Development Of Abnormal Behavior Research Articles

126 Time-budget and welfare indicators of stabled horses in three different stall architectures: A cross-sectional study

Keeping horses in single stalls can prevent them from performing natural behaviors leading to the development of abnormal behaviors (AB) and stereotypic behaviors (SB). Time-budget (TB) is the daily amount of time an animal engages in behavioral activities. Differences in the TB of domesticated horses compared with feral conspecifics in their natural environment can be used to reveal welfare impairment. Other measurements indicative of stress levels in horses are the cortisol circadian rhythm (CCR), and the leucocyte numbers (LN). The current study aimed to identify how 3 different stall architectures can influence the TB and physiological parameters in full-time stabled horses fed at 1.45% DMI/BW twice a day with a 34:66 grain: forage ratio. Stall types included: 1) 3.2 × 3.7m stalls with tactile contact (TC) between horses, B1; 2) 2.6 × 3.5m stalls with only visual contact (VC) between horses with outside view, B2; 3) 2.3 × 3.4m stalls with VC and outside view, B3. The horses were used for light exercise, 4 d a week. Surveillance cameras were installed in one stall per barn. Twenty-nine mixed breed horses (10 horses from B1 and B3, and 9 from B2) were randomly selected and filmed for one period of 24 h per horse. The video was analyzed with continuous sampling and the time spent in SB, AB and other activities was measured second-by-second and inserted into a spreadsheet. Blood collection wasperformed one day after de recording period at 8:00 a.m. and at 5:00 p.m. The samples were used to determine the cortisol levels, and CCR. The effects of the different stall architectures were analyzed by ANOVA and significant results compared by post hoc Tukey test. B1 had higher social interaction time (2.77% of the TB) compared with B2 (0%) and B3 (0.01%) (P = 0.020), with no other differences among barns. Restricted availability of food had a direct impact on all the horses’ TB, creating long periods of idleness (41% of the TB observing the exterior, 18% of the TB standing attentively) and fasting. The low time spent eating (204 ± 13 min) may have led horses to develop AB like bed-eating (176 ± 19 min), coprophagy (18 ± 9 min) and wood-chewing (42 ± 19 min). All horses presented SB and AB, 25% of the horses low LN, 38% of the horses had cortisol above the reference range, and 29% of the horses an altered CCR. The physiological and TB alterations along with high prevalence of SB and AB indicate that horses were in a state of chronic stress and the stalls’ architecture did not affect the horses’ capability to cope with such housing conditions. Feed restriction likely led to AB and SB.

Malfunctioned inflammatory response and serotonin metabolism at the microbiota-gut-brain axis drive feather pecking behavior in laying hens

Feather pecking (FP) is a multifactorial abnormal behavior in laying hens where they display harmful pecks in conspecifics. FP has been associated with the altered functioning of the microbiome-gut-brain axis affecting host emotions and social behavior. The altered levels of serotonin (5-HT), a key monoaminergic neurotransmitter at both terminals of the gut-brain axis, affect the development of abnormal behavior, such as FP in laying hens. However, the underlying mechanism involving reciprocal interactions along the microbiota-gut-brain axis, particularly about the metabolism of 5-HT, remains unclear in FP phenotypes. This study examined the microbiota diversity, intestinal microbial metabolites, inflammatory responses, and 5-HT metabolism in divergently selected high (HFP; n=8) and low (LFP; n=8) FP hens to investigate the possible interconnections between FP behavior and the examined parameters. The 16S rRNA analysis revealed that compared to LFP birds, the gut microbiota of HFP birds exhibited a decrease in the abundance of phylum Firmicutes and genera Lactobacillus, while an increase in the abundance of phylum Proteobacteria and genera Escherichia Shigella and Desulfovibrio. Furthermore, the intestinal differential metabolites associated with FP phenotypes were mainly enriched in the tryptophan metabolic pathway. HFP birds had higher tryptophan metabolites and possibly a more responsive immune system compared to the LFP birds. This was indirectly supported by altered TNF-α levels in the serum and expression of inflammatory factor in the gut and brain. Moreover, HFP birds had lower serum levels of tryptophan and 5-HT compared to LFP birds, which was consistent with the downregulation of 5-HT metabolism-related genes in the brain of HFP birds. The correlation analysis revealed that genera Lactobacillus and Desulfovibrio were associated with differences in intestinal metabolites, 5-HT metabolism, and inflammatory response between the LFP and HFP birds. In conclusion, differences in the cecal microbiota profile, immune response and 5-HT metabolism drive FP phenotypes, which could be associated with the gut abundance of genera Lactobacillus and Desulfovibrio.

Adolescent microglia stimulation produces long-lasting protection against chronic stress-induced behavioral abnormalities in adult male mice

Our previous studies had reported that microglia activation one day before stress exposure prevented the behavioral abnormalities induced by chronic stress in adult mice, and a 10-day interval between microglia stimulation and stress exposure can abolish the prophylactic effect of LPS preinjection on the behavioral abnormalities induced by chronic stress, which, however, could be rescued by repeated LPS injection. This suggests that increased stimulation of microglia results in animals developing a strong ability to prevent deleterious stress stimuli. Because microglia in the adolescent brain exhibit flexible immunological plasticity, we hypothesize that a single low-dose LPS injection during adolescence may provide long-lasting protection against behavioral abnormalities induced by chronic stress in adult mice. As expected, our results showed that a single injection of LPS (100 μg/kg) at post-natal day 28 (PND 28) prevented the development of abnormal behaviors and shifted neuroinflammatory responses toward an anti-inflammatory phenotype in adult mice treated with CSDS at their different stages of the age (PND 56, 140, and 252). Moreover, pretreatment with minocycline or PLX3397 to inhibit microglial activation abolished the prophylactic effect of LPS preinjection after PND 28 on behavioral abnormalities and neuroinflammatory responses induced by CSDS in adult mice at their different stages of the age, PND 56, 140, and 252. These results indicate that stimulation of microglia in adolescence may confer long-lasting protection against neuroinflammatory responses and behavioral abnormalities induced by chronic stress in adult mice. This may offer the potential for the development of a “vaccine-like strategy” to prevent mental disorders.

The effect of age on discrimination learning and self-control in a marshmallow test for pigs

Both humans and nonhuman animals need to show self-control and wait for a larger or better reward instead of a smaller or less preferred but instant reward on an everyday basis. We investigated whether this ability undergoes ontogenetic development in domestic pigs (similar to what is known in human infants) by testing if and for how long nine- and 16-week-old pigs wait for a larger amount of their preferred reward. In a delay-of-gratification task, animals first learned that a small reward was hidden under a white cup and a large reward under a black cup, and then the delay to deliver the large reward was gradually increased. The results show that older pigs could wait longer for a larger reward than younger pigs (10.6 ± 1.3 s vs. 5.2 ± 1.5 s), thereby confirming our hypothesis of ontogenetic development of self-control in pigs. This self-control is likely to be regulated by the behavioural inhibition system and associated systems. Self-control or, more specifically the lack of it may be involved in the development of abnormal behaviours, not only in humans but also in animals. Therefore, research on self-control in decision-making might provide a new perspective on abnormal behaviours in captive animals.

Factors in children with a history of neonatal abstinence syndrome at 10 years of age: Evidence from the maternal lifestyle study.

Few studies have addressed the impact of prior prenatal substance exposure and current household environment on neurodevelopmental health in children with a history of neonatal abstinence syndrome (NAS). This study aimed to describe the prenatal exposures, household environment, and neurodevelopmental health at 10 years of age among children with a history of NAS. This study was a retrospective, descriptive design using data from the Maternal Lifestyle Study. Descriptive analyses were conducted. A total of 234 children with a history of NAS were included in this study. Variables selected based on the socio-ecological model included prenatal exposures, household environment, and neurodevelopmental health outcomes. In this sample, most children were male (63%) with prenatal polysubstance exposure (80%). The majority lived in a home where substance use occurred (68%). Children experienced abnormal cognitive development (26%), language disorders (24%), learning disorders (23%), and abnormal behavioral development (16%). This study extends the description of children with a history of NAS beyond 5 years of age. Pediatric nurses can ensure that children with a history of NAS receive neurodevelopmental screening up to and beyond 10 years of age.

Factors Associated With the Development and Prevalence of Abnormal Behaviors in Horses: Systematic Review With Meta-Analysis

Researchers believe that the development and prevalence of abnormal behaviors in horses may be caused by several environmental and biological factors, and the literature offers numerous reports that discuss the causes and effects of stereotypies in these animals. In this light, this study aimed to conduct a systematic review and meta-analysis of the scientific literature, summarizing the main risk factors associated with the development of abnormal behaviors in horses. The searches were conducted over the course of four years in Portuguese, Spanish, and English. The publications reviewed were full text research thesis or articles that addressed issues within the following criteria: (1) presentation of epidemiological information on the studied population; (2) prevalence of abnormal behaviors in equine populations; (3) factors associated with the development or prevalence of stereotypies. Data were extracted from each study and inserted into an Excel spreadsheet to be analyzed through descriptive statistics. In addition, the Mann-Whitney U test was used to verify the existence of significant differences between the methodologies (direct observation/questionnaires). The dataset was also analyzed through data mining to identify the main factors that influence the prevalence of abnormal behaviors in the studied population. The results showed a great variation in the mean prevalence of abnormal behaviors, with no significant difference between research conducted through questionnaires or direct observation, and the data mining technique identified that incorrect nutritional management may be the main factor influencing the development and prevalence of abnormal behaviors in horses.

Basic Needs in Horses?-A Literature Review.

Simple SummaryAll animals have requirements that are essential for their welfare, and when these basic needs are not met, the animal suffers. In horses, it is claimed that these needs include social contact, social companionship, free movement and access to roughage in the form of grass, hay and/or straw. To validate this claim, this review examines 38 studies that reported on horses’ responses when one or more of these factors are restricted. We categorised the type of responses investigated: (a) Stress (e.g., increased stress hormones), (b) Active (e.g., increased aggression), (c) Passive (e.g., depressive-like behaviour) and (d) Abnormal Behaviour (e.g., stereotypies), and analysed the frequencies with which the investigated responses were shown. Overall, the studies reported that horses did react to restrictions in the described basic needs, especially to combinations of restricted social contact, free movement and access to roughage. The observation of passive responses and the development of abnormal behaviour provided compelling evidence that horses were suffering under these restrictions, and existing abnormal behaviours indicated that they had suffered at some time in the past. We conclude that the literature supports the claim that social contact, free movement and access to roughage are basic needs in horses and need to be taken into consideration to ensure their mental and physical welfare in management and training.Every animal species has particular environmental requirements that are essential for its welfare, and when these so-called “basic needs” are not fulfilled, the animals suffer. The basic needs of horses have been claimed to be social contact, social companionship, free movement and access to roughage. To assess whether horses suffer when one or more of the four proposed basic needs are restricted, we examined several studies (n = 38) that reported behavioural and physiological reactions to these restrictions. We assigned the studies according to the four types of responses investigated: (a) Stress, (b) Active, (c) Passive, and (d) Abnormal Behaviour. Furthermore, the number of studies indicating that horses reacted to the restrictions were compared with the number of studies reporting no reaction. The limited number of studies available on single management restrictions did not allow conclusions to be drawn on the effect of each restriction separately, especially in the case of social companionship. However, when combinations of social contact, free movement and access to roughage were restricted, many of the horses had developed responses consistent with suffering. Passive Responses, indicating acute suffering, and Abnormal Behaviour, indicating suffering currently or at some time in the past, were especially clearly demonstrated. This provides further evidence of the usefulness of assessing behavioural parameters in combination with physiological measurements when evaluating horse welfare. This meta-analysis of the literature confirms that it is justified to claim that social contact, free movement and access to roughage are basic needs in horses.

A novel murine model to study the impact of maternal depression and antidepressant treatment on biobehavioral functions in the offspring

Antenatal psychopathology negatively affects obstetric outcomes and exerts long-term consequences on the offspring’s wellbeing and mental health. However, the precise mechanisms underlying these associations remain largely unknown. Here, we present a novel model system in mice that allows for experimental investigations into the effects of antenatal depression-like psychopathology and for evaluating the influence of maternal pharmacological treatments on long-term outcomes in the offspring. This model system in based on rearing nulliparous female mice in social isolation prior to mating, leading to a depressive-like state that is initiated before and continued throughout pregnancy. Using this model, we show that the maternal depressive-like state induced by social isolation can be partially rescued by chronic treatment with the selective serotonin reuptake inhibitor, fluoxetine (FLX). Moreover, we identify numerous and partly sex-dependent behavioral and molecular abnormalities, including increased anxiety-like behavior, cognitive impairments and alterations of the amygdalar transcriptome, in offspring born to socially isolated mothers relative to offspring born to mothers that were maintained in social groups prior to conception. We also found that maternal FLX treatment was effective in preventing some of the behavioral and molecular abnormalities emerging in offspring born to socially isolated mothers. Taken together, our findings suggest that the presence of a depressive-like state during preconception and pregnancy has sex-dependent consequences on brain and behavioral functions in the offspring. At the same time, our study highlights that FLX treatment in dams with a depression-like state can prevent abnormal behavioral development in the offspring.

Validation of the Greek version of the Problematic Internet Use Questionnaire - Short Form (PIUQ-SF-6)

Internet is a necessary tool of everyday routine, however, concerns about the development of abnormal behaviours in relation to its use by adolescents are constantly growing. The need of brief screening tools for problematic internet use in teenagers in Greece is imperative. The purpose of this study was to validate the 6-item short form of the Problematic Internet Use Questionnaire (PIUQ-SF-6) in a Greek sample of adolescents. The sample consisted of 200 adolescents (55.0% males, 61.6% high school students, 38.4% junior high school students) who completed the study’s questionnaires i.e., a demographic questionnaire, the PIUQ-SF-6, the Young’s Diagnostic Questionnaire (YDQ) and the Adolescent Computer Addiction Test (ACAT). The internal consistency of the Greek version of PIUQ-SF-6 was sufficient and acceptable (Cronbach’s alpha coefficient a = 0.80). Confirmatory Factor Analysis was significant, and goodness-of-fit was adequate. For establishing convergent validity, Pearson’s and Spearman’s correlation coefficients were calculated between the PIUQ-SF-6 and ACAT scales and Receiver Operating Characteristic (ROC) analysis (between PIUQ-SF-6 and YDQ) indicated an excellent accuracy. The Greek version of the PIUQ-SF-6 demonstrated satisfactory psychometric properties (reliability and validity) and is recommended as a reliable screening tool for problematic internet use in Greek adolescents.

Influence of environmental enrichment on the behavior of captive Ateles paniscus (Primates: Atelidae) in the Parque Zoobotânico Getúlio Vargas, Salvador, Bahia, Brazil

Técnicas de enriquecimento ambiental tornam o ambiente cativo mais interessante e agradável para os animais, aumentando o bem-estar e prevenindo o desenvolvimento de comportamentos anormais. Nesta pesquisa, avaliamos a influência de diferentes técnicas de enriquecimento no comportamento de dois indivíduos de Ateles paniscus mantidos cativos no Parque Zoobotânico Getúlio Vargas, Salvador, Brasil. O estudo foi dividido em cinco fases: controle; enriquecimento sensorial; enriquecimento social; enriquecimento alimentar e pós-enriquecimento. O método animal-focal com registro instantâneo foi utilizado para registrar os atos comportamentais exibidos nas diferentes fases de enriquecimento e estes foram comparados, quanto à sua frequência, com os exibidos na fase controle. Também foi comparada a frequência de uso dos artefatos introduzidos no recinto durante as fases sensorial e alimentar. De modo geral, não houve diferenças entre os atos comportamentais exibidos nas diferentes fases de enriquecimento, exceto durante a fase de enriquecimento alimentar do macho. Também não houve diferenças quanto ao uso dos artefatos. Contudo, os resultados evidenciam a influência de um ambiente enriquecido sobre a frequência de ocorrência dos comportamentos dos indivíduos. É possível que as condições do recinto e a presença dos visitantes exerçam influências negativas no comportamento dos indivíduos, de modo a não favorecer a redução efetiva dos comportamentos anormais observado.

Effects of access to stationary brushes and chopped hay on behavior and performance of individually housed dairy calves

Providing individually housed dairy calves with opportunities for a greater range of natural behaviors, including foraging and grooming, has broad benefits for their behavioral development and performance. We evaluated the effects of providing hay and stationary brushes on performance and time engaged in feeding, grooming, and nonnutritive oral behaviors. Holstein calves were individually housed and assigned at 14 d of age to 1 of 4 treatments providing: a stationary brush (n = 10), chopped coastal bermudagrass hay (n = 9), both a stationary brush and chopped bermudagrass (n = 10), or no brushes nor additional feed (n = 10). Calves had ad libitum access to calf starter and water and were provided 8 L/d pasteurized waste milk fed in 2 meals via a teat bucket. Beginning at 43 d of age, calves were weaned across 10 d. Solid feed intake was measured daily, and growth parameters and cleanliness were measured weekly. Behavioral data were collected on 2 consecutive days at 25 ± 3 d, recorded continuously from video within daylight for 12 h. Provision of hay tended to increase solid feed intake and average daily gain during weaning, and calves provided a brush had improved coat cleanliness during weaning. Calves performed nonnutritive oral behavior, primarily directed toward the pen, with peaks in these abnormal behaviors around milk feeding. The duration of teat-directed nonnutritive sucking was reduced by access to either hay or a brush, compared with neither (3.2 vs. 6.8 min/12 h observation). Provision of a brush reduced pen-directed sucking (38.4 vs. 59.0 min/12 h observation), particularly at milk-feeding time, and also reduced standing time around milk feeding. Self-grooming was not affected by brush or hay access, but provision of the brush increased total time engaged in grooming behaviors (52.9 vs. 40.2 min/12 h observation). These results support benefits of accommodating natural foraging and grooming behaviors, yet reveal a high prevalence of nonnutritive oral behaviors in dairy calves. Overall, these findings underline the importance of environmental complexity in early rearing environments, and compel further consideration of behavioral needs of dairy calves to reduce the development of abnormal behaviors.

Comparison of Behavior and Genetic Structure in Populations of Family and Kenneled Beagles.

In dogs, the social and spatial restriction associated with living in a kennel environment could lead to chronic stress and the development of abnormal behaviors (“kennel-dog syndrome”). However, little is known about how kenneled dogs differ from their conspecifics living as pets in human families. In the current study, using a test battery exposing the dogs to novel stimuli, we compared the behavior of three groups of beagles: (1) kenneled dogs living in a restricted environment with limited human contact (N = 78), (2) family dogs living in human families as pets (N = 37), and (3) adopted dogs born in the kenneled population but raised in human families (N = 13). We found one factor comprising most of the test behaviors, labeled as Responsiveness. Family dogs and adopted dogs scored higher in Responsiveness than kenneled dogs. However, 23% of the kenneled dogs were comparable to family and adopted dogs based on a cluster analysis, indicating a similar (positive) reaction to novel stimuli, while 77% of the kenneled dogs were unresponsive (mostly immobile) in at least part of the test. To assess if the behavioral difference between the family and kenneled dogs could be due to genetic divergence of these two populations and/or to lower genetic diversity of the kenneled dogs, we analyzed their genetic structure using 11 microsatellite markers. We found no significant difference between the populations in their genetic diversity (i.e., heterozygosity, level of inbreeding), nor any evidence that the family and kenneled populations originated from different genetic pools. Thus, the behavior difference between the groups more likely reflects a G × E interaction, that is, the influence of specific genetic variants manifesting under specific environmental conditions (kennel life). Nevertheless, some kenneled individuals were (genetically) more resistant to social and environmental deprivation. Selecting for such animals could strongly improve the welfare of kenneled dog populations. Moreover, exploring the genetic background of their higher resilience could also help to better understand the genetics behind stress- and fear-related behaviors.

Behavioral development in children with prenatal substance exposure and neonatal abstinence syndrome: Associated factors and implications.

Prenatal substance exposure and neonatal abstinence syndrome (NAS) are risk factors for adverse behavioral outcomes in children at 24 months of age. The purpose of this study was to examine factors associated with abnormal behavioral development in children with prenatal substance exposure or NAS through 10 years of age. A retrospective, nonexperimental, longitudinal design to examine the effects of prenatal substance exposure and NAS on behavioral development at 1, 5, and 10 years of age, while controlling for intrapersonal, interpersonal, community, organizational, and public policy characteristics. A hierarchical multivariate logistic regression model was used to evaluate the influence of substance exposure and NAS on behavioral outcomes. Abnormal behavioral development was predicted at 10 years of age with polysubstance exposure to three substances (odds ratio [OR] = 2.711, p < 0.01) and NAS (OR = 2.077, p < .001). Psychiatric nursing care for children with prenatal substance exposure and NAS should include implementation of early and continued behavioral evaluation and childhood trauma and adversity surveillance in children through middle childhood.

Microglia in the developing prefrontal cortex of rats show dynamic changes following neonatal disconnection of the ventral hippocampus

Impaired ventral hippocampal (VH)-prefrontal cortex (PFC) connectivity is implicated in many cognitive and behavioral disorders. Excitotoxic neonatal VH (nVH) lesion in rat pups has been shown to induce synaptic pruning in the PFC as well as behavioral changes of relevance to developmental neuropsychiatric disorders. In the current study, we hypothesized that microglia, immune cells required for proper brain development and plasticity, may play a role in the development of abnormal behaviors in the nVH-lesioned animals. Ibotenic acid-induced nVH lesion was induced in postnatal day (P)7 male rats. Developmental changes in microglial density, morphology, ultrastructure and gene expression were analyzed in the PFC at P20 and P60. Our results revealed increased microglial reactivity and phagocytic activity in the lesioned rats at P20. Increased mRNA levels of C3 and C1q, complement molecules involved in synaptic pruning, were concomitantly observed. Diminished, but maintained, microglial reactivity and reduced antioxidative defenses were identified in lesioned rats at P60. Behavioral deficits were significantly reduced in the post-pubertal rats by suppressing microglial reactivity by a one-week minocycline treatment immediately after the lesion, These results suggest that early-life disconnection of the VH has long-lasting consequences for microglial functions in the connected structures. Alterations in microglia may underlie synaptic reorganization and behavioral deficits observed following neonatal VH disconnection.

Role of Prefrontal Cortex Anti- and Pro-inflammatory Cytokines in the Development of Abnormal Behaviors Induced by Disconnection of the Ventral Hippocampus in Neonate Rats.

Neonatal disconnection of ventral hippocampus (VH) outputs in rats has been reported to lead to post-pubertal behavioral and synaptic changes of relevance to schizophrenia. Increased oxidative and inflammatory load in the prefrontal cortex (PFC) has been suggested to mediate some of the effects of neonatal VH lesion (NVHL). In this study, we hypothesized that developmental imbalance of anti- and pro-inflammatory factors within the PFC might affect synaptic development thus contributing to the adult NVHL-induced behavioral deficits. Ibotenic acid-induced excitotoxic NVHL was performed in postnatal day (PD) 7 male Sprague-Dawley rats and the mRNA levels of select pro- and anti-inflammatory cytokines were measured in the medial PFC (mPFC) at two developmental time points (PD15 and PD60). We observed a development-specific increase of pro-inflammatory cytokine, interleukin (IL)-1β mRNA at PD15, and an overall reduction in the expression and signaling of transforming growth factor beta 1 (TGF-β1), an anti-inflammatory cytokine, at both PD15 and PD60 in the NVHL animals. These cytokine changes were not seen in the somatosensory cortex (SSC) or tissue surrounding the lesion site. Daily administration of systemic recombinant TGF-β1 from PD7-14 prevented the appearance of hyperlocomotion, deficits in prepulse inhibition (PPI) of startle and social interaction (SI) in post-pubertal (PD60) NVHL rats. Neonatal supplementation of TGF-β1 was also able to attenuate dendritic spine loss in the layer 3 mPFC pyramidal neurons of NVHL animals. These results suggest that early damage of the VH has long-lasting inflammatory consequences in distant connected structures, and that TGF-β1 has potential to confer protection against the deleterious effects of developmental hippocampal damage.

The genetic architecture of socially-affected traits: a GWAS for direct and indirect genetic effects on survival time in laying hens showing cannibalism

BackgroundCannibalism is an important welfare problem in the layer industry. Cannibalism is a social behavior where individual survival is affected by direct genetic effects (DGE) and indirect genetic effects (IGE). Previous studies analysed repeated binomial survival, instead of survival time, which improved accuracies of breeding value predictions. Our study aimed at identifying SNPs associated with DGE and IGE for survival time, and comparing results from models that analyse survival time and repeated binomial survival.MethodsSurvival data of three layer crosses (W1 * WA, W1 * WB, and W1 * WC) were used. Each individual had one survival time record and 13 monthly survival (0/1) records. Approximately 30,000 single nucleotide polymorphisms (SNPs) were included in the genome-wide association study (GWAS), using a linear mixed model for survival time, a linear mixed model and a generalized linear mixed model for repeated binomial survival (0/1). Backwards elimination was used to determine phenotypic and genetic variance explained by SNPs.ResultsThe same quantitative trait loci were identified with all models. A SNP associated with DGE was found in cross W1 * WA, with an allele substitution effect of 22 days. This SNP explained 3% of the phenotypic variance, and 36% of the total genetic variance. Four SNPs associated with DGE were found in cross W1 * WB, with effects ranging from 16 to 35 days. These SNPs explained 1 to 6% of the phenotypic variance and 9 to 44% of the total genetic variance. Our results suggest a link of DGE and IGE for survival time in layers with the gamma-aminobutyric acid (GABA) system, since a SNP located near a gene for a GABA receptor was associated with DGE and with IGE (not significant).ConclusionsThis is one of the first large studies investigating the genetic architecture of a socially-affected trait. The power to detect SNP associations was relatively low and thus we expect that many effects on DGE and IGE remained undetected. Yet, GWAS results revealed SNPs with large DGE and a link of DGE and IGE for survival time in layers with the GABAergic system, which supports existing evidence for the involvement of GABA in the development of abnormal behaviors.

Cerebellar contribution to locomotor behavior: A neurodevelopmental perspective.

The developmental trajectory of the formation of cerebellar circuitry has significant implications for locomotor plasticity and adaptive learning at later stages. While there is a wealth of knowledge on the development of locomotor behavior in human infants, children, and adolescents, pre-clinical animal models have fallen behind on the study of the emergence of behavioral motifs in locomotor function across postnatal development. Since cerebellar development is protracted, it is subject to higher risk of genetic or environmental disruption, potentially leading to abnormal behavioral development. This highlights the need for more sophisticated and specific functional analyses of adaptive cerebellar behavior within the context of whole-body locomotion across the entire span of postnatal development. Here we review evidence on cerebellar contribution to adaptive locomotor behavior, highlighting methodologies employed to quantify and categorize behavior at different developmental stages, with the ultimate goal of following the course of early behavioral alterations in neurodevelopmental disorders. Since experimental paradigms used to study cerebellar behavior are lacking in both specificity and applicability to locomotor contexts, we highlight the use of the Erasmus Ladder - an advanced, computerized, fully automated system to quantify adaptive cerebellar learning in conjunction with locomotor function. Finally, we emphasize the need to develop objective, quantitative, behavioral tasks which can track changes in developmental trajectories rather than endpoint measurement at the adult stage of behavior.

Prenatal neurogenesis induction therapy normalizes brain structure and function in Down syndrome mice

Down syndrome (DS) caused by trisomy of chromosome 21 is the most common genetic cause of intellectual disability. Although the prenatal diagnosis of DS has become feasible, there are no therapies available for the rescue of DS-related neurocognitive impairment. A growth inducer newly identified in our screen of neural stem cells (NSCs) has potent inhibitory activity against dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) and was found to rescue proliferative deficits in Ts65Dn-derived neurospheres and human NSCs derived from individuals with DS. The oral administration of this compound, named ALGERNON (altered generation of neurons), restored NSC proliferation in murine models of DS and increased the number of newborn neurons. Moreover, administration of ALGERNON to pregnant dams rescued aberrant cortical formation in DS mouse embryos and prevented the development of abnormal behaviors in DS offspring. These data suggest that the neurogenic phenotype of DS can be prevented by ALGERNON prenatal therapy.

The gray matter: Prevention and reduction of abnormal behavior in companion gray parrots (Psittacus erithacus)

Abstract Gray parrots ( Psittacus erithacus ) are popular companion birds, particularly noted for their ability to mimic human speech, their intelligence, and longevity. They are also prone to developing abnormal behaviors such as feather damaging behavior. This review explores the current available knowledge on gray parrots kept as companion birds with respect to behavioral problems and their management. The potential causes for the development of abnormal behaviors in this species are explored. Recommendations are made for future research, and advice is provided on the synthesis and application of available research to owners, breeders, and clinicians of gray parrots so that their well-being is maximized in captivity.

The ROCK Inhibitor Fasudil Prevents Chronic Restraint Stress-Induced Depressive-Like Behaviors and Dendritic Spine Loss in Rat Hippocampus.

Background:Dendritic arbor simplification and dendritic spine loss in the hippocampus, a limbic structure implicated in mood disorders, are assumed to contribute to symptoms of depression. These morphological changes imply modifications in dendritic cytoskeleton. Rho GTPases are regulators of actin dynamics through their effector Rho kinase. We have reported that chronic stress promotes depressive-like behaviors in rats along with dendritic spine loss in apical dendrites of hippocampal pyramidal neurons, changes associated with Rho kinase activation. The present study proposes that the Rho kinase inhibitor Fasudil may prevent the stress-induced behavior and dendritic spine loss.Methods:Adult male Sprague-Dawley rats were injected with saline or Fasudil (i.p., 10 mg/kg) starting 4 days prior to and maintained during the restraint stress procedure (2.5 h/d for 14 days). Nonstressed control animals were injected with saline or Fasudil for 18 days. At 24 hours after treatment, forced swimming test, Golgi-staining, and immuno-western blot were performed.Results:Fasudil prevented stress-induced immobility observed in the forced swimming test. On the other hand, Fasudil-treated control animals showed behavioral patterns similar to those of saline-treated controls. Furthermore, we observed that stress induced an increase in the phosphorylation of MYPT1 in the hippocampus, an exclusive target of Rho kinase. This change was accompanied by dendritic spine loss of apical dendrites of pyramidal hippocampal neurons. Interestingly, increased pMYPT1 levels and spine loss were both prevented by Fasudil administration.Conclusion:Our findings suggest that Fasudil may prevent the development of abnormal behavior and spine loss induced by chronic stress by blocking Rho kinase activity.