reproducibility and translational relevance. We observed progressive increases in body weight, length, and appendage dimensions with age, with pronounced sexual dimorphism emerging post-maturity. Structural adaptations, including increased femoral volume and cross-sectional area, suggest compensatory mechanisms for age-related declines in muscle efficiency, while reduced hind leg-to-body length ratios indicate potential biomechanical constraints on locomotion. Antennal growth patterns highlight prolonged sensory investment, potentially offsetting declining mobility in aging individuals. To ensure data consistency, we implemented a standardized husbandry framework incorporating self-determined photoperiods, co-housing both sexes, and controlled diet and hydration strategies. Our results underscore the necessity of harmonizing environmental conditions in gerontological research, as variations in lighting, substrate availability, and microbiome exposure may significantly impact physiological resilience and behavioral fidelity. Future work should explore the influence of microbiome diversity on lifespan and stress resilience while refining methodologies for cricket rearing from egg to adulthood. By bridging invertebrate and vertebrate aging research, this study positions house crickets as a scalable, high-throughput model for investigating age-related functional decline, behavioral plasticity, and lifespan-extending interventions. Integrating behavioral assays, biomechanical analyses, and molecular markers of aging will further elucidate the interplay between morphology, function, and longevity, advancing the utility of crickets in comparative geroscience.

animal behavior and cognition↗

bioRxiv2024

A drug cocktail of rapamycin, acarbose, and phenylbutyrate enhances resilience to features of early-stage Alzheimer's disease in aging mice

The process of aging is defined by the breakdown of critical maintenance pathways leading to an accumulation of damage and its associated phenotypes. Aging affects many systems and is considered the greatest risk factor for a number of diseases. Therefore, interventions aimed at establishing resilience to aging should delay or prevent the onset of age-related diseases. Recent studies have shown a three-drug cocktail consisting of rapamycin, acarbose, and phenylbutyrate delayed the onset of physical, cognitive, and biological aging phenotypes in old mice. To test the ability of this drug cocktail to impact Alzheimers disease (AD), an adeno-associated-viral vector model of AD was created. Mice were fed the drug cocktail 2 months prior to injection and allowed 3 months for phenotypic development. Cognitive phenotypes were evaluated through a spatial navigation learning task. To quantify neuropathology, immunohistochemistry was performed for AD proteins and pathways of aging. Results suggested the drug cocktail was able to increase resilience to cognitive impairment, inflammation, and AD protein aggregation while enhancing autophagy and synaptic integrity, preferentially in female cohorts. In conclusion, female mice were more susceptible to the development of early stage AD neuropathology and learning impairment, and more responsive to treatment with the drug cocktail in comparison to male mice. Translationally, a model of AD where females are more susceptible would have greater value as women have a greater burden and incidence of disease compared to men. These findings validate past results and provide the rationale for further investigations into enhancing resilience to early-stage AD by enhancing resilience to aging.

pathology↗

bioRxiv2023

A machine learning approach for quantifying age-related histological changes in the mouse kidney.

The ability to quantify aging-related changes in histological samples is important, as it allows for evaluation of interventions intended to effect health span. We used a machine learning architecture that can be trained to detect and quantify these changes in the mouse kidney. Using additional held out data, we show validation of our model, correlation with scores given by pathologists using the Geropathology Research Network aging grading scheme, and its application in providing reproducible and quantifiable age scores for histological samples. Aging quantification also provides the insights into possible changes in image appearance that are independent of specific geropathology-specified lesions. Furthermore, we provide trained classifiers for H&E-stained slides, as well as tutorials on how to use these and how to create additional classifiers for other histological stains and tissues using our architecture.This architecture and combined resources allow for the high throughput quantification of mouse aging studies in general and specifically applicable to kidney tissues.

pathology↗

bioRxiv2021

Short term treatment with a cocktail of rapamycin, acarbose and phenylbutyrate slows aging in mice

Pharmaceutical intervention of aging requires targeting multiple pathways, thus there is rationale to test combinations of drugs each targeting different but overlapping processes. In order to determine if combining drugs previously shown to improve lifespan would have greater impact than any individuyal drug, a diet containing rapamycin at 14 ppm, acarbose at 1000 ppm, and phenylbutyrate at 1000 ppm was fed to 20-month-old C57BL/6 and HET3 4-way cross mice of both sexes for three months. Mice fed the cocktail diet showed a strain and gender-dependent phenotype consistent with healthy aging including decreased body fat and blood glucose, improved cognition, and increased grip strength and walking ability compared to mice fed individual drug or control diets. A cocktail diet containing [1/2] dosing of each compound was overall less effective than the full dose. The composite age-related lesion score of heart, lungs, liver and kidney was decreased in mice fed the cocktail diet compared to mice fed individual drug or control diets suggesting an interactive advantage of the three drugs. Senescence and inflammatory cytokine levels in kidneys from mice fed the cocktail diet were lower than in kidneys from mice fed control diet, and consistent with low expression levels in kidneys from young untreated mice, suggesting the cocktail diet delayed aging partly by senolytic and anti-inflammatory effects.

systems biology↗

bioRxiv2021

Preparing for a second attack: a lesion simulation study on network resilience after stroke

Background and PurposeDoes the brain become more resilient after a first stroke to reduce the consequences of a new lesion? Although recurrent strokes are a major clinical issue, whether and how the brain prepares for a second attack is unknown. This is due to the difficulties to obtain an appropriate dataset of stroke patients with comparable lesions, imaged at the same interval after onset. Furthermore, timing of the recurrent event remains unpredictable. MethodsHere we used a novel clinical lesion simulation approach to test the hypothesis that resilience in brain networks increases during stroke recovery. 16 patients with a lesion restricted to the primary motor cortex were recruited. At 3 time points of the index event (10 days, 3 weeks, 3 months), we mimicked recurrent infarcts by deletion of nodes in brain networks (resting-state fMRI). Graph measures were applied to determine resilience (global efficiency) and wiring cost (mean degree) of the network. ResultsAt 10 days and 3 weeks after stroke, resilience was similar in patients and controls. However, at 3 months, while motor function had fully recovered, resilience to clinically representative simulated lesions was higher compared to controls (cortical lesion p=0.012; subcortical: p=0.009; cortico-subcortical: p=0.009). Similar results were found after random (p=0.012) and targeted (p=0.015) attacks. ConclusionOur results suggest that, after a lesion, brain networks reconfigure to increase resilience to future insults. Lesion simulation is an innovative approach, which may have major implications for stroke therapy. Individualized neuromodulation strategies could be developed to foster resilient network reconfigurations after a first stroke to limit the consequences of future attacks.

neuroscience↗