Molecular prevalence, subtype distribution, and zoonotic potential of Blastocystis sp. in wild rodents and shrews inhabiting Zhejiang province of China.

Introduction: Globally, rodents and shrew populations constitute crucial elements of diverse environments and animal communities. It is imperative to study their population dynamics to mitigate any potential negative impact on humans, as they can be involved in the transmission of critical zoonotic agents, such as Blastocystis. Therefore, this study aimed to identify the prevalence and genetic composition of Blastocystis in wild rodents and shrews residing in the Zhejiang provinces of China. Methods: A total of 652 wild rodents and and shrews were captured from three different regions in Zhejiang Province from April 1st to October 31, 2023. The DNA was isolated by collecting fresh feces from the intestines of each rodent or and shrew. Rodent and shrew species were examined by vertebrate cytochrome b (cytb) analysis and PCR amplification. Blastocystis was also found in all fecal samples using PCR analysis and sequencing of the partial small subunit of ribosomal RNA (SSU rRNA) gene. Results: Among all the samples, 6.6% (43/652) showed a positive result for Blastocystis. In the results, 6 species of rodent and shrew were identified with Blastocystis, including Apodemus agrarius (n = 36) (2.8%), Niviventer confucianus (n = 75) (17.3%), Rattus losea (n = 18) (5.6%), R. norvegicus (n = 155) (2.6%), R. tanezumi (n = 86) (3.5%), and Suncus murinus (n = 282) (7.4%). The existence of 6 Blastocystis subtypes, ST4 (n = 33), ST1 (4), ST7 (n = 3), ST2 (n = 1), ST3 (n = 1), and ST5 (n = 1), were confirmed by sequence analysis. Discussion: Based on the molecular data obtained, the wild rodents and shrews under investigation were found to be concurrently infected with zoonotic subtypes of Blastocystis, including ST1 to ST5 and ST7. This suggests that these animals could potentially pose a zoonotic threat to humans and other animals susceptible to Blastocystis infection.

Fetal dystocia in guinea pigs: A case report.

Dystocia is a common complication in guinea pig pregnancies, presenting significant challenges in clinical management. The present case report describes the presentation, diagnosis, and surgical intervention in an 8 months old female guinea pig with dystocia. The subject is a primiparous guinea pig originating from a commercial breeder, exhibited prolonged labor with two pups, one of which was stillborn. Physical examination revealed a distended abdomen, lack of uterine contractions, signs of distress, and vulvar discharge. Radiographic and ultrasound tests confirmed obstruction due to large fetal size and mineralization of the pubic symphysis. Surgical intervention proceeded with a ventral midline approach, ovariohysterectomy and removal of three fetuses. The guinea pig recovered well from the procedure, being discharged with postoperative care, and the use of anti-inflammatory, analgesics, prokinetics, antibiotics as well as scopolamine. The objective of the present work is to discuss and emphasize the importance of veterinary intervention, diagnostic evaluation and therapeutics for the multifactorial nature of dystocia management. Despite the surgical treatment, the prognosis for both dam and offspring remains guarded, highlighting the need for early detection and intervention to optimize outcomes in guinea pig dystocia cases.

A distocia é uma complicação comum em gestações de porquinhas-da-índia, apresentando desafios significativos no manejo clínico. Este relato de caso descreve a apresentação, diagnóstico e intervenção cirúrgica em uma porca-da-índia fêmea de oito meses que estava experimentando distocia. A porquinha-da-índia, primípara e proveniente de um criador comercial, apresentou trabalho de parto prolongado com dois filhotes, um dos quais nasceu natimorto. O exame físico revelou abdome distendido, falta de contrações uterinas, sinais de angústia e secreção vulvar. Exames radiográficos e de ultrassom confirmaram obstrução devido ao tamanho fetal grande e mineralização da sínfise púbica. A intervenção cirúrgica prosseguiu com uma abordagem ventral na linha média, ovariohisterectomia e remoção de três fetos. A paciente se recuperou bem do procedimento e recebeu alta com cuidados pós-operatórios, incluindo o uso de anti-inflamatórios, analgésicos, pró-cinéticos, antibióticos e escopolamina. O objetivo deste trabalho é discutir e destacar a importância da intervenção veterinária, avaliação diagnóstica e terapêutica na natureza multifatorial do manejo da distocia. Apesar do tratamento cirúrgico, o prognóstico tanto para a mãe quanto para a prole permanece reservado, ressaltando a necessidade de detecção e intervenção precoces para otimizar os resultados em casos de distocia em porquinhas-da-índia.

Food Grinding Behavior: A Review of Causality and Influential Factors.

Food waste is a common issue arising from grinding of food by experimental animals, leading to excessive food scraps falling into cages. In the wild, animals grind food by gnawing vegetation and seeds, potentially damaging the ecological environment. However, limited ecology studies have focused on food grinding behavior since the last century, with even fewer on rodent food grinding, particularly recently. Although food grinding's function is partially understood, its biological purposes remain under-investigated and driving factors unclear. This review aims to explain potential causes of animal food grinding, identify influencing factors, and discuss contexts and limitations. Specifically, we emphasize recent progress on gut microbiota significance for food grinding. Moreover, we show abnormal food grinding is determined by degree of excess normal behavior, emphasizing food grinding is not meaningless. Findings from this review promote comprehensive research on the myriad factors, multifaceted roles, and intricate evolution underlying food grinding behavior, benefiting laboratory animal husbandry and ecological environment protection, and identifying potential physiological benefits yet undiscovered.

Estimation of Acceptable Daily Intake Values based on Modeling and In Vivo Mutagenicity of NDSRIs of Fluoxetine, Duloxetine and Atomoxetine.

Nitrosamine drug substance related impurities or NDSRIs can be formed if an active pharmaceutical ingredient (API) has an intrinsic secondary amine that can undergo nitrosation. This is a concern as 1) nitrosamines are potentially highly potent carcinogens, 2) secondary amines in API are common, and 3) NDSRIs that might form from such secondary amines will be of unknown carcinogenic potency. Approaches for evaluating NDSRIs include read across, quantum mechanical modeling of reactivity, in vitro mutation data, and transgenic in vivo mutation data. These approaches were used here to assess NDSRIs that could potentially form from the drugs fluoxetine, duloxetine and atomoxetine. Based on a read across informed by modeling of physicochemical properties and mechanistic activation from quantum mechanical modeling, NDSRIs of fluoxetine, duloxetine, and atomoxetine were 10-100-fold less potent compared with highly potent nitrosamines such as NDMA or NDEA. While the NDSRIs were all confirmed to be mutagenic in vitro (Ames assay) and in vivo (TGR) studies, the latter data indicated that the potency of the mutation response was > 4400 ng/day for all compounds- an order of magnitude higher than published regulatory limits for these NDSRIs. The approaches described herein can be used qualitatively to better categorize NDSRIs with respect to potency and inform whether they are in the ICH M7R2-designated Cohort of Concern.

Maternal immune activation affects female offspring whisker movements during object exploration in a rat model of neurodevelopmental disorders.

Poly I:C rat offspring are used to investigate the effects of in utero exposure to maternal immune activation (MIA) and have been suggested as a model of neurodevelopmental disorders (NDD). The behavioural symptoms of this model are diverse and can vary with external factors, including the choice of background strain and husbandry practices. Measuring whisker movements provides quantitative, robust measurements of sensory, motor and cognitive behaviours in rodents. In this study, whisker movements were investigated in 50-day-old male and female offspring of MIA-exposed rat dams and compared to age-matched offspring of control (vehicle) dams. Rat offspring were filmed using high-speed videography in a sequential object exploration task with smooth and textured objects. Poly I:C treatment effects were found in female offspring that did not increase whisker mean angular position during object exploration, especially for the smooth object, indicating an attentional deficit. Whisker tracking during object exploration is demonstrated here, for the first time, as a useful, quick and non-invasive tool to identify both treatment effects and sex differences in a model of MIA-induced NDDs.

Changes in hippocampal volume, synaptic plasticity and amylin sensitivity in an animal model of type 2 diabetes are associated with increased vulnerability to amyloid-beta in advancing age.

Type-2 diabetes (T2D) is a metabolic disorder that is considered a risk factor for Alzheimer's disease (AD). Cognitive impairment can arise due to hypoglycemia associated with T2D, and hyperamylinemia associated with insulin resistance can enhance AD pathology. We explored whether changes occur in the hippocampus in aging (6-12 months old) female V-Lep○b-/- transgenic (tg) mice, comprising an animal model of T2D. We also investigated whether an increase in vulnerability to Aß (1-42), a known pathological hallmark of AD, is evident. Using magnetic resonance imaging we detected significant decreases in hippocampal brain volume in female tg-mice compared to wild-type (wt) littermates. Long-term potentiation (LTP) was impaired in tg compared to wt mice. Treatment of the hippocampus with Aß (1-42) elicited a stronger debilitation of LTP in tg compared to wt mice. Treatment with an amylin antagonist (AC187) significantly enhanced LTP in wt and tg mice, and rescued LTP in Aß (1-42)-treated tg mice. Taken together our data indicate that a T2D-like state results in an increased vulnerability of the hippocampus to the debilitating effects of Aß (1-42) and that effects are mediated in part by changes in amylin receptor signaling.

Unraveling the Molecular Mechanisms of the Neurodevelopmental Consequences of Fetal Protein Deficiency: Insights From Rodent Models and Public Health Implications.

Fetal brain development requires increased maternal protein intake to ensure that offspring reach their optimal cognitive potential in infancy and adulthood. While protein deficiency remains a prevalent issue in developing countries, it is also reemerging in Western societies due to the growing adoption of plant-based diets, some of which are monotonous and may fail to provide sufficient amino acids crucial for the brain's critical developmental phase. Confounding variables in human nutritional research have impeded our understanding of the precise impact of protein deficiency on fetal neurodevelopment, as well as its implications for childhood neurocognitive performance. Moreover, it remains unclear whether such deficiency could predispose to mental health problems in adulthood, mirroring observations in individuals exposed to prenatal famine. In this review, we sought to evaluate mechanistic data derived from rodent models, placing special emphasis on the involvement of neuroendocrine axes, the influence of sex and timing, epigenetic modifications, and cellular metabolism. Despite notable progress, critical knowledge gaps remain, including understanding the long-term reversibility of effects due to fetal protein restriction and the interplay between genetic predisposition and environmental factors. Enhancing our understanding of the precise mechanisms that connect prenatal nutrition to brain development in future research endeavors can be significantly advanced by integrating multiomics approaches and utilizing additional alternative models such as nonhuman primates. Furthermore, it is crucial to investigate potential interventions aimed at alleviating adverse outcomes. Ultimately, this research has profound implications for guiding public health strategies aimed at raising awareness about the crucial role of optimal maternal nutrition in supporting fetal neurodevelopment.

The Developmental Origins of Health and Disease theory posits that suboptimal conditions during early life exert a profound influence on adult health, potentially predisposing individuals to conditions such as neuropsychiatric disorders. By reviewing studies in rodents, we identified common mechanisms of how inadequate fetal protein uptake alters brain development and may contribute to anxiety, impaired memory function, and altered metabolism in adulthood. Adequate protein consumption during pregnancy is therefore critical to support healthy brain development.

Erythropoietin induces tumour progression and CD39 expression on immune cells in a preclinical model of triple-negative breast cancer.

The adverse effects observed in some cancer patients treated with erythropoiesis-stimulating agents such as erythropoietin (EPO) might be due to the latter's well-known immunosuppressive functions. Here, we used a mouse model of syngeneic triple-negative breast cancer to explore EPO's immunomodulatory role in a tumour setting. Our results showed that EPO treatment promotes tumour growth, exacerbates the 'immune desert', and results in a 'cold tumour'. EPO treatment changed the immune cell distribution in peripheral blood, secondary lymphoid organs, and the tumour microenvironment (TME). Our in-depth analysis showed that EPO mainly impacts CD4 T cells by accelerating their activation in the spleen and thus their subsequent exhaustion in the TME. This process is accompanied by a general elevation of CD39 expression by several immune cells (notably CD4 T cells in the tumour and spleen), which promotes an immunosuppressive TME. Lastly, we identified a highly immunosuppressive CD39+ regulatory T cell population (ICOS+, CTLA4+, Ki67+) as a potential biomarker of the risk of EPO-induced tumour progression. EPO displays pleiotropic immunosuppressive functions and enhances mammary tumour progression in mice.

Host specificity and zoonotic Enterocytozoon bieneusi genotypes in wild rodents from the Inner Mongolian Autonomous Region and Liaoning Province of China.

Introduction: Wild rodents can serve as reservoirs or carriers of E. bieneusi, thereby enabling parasite transmission to domestic animals and humans. This study aimed to investigate the prevalence of E. bieneusi in wild rodents from the Inner Mongolian Autonomous Region and Liaoning Province of China. Moreover, to evaluate the potential for zoonotic transmission at the genotype level, a genetic analysis of the isolates was performed. Methods: A total of 486 wild rodents were captured from two provinces in China. Polymerase chain reaction (PCR) was performed to amplify the vertebrate cytochrome b (cytb) gene in the fecal DNA of the rodents to detect their species. The genotype of E. bieneusi was determined via PCR amplification of the internal transcribed spacer (ITS) region of rDNA. The examination of genetic characteristics and zoonotic potential requires the application of similarity and phylogenetic analysis. Results: The infection rates of E. bieneusi in the four identified rodent species were 5.2% for Apodemus agrarius (n = 89), 4.5% for Cricetulus barabensis (n = 96), 11.3% for Mus musculus (n = 106), and 38.5% for Rattus norvegicus (n = 195). Infection was detected at an average rate of 17.4% among 486 rodents. Of the 11 identified genotypes, nine were known: SHR1 (detected in 32 samples), D (30 samples), EbpA (9 samples), PigEbITS7 (8 samples), HNR-IV (6 samples), Type IV (5 samples), HNR-VII (2 samples), HNH7 (1 sample), and HNPL-V (1 sample). Two novel genotypes were also discovered, NMR-I and NMR-II, each comprising one sample. The genotypes were classified into group 1 and group 13 via phylogenetic analysis. Discussion: Based on the initial report, E. bieneusi is highly prevalent and genetically diverse in wild rodents residing in the respective province and region. This indicates that these animals are crucial for the dissemination of E. bieneusi. Zoonotic E. bieneusi-carrying animals present a significant hazard to local inhabitants. Therefore, it is necessary to increase awareness regarding the dangers presented by these rodents and reduce their population to prevent environmental contamination.

Exploring microtubule dynamics in Alzheimer's disease: Longitudinal assessment using [11C]MPC-6827 PET imaging in rodent models of Alzheimer's-related pathology.

INTRODUCTION: Microtubule (MT) stability is crucial for proper neuronal function. Understanding MT dysregulation is critical for connecting amyloid beta (Aß) and tau-based degenerative events and early changes in presymptomatic Alzheimer's disease (AD). Herein we present positron emission tomography (PET) imaging properties of our MT-PET radiotracer, [11C]MPC-6827, in multiple established AD mouse models. METHODS: Longitudinal PET, biodistribution, autoradiography, immunohistochemistry, and behavioral studies were conducted at multiple time points in APPswe/PSEN1dE9 (APP/PS1), P301S-PS19 (P301S), 5xFAD, and age-matched control mice. RESULTS: Longitudinal [11C]MPC-6827 brain imaging showed significant increases in APP/PS1, P301S, and 5xFAD mice compared to controls. Longitudinal MT-PET correlated positively with biodistribution, autoradiography, and immunohistochemistry results and negatively with behavior data. DISCUSSION: Our study demonstrated significant longitudinal [11C]MPC-6827 PET increases in multiple AD mouse models for the first time. Strong correlations between PET and biomarker data underscored the interplay of MT destabilization, amyloid, and tau pathology in AD. These results suggest [11C]MPC-6827 PET as a promising tool for monitoring MT dysregulation early in AD progression. HIGHLIGHTS: Longitudinal positron emission tomography (PET) imaging studies using [11C]MPC-6827 in multiple established Alzheimer's disease (AD) mouse models revealed an early onset of microtubule dysregulation, with significant changes in brain radiotracer uptake evident from 2 to 4 months of age. Intra-group analysis showed a progressive increase in microtubule dysregulation with increasing AD burden, supported by significant correlations between PET imaging data and biodistribution, autoradiography, and molecular pathological markers. [11C]MPC-6827 PET imaging demonstrated its efficacy in detecting early microtubule alterations preceding observable behavioral changes in AD mouse models, suggesting its potential for early AD imaging. The inclusion of the 5xFAD mouse model further elucidated the impact of amyloid beta (Aß) toxicity on inducing tau hyperphosphorylation-mediated microtubule dysregulation, highlighting the versatility of [11C]MPC-6827 in delineating various aspects of AD pathology. Our study provides immediate clarity on high uptake of the microtubule-based radiotracer in AD brains in a longitudinal setting, which directly informs clinical utility in Aß/tau-based studies.

Ageing-related modification of sleep and breathing in orexin-knockout narcoleptic mice.

Narcolepsy type-1 (NT1) is a lifelong sleep disease, characterised by impairment of the orexinergic system, with a typical onset during adolescence and young adulthood. Since the wake-sleep cycle physiologically changes with ageing, this study aims to compare sleep patterns between orexin-knockout (KO) and wild type (WT) control mice at different ages. Four groups of age-matched female KO and WT mice (16 weeks of age: 8 KO-YO and 9 WT-YO mice; 87 weeks of age: 13 KO-OLD and 12 WT-OLD mice) were implanted with electrodes for discriminating wakefulness, rapid-eye-movement sleep (REMS), and non-REMS (NREMS). Mice were recorded for 48 h in their home cages and for 7 more hours into a plethysmographic chamber to characterise their sleep-breathing pattern. Regardless of orexin deficiency, OLD mice spent less time awake and had fragmentation of this behavioural state showing more bouts of shorter length than YO mice. OLD mice also had more NREMS bouts and less frequent NREMS apneas than YO mice. Regardless of age, KO mice showed cataplexy-like episodes and shorter REMS latency than WT controls and had a faster breathing rate and an increased minute ventilation during REMS. KO mice also had more wakefulness, NREMS and REMS bouts, and a shorter mean length of wakefulness bouts than WT controls. Our experiment indicated that the lack of orexins as well as ageing importantly modulate the sleep and breathing phenotype in mice. The narcoleptic phenotype caused by orexin deficiency in female mice was substantially preserved with ageing.

Cognitive deficits in human ApoE4 knock-in mice: A systematic review and meta-analysis.

Apolipoprotein-E4 (ApoE4) is an important genetic risk factor for Alzheimer's disease. The development of targeted-replacement human ApoE knock-in mice facilitates research into mechanisms by which ApoE4 affects the brain. We performed meta-analyses and meta-regression analyses to examine differences in cognitive performance between ApoE4 and ApoE3 mice. We included 61 studies in which at least one of the following tests was assessed: Morris Water Maze (MWM), novel object location (NL), novel object recognition (NO) and Fear Conditioning (FC) test. ApoE4 vs. ApoE3 mice performed significantly worse on the MWM (several outcomes, 0.17 ≤ g ≤ 0.60), NO (exploration, g=0.33; index, g=0.44) and FC (contextual, g=0.49). ApoE4 vs. ApoE3 differences were not systematically related to sex or age. We conclude that ApoE4 knock-in mice in a non-AD condition show some, but limited cognitive deficits, regardless of sex and age. These effects suggest an intrinsic vulnerability in ApoE4 mice that may become more pronounced under additional brain load, as seen in neurodegenerative diseases.

CRISPR-based genome editing of a diurnal rodent, Nile grass rat (Arvicanthis niloticus).

BACKGROUND: Diurnal and nocturnal mammals have evolved distinct pathways to optimize survival for their chronotype-specific lifestyles. Conventional rodent models, being nocturnal, may not sufficiently recapitulate the biology of diurnal humans in health and disease. Although diurnal rodents are potentially advantageous for translational research, until recently, they have not been genetically tractable. The present study aims to address this major limitation by developing experimental procedures necessary for genome editing in a well-established diurnal rodent model, the Nile grass rat (Arvicanthis niloticus). RESULTS: A superovulation protocol was established, which yielded nearly 30 eggs per female grass rat. Fertilized eggs were cultured in a modified rat 1-cell embryo culture medium (mR1ECM), in which grass rat embryos developed from the 1-cell stage into blastocysts. A CRISPR-based approach was then used for gene editing in vivo and in vitro, targeting Retinoic acid-induced 1 (Rai1), the causal gene for Smith-Magenis Syndrome, a neurodevelopmental disorder. The CRISPR reagents were delivered in vivo by electroporation using an improved Genome-editing via Oviductal Nucleic Acids Delivery (i-GONAD) method. The in vivo approach produced several edited founder grass rats with Rai1 null mutations, which showed stable transmission of the targeted allele to the next generation. CRISPR reagents were also microinjected into 2-cell embryos in vitro. Large deletion of the Rai1 gene was confirmed in 70% of the embryos injected, demonstrating high-efficiency genome editing in vitro. CONCLUSION: We have established a set of methods that enabled the first successful CRISPR-based genome editing in Nile grass rats. The methods developed will guide future genome editing of this and other diurnal rodent species, which will promote greater utility of these models in basic and translational research.

Regrettable Substitutes and the Brain: What Animal Models and Human Studies Tell Us about the Neurodevelopmental Effects of Bisphenol, Per- and Polyfluoroalkyl Substances, and Phthalate Replacements.

In recent decades, emerging evidence has identified endocrine and neurologic health concerns related to exposure to endocrine-disrupting chemicals (EDCs), including bisphenol A (BPA), certain per- and polyfluoroalkyl compounds (PFASs), and phthalates. This has resulted in consumer pressure to remove these chemicals from the market, especially in food-contact materials and personal care products, driving their replacement with structurally or functionally similar substitutes. However, these "new-generation" chemicals may be just as or more harmful than their predecessors and some have not received adequate testing. This review discusses the research on early-life exposures to new-generation bisphenols, PFASs, and phthalates and their links to neurodevelopmental and behavioral alterations in zebrafish, rodents, and humans. As a whole, the evidence suggests that BPA alternatives, especially BPAF, and newer PFASs, such as GenX, can have significant effects on neurodevelopment. The need for further research, especially regarding phthalate replacements and bio-based alternatives, is briefly discussed.

Development of neuronal timescales in human cortical organoids and rat hippocampus dissociated cultures.

To support complex cognition, neuronal circuits must integrate information across multiple temporal scales, ranging from milliseconds to decades. Neuronal timescales describe the duration over which activity within a network persists, posing a putative explanatory mechanism for how information might be integrated over multiple temporal scales. Little is known about how timescales develop in human neural circuits or other model systems, limiting insight into how the functional dynamics necessary for cognition emerge. In our work, we show that neuronal timescales develop in a non-linear fashion in both human cortical organoids and dissociated rat hippocampus cultures. We use spectral parameterization of spiking activity to extract an estimate of neuronal timescale that is unbiased by co-evolving oscillations. Cortical organoid timescales begin to increase around month 6 post-differentiation. We complement these findings with an analysis of timescales in rodent hippocampal dissociated cultures over development and see that timescales decrease from in vitro days 13-23 before stabilizing. We speculate that cortical organoid development over the duration studied here reflects an earlier stage of a generalized developmental timeline in contrast to the rodent hippocampal cultures, potentially accounting for differences in timescale developmental trajectories. The fluctuation of timescales might be an important developmental feature that reflects the changing complexity and information capacity in developing neuronal circuits.

Evaluating climate-dependent distribution of orthohantaviruses with monitoring wild rodents: One Health Perspective†.

Orthohantaviruses, cause hemorrhagic fever with renal syndrome, nephropathia epidemica, and hantavirus pulmonary syndrome, are major public health problems all over the world. Wild rodent surveillance for orthohantaviruses is of great importance for the preparedness against these human infections and the prediction of possible outbreak regions. Thus, we aimed to screen orthohantaviruses in wild rodents in Southern Anatolia, where the area has some of the glacial period refugia in the Mediterranean Basin, and interpret their current epidemiology with climatic biovariables in comparison with previously positive regions.We trapped muroid rodents between 2015 and 2017, and screened for orthohantaviruses. Then, we evaluated the relationship between orthohantavirus infections and bioclimatic variables. In spite of the long-term and seasonal sampling, we found no evidence for Orthohantavirus infections. The probable absence of orthohantaviruses in the sampling area was further evaluated from the climatic perspective, and results led us suggest that Orthohantavirus epidemiology might be relatively dependent on precipitation levels in driest and warmest quarters, and temperature fluctuations.These initial data might provide necessary perspective on wild rodent surveillance for orthohantaviruses in other regions, and help to collect lacking data for a such habitat suitability study in a bigger scale in the future.

Stereotaxic Surgery as a Method to Deliver Epigenetic Editing Constructs in Rodent Brain.

Modern neuroscience research is increasingly discovering that alterations in epigenetic states within key brain cells is correlated with brain diseases. These epigenetic alterations may include changes in histone post-translational modifications and/or DNA modifications, all of which affect transcription and other gene expression programs within the brain cells that comprise central brain regions. However, the exact causal contribution of these epigenome changes to brain disease cannot be elucidated in the absence of direct in vivo manipulations in the implicated brain areas. Combining the design and creation of epigenetic editing constructs, gene delivery strategies, and stereotaxic surgery enables neuroscience researchers to target and manipulate the epigenetic state of the brain cells of laboratory rodents in a locus-specific manner and test its causal contribution to disease-related pathology and behaviors. Here, we describe the surgical protocol utilized by our group and others, which is optimized for herpes simplex virus delivery into the mouse brain, although the protocol outlined herein could be applied for delivery of adeno-associated viruses, lentiviruses, or nonviral gene-delivery methods in both mice and rats. The method allows for the overexpression of engineered DNA-binding proteins for direct and targeted epigenome editing in rodent brain with excellent spatiotemporal control. Nearly any brain region of interest can be targeted in rodents at every stage of postnatal life. Owing to the versatility, reproducibility, and utility of this technique, it is an important method for any laboratory interested in studying the cellular, circuit, and behavioral consequences of manipulating the brain epigenome in laboratory rodents.

Coexistence of roof rats and carnivores in barns on a livestock farm in Japan.

Brown rats (Rattus norvegicus), roof rats (Rattus rattus), and house mice (Mus musculus) are considered to be important pests on livestock farms. Although the diel activity patterns of rodents are key to their control, information on this aspect of their ecology is limited. Furthermore, the effect of carnivores on rodent activity patterns as well as the carnivore species present on livestock farms is unclear. Here, we set camera traps in an open-type cow barn and in an enclosed pig barn on the same livestock farm in Japan from August through October 2021. The only rodents observed in both barns were roof rats, and the carnivore species observed were dogs (Canis familiaris), cats (Felis catus), and Japanese weasels (Mustela itatsi). Roof rats showed different patterns of activity and behavior between the barns. However, because the pattern in both barns was nocturnal, the activity patterns of roof rats and carnivores showed a moderate to high degree of overlap. Therefore, roof rats did not appear to shift their activity patterns to avoid nocturnal carnivores. Taken together, the present study provides valuable information for rodent control on livestock farms in Japan.

Assessing human carcinogenicity risk of agrochemicals without the rodent cancer bioassay.

The rodent cancer bioassays are conducted for agrochemical safety assessment yet they often do not inform regulatory decision-making. As part of a collaborative effort, the Rethinking Carcinogenicity Assessment for Agrochemicals Project (ReCAAP) developed a reporting framework to guide a weight of evidence (WOE)-based carcinogenicity assessment that demonstrates how to fulfill the regulatory requirements for chronic risk estimation without the need to conduct lifetime rodent bioassays. The framework is the result of a multi-stakeholder collaboration that worked through an iterative process of writing case studies (in the form of waivers), technical peer reviews of waivers, and an incorporation of key learnings back into the framework to be tested in subsequent case study development. The example waivers used to develop the framework were written retrospectively for registered agrochemical active substances for which the necessary data and information could be obtained through risk assessment documents or data evaluation records from the US EPA. This exercise was critical to the development of a framework, but it lacked authenticity in that the stakeholders reviewing the waiver already knew the outcome of the rodent cancer bioassay(s). Syngenta expanded the evaluation of the ReCAAP reporting framework by writing waivers for three prospective case studies for new active substances where the data packages had not yet been submitted for registration. The prospective waivers followed the established framework considering ADME, potential exposure, subchronic toxicity, genotoxicity, immunosuppression, hormone perturbation, mode of action (MOA), and all relevant information available for read-across using a WOE assessment. The point of departure was estimated from the available data, excluding the cancer bioassay results, with a proposed use for the chronic dietary risk assessment. The read-across assessments compared data from reliable registered chemical analogues to strengthen the prediction of chronic toxicity and/or tumorigenic potential. The prospective case studies represent a range of scenarios, from a new molecule in a well-established chemical class with a known MOA to a molecule with a new pesticidal MOA (pMOA) and limited read-across to related molecules. This effort represents an important step in establishing criteria for a WOE-based carcinogenicity assessment without the rodent cancer bioassay(s) while ensuring a health protective chronic dietary risk assessment.

Effect of Rodent Control Program on Incidence of Zoonotic Cutaneous Leishmaniasis, Iran.

We report the effect of a rodent control program on the incidence of zoonotic cutaneous leishmaniasis in an endemic region of Iran. A 1-year interruption in rodent control led to 2 years of increased incidence of zoonotic cutaneous leishmaniasis. Restarting rodent control led to a decline of zoonotic cutaneous leishmaniasis.