Effects Of Environmental Enrichment Research Articles

Modulating chronic outcomes after pediatric traumatic brain injury: Distinct effects of social and environmental enrichment

Impairments in social and cognitive function are a common consequence of pediatric traumatic brain injury (TBI). Rehabilitation has the potential to promote optimal behavioral recovery. Here, we evaluated whether an enhanced social and/or cognitive environment could improve long-term outcomes in a preclinical model of pediatric TBI. Male C57Bl/6 J mice received a moderately-severe TBI or sham procedure at postnatal day 21. After one week, mice were randomized to different social conditions (minimal socialization, n = 2/cage; or social grouping, n = 6/cage), and housing conditions (standard cage, or environmental enrichment (EE), incorporating sensory, motor, and cognitive stimuli). After 8 weeks, neurobehavioral outcomes were assessed, followed by post-mortem neuropathology. We found that TBI mice exhibited hyperactivity, spatial memory deficits, reduced anxiety-like behavior, and reduced sensorimotor performance compared to age-matched sham controls. Pro-social and sociosexual behaviors were also reduced in TBI mice. EE increased sensorimotor performance, and the duration of sociosexual interactions. Conversely, social housing reduced hyperactivity and altered anxiety-like behavior in TBI mice, and reduced same-sex social investigation. TBI mice showed impaired spatial memory retention, except for TBI mice exposed to both EE and group housing. In the brain, while TBI led to significant regional tissue atrophy, social housing had modest neuroprotective effects on hippocampal volumes, neurogenesis, and oligodendrocyte progenitor numbers. In conclusion, manipulation of the post-injury environment has benefit for chronic behavioral outcomes, but the benefits are specific to the type of enrichment available. This study improves understanding of modifiable factors that may be harnessed to optimize long-term outcomes for survivors of early-life TBI.

Reorganization of Brain Networks as a Substrate of Resilience: An Analysis of Cytochrome c Oxidase Activity in Rats.

The unpredictable chronic mild stress (UCMS) model has been used to induce depressive-like symptoms in animal models, showing adequate predictive validity. Our work aims to evaluate the effects of environmental enrichment (EE) on resilience in this experimental model of depression. We also aim to assess changes in brain connectivity using cytochrome c oxidase histochemistry in cerebral regions related to cognitive-affective processes associated with depressive disorder: dorsal hippocampus, prefrontal cortex, amygdala, accumbens, and habenula nuclei. Five groups of rats were used: UCMS, EE, EE+UCMS (enrichment+stress), BG (basal level of brain activity), and CONT (behavioral tests only). We assessed the hedonic responses elicited by sucrose solution using a consumption test; the anxiety level was evaluated using the elevated zero maze test, and the unconditioned fear responses were assessed by the cat odor test. The behavioral results showed that the UCMS protocol induces elevated anhedonia and anxiety. But these responses are attenuated previous exposure to EE. Regarding brain activity, the UCMS group showed greater activity in the habenula compared to the EE+UCMS group. EE induced a functional reorganization of brain activity. The EE+UCMS and UCMS groups showed different patterns of connections between brain regions. Our results showed that EE favors greater resilience and could reduce vulnerability to disorders such as depression and anxiety, modifying metabolic brain activity.

Performance and Welfare of Sows Exposed to Auditory Environmental Enrichment in Mixed or Collective Housing Systems

The research aimed to assess the effects of auditory environmental enrichment on sows in mixed housing (caged until 35 days after insemination and then collective pens) or collective housing (caged until 72 h after insemination and then collective pens). Reproductive performance, body surface and eye temperature (ET) were evaluated as sows' welfare indicators. A sample of 56 sows between 2nd and 6th parity was submitted to the treatments from artificial insemination to weaning. The sows were assigned in a randomized block design with a 2 × 2 factorial scheme of treatments: mixed housing-control (MH-C), collective housing-control (CH-C), mixed housing-music (MH-M) and collective housing-music (CH-M). Auditory enrichment consisted of exposing sows daily throughout gestation and lactation to 6 h of classical music divided into 2 h periods. The ET of pregnant sows in collective housing was lower than that of sows in mixed housing (33.77 °C vs. 34.91 °C). Pregnant and lactating sows exposed to auditory environmental enrichment exhibited lower ET compared to those that had no access to the stimulus (pregnant 33.36 °C vs. 34.32 °C and lactating 34.21 °C vs. 34.83 °C). No housing type effect was found on the reproductive performance parameter; however, piglets from sows submitted to auditory environmental enrichment, regardless of the type of housing during gestation, were heavier at weaning (6.32 kg vs. 5.57 kg). Collective or mixed housing does not affect sows' reproductive performance; perhaps, auditory environmental enrichment reduced stress in the gestation and lactation phases and provided greater piglet weight gain at weaning.

Environmental Enrichment and Metformin Improve Metabolic Functions, Hippocampal Neuron Survival, and Hippocampal-Dependent Memory in High-Fat/High-Sucrose Diet-Induced Type 2 Diabetic Rats

Background: The Western-style diet-induced type 2 diabetes mellitus (T2D) may eventually trigger neurodegeneration and memory impairment. Thus, it is essential to identify effective therapeutic strategies to overcome T2D complications. This study aimed to investigate the effects of environmental enrichment (EE) and metformin interventions on metabolic dysfunctions, hippocampal neuronal death, and hippocampal-dependent memory impairments in high-fat/high-sucrose (HFS) diet-induced T2D rats. Methods: Thirty-two male rats (200-250 g) were divided into four groups: C group (standard diet + conventional cage); D group (HFS diet + conventional cage); DE group (HFS diet + EE cage/6hr daily); and DM group (HFS diet + metformin + conventional cage). Body weight was measured every week. T-maze tasks, anthropometric, biochemical, histological, and morphometric parameters were measured. The expression changes of hippocampal genes were also analyzed. Results: The anthropometric and biochemical parameters were improved in DE and DM groups compared with the D group. DE and DM groups had significantly higher T-maze percentages than the D group. These groups also had better histological and morphometric parameters than the D group. The interventions of EE and metformin enhanced the expression of hippocampal genes related to neurogenesis and synaptic plasticity (BDNF/TrkB binding, PI3K-Akt, Ras-MAPK, PLCγ-Ca2+, and LTP). Conclusion: Environmental enrichment (EE) and metformin improved metabolic functions, hippocampal neuron survival, and hippocampal-dependent memory in HFS diet-induced T2D rats. The underlying mechanisms of these interventions involved the expression of genes that regulate neurogenesis and synaptic plasticity.

Assessment of Stress Caused by Environmental Changes for Improving the Welfare of Laboratory Beagle Dogs.

Animal stress is influenced by environmental factors, yet only a few studies have evaluated the effects of environmental stress on captive dogs. This study aimed to evaluate the effects of environmental and social enrichment on the stress levels of captive dogs housed in a lab. We assessed stress levels in eight Beagle dogs by measuring their body weight, cortisol levels, a stress hormone, the alkaline phosphatase activity in serum, the number of steps per hour, as well as clinical sign observations in a changed environment for 6 weeks. Four dogs assigned to a control group were raised alone in a relatively narrow place without toys; four dogs assigned to an experimental group were raised together in a relatively large place with toys. The body weight of the control group remained unchanged, while that of the experimental group decreased. Cortisol levels in the control group increased throughout, whereas those in the experimental group increased for up to 2 weeks and decreased thereafter. Consequently, cortisol levels in the experimental group significantly decreased compared to the control group at 6 weeks (p = 0.048). Fighting was observed among the dogs in the experimental group at 3 weeks; thus, one dog was separated from the group. The number of steps per hour was more than twice as high in the experimental than in the control group. Thereby, we determined that social housing, with appropriate companions and environmental enrichment materials, can reduce stress levels in captive dogs more efficiently than in single housing without such materials. Our study provides useful insights for captive animal organizations, such as kenneled dogs' management, to improve animal welfare.

Behavioral analysis of a captive male Bornean orangutan (Pongo pygmaeus) when exposed to environmental changes

Understanding the species-specific behavioral needs of Bornean orangutans (Pongo pygmaeus) has led zoological gardens to focus on creating more natural and stimulating facilities. Studies have documented enhanced welfare through various methods, including environmental enrichment like mixed-species habitats, which could improve animal welfare. This study aimed to evaluate the behavioral adaption following the transfer to a new facility and the possible effects of environmental enrichment on an orangutan in captivity at Aalborg Zoo in Denmark. A newly arrived male was observed for analyzing behavioral changes in the weeks after relocation and introducing two small-clawed Asian otters (Aonyx cinereus) to the facility. Changes in behavior were analyzed using recorded behavior and an ethogram before and after the introduction of the otters. The expression of behaviors associated with stress and individual plasticity was analyzed, and the results indicated a change in the behavioral phenotype in response to the introduction of the otters. The study shows that behaviors associated with stress decreased after the introduction of small-clawed otters, suggesting that it had a positive effect on the behavior of the orangutan.

Effect of postnatal environmental enrichment on LTP induction in the CA1 area of hippocampus of prenatally traffic noise-stressed female rats.

Early-life stress negatively alters mammalian brain programming. Environmental enrichment (EE) has beneficial effects on brain structure and function. This study aimed to evaluate the effects of postnatal environmental enrichment on long-term potentiation (LTP) induction in the hippocampal CA1 area of prenatally stressed female rats. The pregnant Wistar rats were housed in a standard animal room and exposed to traffic noise stress 2 hours/day during the third week of pregnancy. Their offspring either remained intact (ST) or received enrichment (SE) for a month starting from postnatal day 21. The control groups either remained intact (CO) or received enrichment (CE). Basic field excitatory post-synaptic potentials (fEPSPs) were recorded in the CA1 area; then, LTP was induced by high-frequency stimulation. Finally, the serum levels of corticosterone were measured. Our results showed that while the prenatal noise stress decreased the baseline responses of the ST rats when compared to the control rats (P < 0.001), the postnatal EE increased the fEPSPs of both the CE and SE animals when compared to the respective controls. Additionally, high-frequency stimulation (HFS) induced LTP in the fEPSPs of the CO rats (P < 0.001) and failed to induce LTP in the fEPSPs of the ST animals. The enriched condition caused increased potentiation of post-HFS responses in the controls (P < 0.001) and restored the disrupted synaptic plasticity of the CA1 area in the prenatally stressed rats. Likewise, the postnatal EE decreased the elevated serum corticosterone of prenatally stressed offspring (P < 0.001). In conclusion, the postnatal EE restored the stress induced impairment of synaptic plasticity in rats' female offspring.

Maternal separation increased memory function and anxiety without effects of environmental enrichment in male rats

Maternal separation is a detrimental postnatal influence, whereas environmental enrichment is a therapeutic and protective agent. It is unclear if long-term environmental enrichment can compensate for the effects of maternal separation stress on memory-related alterations. This study examined how environmental enrichment affected memory functions, anxiety level, Grin2a, Grin2b, BDNF, and cFos expressions in the maternally separated rats. There are seven groups in this study: control (C), maternal separation+standard cage (MS), maternal separation + enriched cage (MSE), enriched cage (E), the maternal separation that decapitated at postnatal 21 (MS21) and standard cage that decapitated at PN21 (C21) for hormone and gene expression analysis. The maternal separation procedure consisted of postnatal 21 days. Learning and memory performance were determined with the Morris water tank test; anxiety and locomotor activity were examined with the open field and elevated plus-maze test. The expression levels of genes were measured by the RT-PCR method. Blood corticosterone level was evaluated by the ELISA method. Results showed that MS increased memory performance, locomotor activity, and anxiety, but it did not change gene expression levels. An enriched environment did not change the memory performance, locomotor activity, and related gene expression levels. MSE group increased their memory performance, but the anxiety, locomotor activity, and gene expression level did not change. Grin2a, Grin2b, and BDNF gene expression and corticosterone levels increased in the MS21 group. Maternal separation increased memory performance, but it also increased anxiety. Environmental enrichment alone was insufficient to cause alterations in the memory performance.

Comparing the Effects of Environmental Enrichment, Seasonality, and Soft Release on Site Retention and Survivorship of Captive-Reared Eastern Hellbenders (Cryptobranchus alleganiensis alleganiensis)

Translocations of captive-reared animals are commonly used to stabilize declining wildlife populations. However, captive-reared animals are often raised in conditions dissimilar to their release sites and lacking natural characteristics, which could alter movement patterns and postrelease survivorship. These patterns can be further altered by season of release and soft-release conditions. We reared juvenile Eastern Hellbenders (Cryptobranchus alleganiensis alleganiensis) for 18 mo in captivity in one of two conditions: a control condition with low-velocity water flow (unconditioned) or a treatment condition with moving water (conditioned) that simulated natural flow velocities at their intended release site. We divided 4-yr-old Hellbenders (n = 118) into six treatment groups to determine the effects of release season (fall or summer), release type (standard soft release or enhanced soft release), and conditioning (unconditioned or conditioned) on the number of days until first movement, release site retention, and survival. In November 2017, we released 80 radio-tagged individuals (40 conditioned and 40 unconditioned) into soft-release structures in the Blue River, Indiana. In July 2018, we released another 38 radio-tagged individuals (18 conditioned and 20 unconditioned) into soft-release structures at the same site. After release, we tracked each individual one to three times weekly for 10 mo (fall release) or 12 mo (summer release). We found that treatment groups released into caged cobble beds (i.e., enhanced soft release) delayed their first movement and had higher release site retention relative to groups released under caged shelter rocks (i.e., standard soft release). We found that conditioning had a positive effect on survival but only in the treatment group released in the summer. By combining techniques and releasing conditioned individuals in the summer using enhanced soft releases, we increased annual survival of captive-reared Hellbenders from a probability of 0.50 (95% confidence interval [CI] = 0.31–0.79) to 0.74 (95% CI = 0.55–0.99). Our results provide important information about techniques that can be adopted across captive-rearing programs to help maximize the conservation success of Eastern Hellbenders.

Developmental effects of constitutive mTORC1 hyperactivity and environmental enrichment on structural synaptic plasticity and behaviour in a rat model of autism spectrum disorder.

Autism spectrum disorder (ASD) is a neurodevelopmental condition causing a range of social and communication impairments. Although the role of multiple genes and environmental factors has been reported, the effects of the interplay between genes and environment on the onset and progression of the disease remains elusive. We housed wild-type (Tsc2+/+) and tuberous sclerosis 2 deficient (Tsc2+/-) Eker rats (ASD model) in individually ventilated cages or enriched conditions and conducted a series of behavioural tests followed by the histochemical analysis of dendritic spines and plasticity in three age groups (days 45, 90 and 365). The elevated plus-maze test revealed a reduction of anxiety by enrichment, whereas the mobility of young and adult Eker rats in the open field was lower compared to the wild type. In the social interaction test, an enriched environment reduced social contact in the youngest group and increased anogenital exploration in 90- and 365-day-old rats. Self-grooming was increased by environmental enrichment in young and adult rats and decreased in aged Eker rats. Dendritic spine counts revealed an increased spine density in the cingulate gyrus in adult Ekers irrespective of housing conditions, whereas spine density in hippocampal pyramidal neurons was comparable across all genotypes and groups. Morphometric analysis of dendritic spines revealed age-related changes in spine morphology and density, which were responsive to animal genotype and environment. Taken together, our findings suggest that under TSC2 haploinsufficiency and mTORC1 hyperactivity, the expression of behavioural signs and neuroplasticity in Eker rats can be differentially influenced by the developmental stage and environment.

Effect of environmental enrichment on growth performance of early weaned piglets

Effect of environmental enrichment on growth performance of early weaned piglets

Interacting effects of environmental enrichment across multiple generations on early life phenotypes in zebrafish.

The environment plays an important role in an individual's development during early life, however, parents may also influence offspring development through so called "parental effects." We examined the effects of environmental enrichment in zebrafish (Danio rerio) across two generations through the paternal lineage. Fathers and grandfathers were exposed to either standard or high levels of housing enrichment for 4-weeks during adulthood. First-generation (F1) and second-generation (F2) offspring were obtained from controlled breeding and tested as larvae for changes in morphology at hatching stage (72hpf), and in locomotor activity at larval stage (120hpf) in both generations. We found paternal experience of enrichment resulted in changes in trunk length of F1 offspring and changes in spine curvature and dorsal length of F2 offspring, while changes in snout morphology of F2 offspring seemed to be driven by whether grandpaternal and paternal experience of the environment was matched or not. We found that while paternal enrichment increased the frequency of spontaneous movement in F1 and F2 offspring, interacting effects of paternal and grandpaternal enrichment on movement distance were seen in F2 offspring, and that spontaneous movement and the distance that larvae swam are thus distinct phenotypes that were differentially affected by the experiences of previous paternal generations. Taken together, these findings suggest that the parental and grandparental environment influence zebrafish behavior and morphology. The nature of these effects and the design of this study mean that these phenotypes were likely the result of nongenetic transmission through the paternal germline.

Combinatorial therapeutic effect of Environmental Enrichment and a Poly‐herbal formulation against amyloid‐beta induced Alzheimer’s disease in rodents

AbstractBackgroundAlzheimer’s disease (AD), a common form of dementia currently has no single disease‐modifying drug to halt disease progression. Environmental enrichment (EE) has emerged as an effective therapeutic strategy against various brain disorders. Our previous studies have revealed that the phytoformulation BN was effective in improving cognition and working memory in rodent models induced with cholinergic deficits. BN also inhibited tau hyperphosphorylation, increased dendritic arborization, and modulated AKT and MAPK pathways. In the present study, we propose to evaluate the combinatorial effect of BN and EE against AD.MethodA rodent model of AD was created in Wistar rats through bilateral intra‐hippocampal injection of 100 µg/µL amyloid beta(1‐42). After ten days, the animals were randomly divided in to five groups (GII to GVI) and compared with normal animals (GI). The treatment regimen was commenced with GII acting as disease control, GIII receiving BN (844 mg/kg b.w), GIV receiving combined treatment of EE and BN, GV received only EE and GVI receiving the standard drug donepezil (4 mg/kg b.w.) for a period of 28 days. The cognition and spatial learning were assessed using behavioral studies. Gene and protein expression of key molecular targets were performed to gain insights into the molecular mechanism involved in the combination therapy. Amyloid plaque load was detected using thioflavin S, and dendritic morphology was studied using Golgi‐Cox staining. For EE, cages measuring 60×60×60 cm containing a running wheel, play tubes, ladder, balls, toys, and nesting material that are rearranged weekly, were used to study behavioral changes associated with cognitive stimulation.ResultWe found improved exploratory behaviour of the animals in EE when compared to their counterparts in normal cages. Other behavioral patterns like chewing, physical activity, sorting are significantly higher in animals subjected to the combination of EE and therapy when compared to animals treated in the conventional environment. The cognition and behavioral studies coupled with the histopathological results, gene and protein expression studies will help in establishing the molecular mechanism of the combination.ConclusionThe results from this study open up new therapeutic directions involving environmental factors and multi‐targeted therapeutic agents against AD.

Environmental Enrichment Protects Against Cognition Deficits Caused by Sepsis-Associated Encephalopathy.

One of the most serious complications of sepsis is sepsis-associated encephalopathy (SAE), which impairs the cognition ability of survivors. Environmental enrichment (EE) has been demonstrated to alleviate cognition deficits under many kinds of brain injury conditions. However, EE's effects on SAE remain unknown. Therefore, this study aimed to determine EE's effect on cognition disorders under SAE conditions and the underlying mechanism. Adult male rats, subject to SAE or not, were housed under a standard environment (SE) or EE for 30 days. Subsequently, the rats were subjected to cognitive tests, such as the novel object recognition (NOR) test, the Morris water maze (MWM) test, an Open Field (OF) test, the elevated plus maze (EPM) test, and a sensory neglect (SN) test. Neuroinflammation, apoptosis, and oxidative stress changes in the brain were also detected. The results revealed that SAE impaired somatesthesia, recognition memory, spatial learning and memory, and exploratory activity, which were significantly improved by EE housing. EE also prevented SAE-induced anxiety-like behavior. In addition, EE housing capable induced a decrease in pro-inflammatory cytokines, and an increase in anti-inflammatory cytokines and antioxidant properties in the brain. Moreover, EE housing exerted an anti-apoptosis function by upregulating the level of B-cell lymphoma/leukemia-2 (Bcl-2) level and downregulating the level of p53 level in the hippocampus. The results of the present study indicated that EE exerts a neuroprotective function on cognitive ability in SAE rats. The effect is achieved by increasing antioxidants, and anti-inflammatory and antiapoptotic capacities. EE can effectively rescue SAE-induced cognitive deficits.

Phosphoproteomic dysregulation in Huntington's disease mice is rescued by environmental enrichment.

Huntington's disease is a fatal autosomal-dominant neurodegenerative disorder, characterized by neuronal cell dysfunction and loss, primarily in the striatum, cortex and hippocampus, causing motor, cognitive and psychiatric impairments. Unfortunately, no treatments are yet available to modify the progression of the disease. Recent evidence from Huntington's disease mouse models suggests that protein phosphorylation (catalysed by kinases and hydrolysed by phosphatases) might be dysregulated, making this major post-translational modification a potential area of interest to find novel therapeutic targets. Furthermore, environmental enrichment, used to model an active lifestyle in preclinical models, has been shown to alleviate Huntington's disease-related motor and cognitive symptoms. However, the molecular mechanisms leading to these therapeutic effects are still largely unknown. In this study, we applied a phosphoproteomics approach combined with proteomic analyses on brain samples from pre-motor symptomatic R6/1 Huntington's disease male mice and their wild-type littermates, after being housed either in environmental enrichment conditions, or in standard housing conditions from 4 to 8 weeks of age (n = 6 per group). We hypothesized that protein phosphorylation dysregulations occur prior to motor onset in this mouse model, in two highly affected brain regions, the striatum and hippocampus. Furthermore, we hypothesized that these phosphoproteome alterations are rescued by environmental enrichment. When comparing 8-week-old Huntington's disease mice and wild-type mice in standard housing conditions, our analysis revealed 229 differentially phosphorylated peptides in the striatum, compared with only 15 differentially phosphorylated peptides in the hippocampus (statistical thresholds fold discovery rate 0.05, fold change 1.5). At the same disease stage, minor differences were found in protein levels, with 24 and 22 proteins dysregulated in the striatum and hippocampus, respectively. Notably, we found no differences in striatal protein phosphorylation and protein expression when comparing Huntington's disease mice and their wild-type littermates in environmentally enriched conditions. In the hippocampus, only four peptides were differentially phosphorylated between the two genotypes under environmentally enriched conditions, and 22 proteins were differentially expressed. Together, our data indicates that protein phosphorylation dysregulations occur in the striatum of Huntington's disease mice, prior to motor symptoms, and that the kinases and phosphatases leading to these changes in protein phosphorylation might be viable drug targets to consider for this disorder. Furthermore, we show that an early environmental intervention was able to rescue the changes observed in protein expression and phosphorylation in the striatum of Huntington's disease mice and might underlie the beneficial effects of environmental enrichment, thus identifying novel therapeutic targets.

Environmental enrichment for primiparous and multiparous pregnant sows and its effect on cortisol and behavior at farrowing and production parameters at weaning

The study evaluated the effect of environmental enrichment (EE) during gestation of primiparous and multiparous sows on the concentrations of cortisol, behavior at farrowing, and production parameters of sows and their piglets. Primiparous (n = 20) and multiparous (n = 20) sows were included. Half of the sows received EE from Week 6 to Week 14 of gestation, while the remaining sows received no EE. The concentrations of hair cortisol on Weeks 6 and 15 of gestation, the behavior of the sows before, during, and after parturition, and some production parameters of the sows and their piglets at birth and weaning were compared among groups. Cortisol increased from Week 6 through Week 15 in all the sows and it was greater in those with no EE. Before, during, and after parturition the primiparous sows that received EE showed behavioral patterns suggestive of better dealing with stress and pain, in comparison mainly with primiparous sows that received no EE. The number of piglets born alive, the total of piglets born, and the weight at birth by litter were similar (P > 0.05) in all groups. The weight at weaning by litter was greater (P < 0.05) for piglets of primiparous sows with EE and less (P < 0.05) for piglets of primiparous sows with no EE. In conclusion, providing sows, particularly gilts, with EE during gestation reduced their stress and pain during parturition, and improved the weight gain in their piglets.

Reelin protects against pathological α-synuclein accumulation and dopaminergic neurodegeneration after environmental enrichment in Parkinson's disease

Two of the primary features of Parkinson's disease (PD) are the accumulation of α-synuclein (α-Syn) and the depletion of lysosomal-associated membrane protein 1 (LAMP1) in the brain. Beneficial effects of environmental enrichment (EE) have been reported on the activation of lysosomal function and the amelioration of PD symptoms. Furthermore, Reelin could be a novel therapeutic target in PD. Hence, in this study, we validated the effects of EE on the activation of LAMP1 via Reelin in PD. Heterogeneous α-Syn (A53T)-overexpressing transgenic mice (age 6 and 16 months) were exposed to EE for 8 weeks. After motor and cognitive tests, brain tissues were obtained from mice and subjected to immunohistochemistry and molecular analyses. EE ameliorated motor and non-motor symptoms, protected dopamine neurons, and reduced pathological α-Syn accumulation in the early stage of PD. Striatal Reelin levels were altered depending on the disease stage and regulated by EE in PD mice. To elucidate the underlying mechanism of the effect of EE on PD, we performed further molecular and cellular analyses using activated preformed fibril (PFF)-induced SH-SY5Y cells, an in vitro model of PD, which were treated with recombinant Reelin protein and a Reelin blocker, CR-50. The CR-50 increased pathological α-Syn accumulation and accelerated dopamine neuronal degeneration by decreasing LAMP1 in the PFF-induced PD model. Our results showed that Reelin increased LAMP1 after EE and decreased pathological α-Syn accumulation, thus protecting dopamine neurons from degeneration in the striatum and substantia nigra, and ameliorating neurobehavioral deficits. These results suggest that Reelin is a promising target in treating histopathological changes and improving behavioral symptoms associated with PD.

The Influence of Environmental Enrichment on Affective and Neural Consequences of Social Isolation Across Development.

Social stress is associated with depression and anxiety, physiological disruptions, and altered brain morphology in central stress circuitry across development. Environmental enrichment strategies may improve responses to social stress. Socially monogamous prairie voles exhibit analogous social and emotion-related behaviors to humans, with potential translational insight into interactions of social stress, age, and environmental enrichment. This study explored the effects of social isolation and environmental enrichment on behaviors related to depression and anxiety, physiological indicators of stress, and dendritic structural changes in amygdala and hippocampal subregions in young adult and aging prairie voles. Forty-nine male prairie voles were assigned to one of six groups divided by age (young adult vs. aging), social structure (paired vs. isolated), and housing environment (enriched vs. non-enriched). Following 4 weeks of these conditions, behaviors related to depression and anxiety were investigated in the forced swim test and elevated plus maze, body and adrenal weights were evaluated, and dendritic morphology analyses were conducted in hippocampus and amygdala subregions. Environmental enrichment decreased immobility duration in the forced swim test, increased open arm exploration in the elevated plus maze, and reduced adrenal/body weight ratio in aging and young adult prairie voles. Age and social isolation influenced dendritic morphology in the basolateral amygdala. Age, but not social isolation, influenced dendritic morphology in the hippocampal dentate gyrus. Environmental enrichment did not influence dendritic morphology in either brain region. These data may inform interventions to reduce the effects of social stressors and age-related central changes associated with affective behavioral consequences in humans.

Effects of environmental enrichments on ovarian development of Buitta Catfish (Sperata sp.: Family Bagridae) in captivity

Environmental enrichment (EE) is an important factor that helps improve both the physical and psychological behavior of farmed animals. This factor also controls social interactions and provides more stimulants to influence the reproductive performance of animals in captivity. As EE plays an important role in animal reproduction, the present study was designed to investigate the effects of different types of tank bottom enrichments on the ovarian development of Buitta (Sperata sp.) catfish in captivity. Barren (TA), muddy (TB), and sandy (TC) enrichments were utilized for four months to observe the physical and psychological changes of the catfish. The results showed significant differences (p < 0.05) in the weight gain, gonadosomatic index (GSI), and hepatosomatic index (HSI) of the fish, however, no significant difference was found in the fish fecundity. The most prominent changes include weight, ripeness, the biochemical composition of body tissues, and the frequency distribution of the migratory nucleus in the oocytes. Moreover, the diameter of oocytes that occurred in the enrichment TC (p < 0.05) was significantly higher than the enrichments TA and TB. Histological observation found at least two stages of the ovarian oocytes development process in each ovary indicating the asynchronous self-reproduction of the fish. Additionally, biological macromolecules analysis found higher protein content in the muscle (86.04%), liver (52.97%), and oocyte (64.71%) and a higher deposition of lipid within the oocytes (32.33%) and liver (27.06%) for enrichment TC, while these values were lower for the other two treatments. Finally, the study suggests that a sandy environment should be used to obtain an acceptable level of oocyte development in the female Buitta fish in captivity.

Effects of different environmental enrichments on the behavioral patterns, growth performance, hematological, and hormonal changes in Japanese quail.

Effects of different environmental enrichments on the behavioral patterns, growth performance, hematological, and hormonal changes in Japanese quail.