The core symptoms of autism spectrum disorder (ASD) include deficits in social interaction, impaired communication, and repetitive behaviors with restricted interests. Mouse models with behavioral ...phenotypes relevant to these core symptoms offer an experimental approach to advance the investigation of genes associated with ASD. Previous findings demonstrate that BTBR T+ tf/J (BTBR) is an inbred mouse strain that shows robust behavioral phenotypes with analogies to all three of the diagnostic symptoms of ASD. In the present study, we investigated the expression of social behaviors in a semi-natural visible burrow system (VBS), during colony formation and maintenance in groups comprising three adult male mice of the same strain, either C57BL/6J (B6) or BTBR. For comparative purposes, an extensively investigated three-chambered test was subsequently used to assess social approach in both strains. The effects of strain on these two situations were consistent and highly significant. In the VBS, BTBR mice showed reductions in all interactive behaviors: approach (front and back), flight, chase/follow, allo-grooming and huddling, along with increases in self-grooming and alone, as compared to B6. These results were corroborated in the three-chambered test: in contrast to B6, male BTBR mice failed to spend more time in the side of the test box containing the unfamiliar CD-1 mouse. Overall, the present data indicates that the strain profile for BTBR mice, including consistent social deficits and high levels of repetitive self-grooming, models multiple components of the ASD phenotype.
1. Anthropocene defaunation is the global phenomenon of human-induced animal biodiversity loss. Understanding the patterns and process of defaunation is critical to predict outcomes for wildlife ...populations and cascading consequences for ecosystem function and human welfare. 2. We investigated a defaunation gradient in north-eastern Gabon by establishing 24 transects at varying distances (2-30 km) to rural villages and surveying the abundance and composition of vertebrate communities. Distance from village was positively correlated with observations of hunting (shotgun shells, campfires, hunters), making it a good proxy for hunting pressure. 3. Species diversity declined significantly with proximity to village, with mammal richness increasing by roughly 1-5 species every 10 km travelled away from a village. Compared to forest far from villages, the wildlife community near villages consisted of higher abundances of large birds and rodents and lower abundances of large mammals like monkeys and ungulates. 4. Distance to nearest village emerged as a key driver of the relative abundance of five of the six taxonomic guilds, indicating that the top-down force of hunting strongly influences large vertebrate community composition and structure. Several measures of vegetation structure also explained animal abundance, but these varied across taxonomic guilds. Forest elephants were the exception: no measured variable or combination of variables explained variation in elephant abundances. 5. Synthesis and applications. Hunting is concentrated within 10 km around villages, creating a hunting halo characterized by heavily altered animal communities composed of relatively small-bodied species. Although the strongest anthropogenic effects are relatively distance-limited, the linear increase in species richness shown here even at distances 30 km from villages suggests that hunting may have altered vertebrate abundances across the entire landscape. Central African forests store > 25% of the carbon in tropical forests and are home to 3000 endemic species, but roughly 53% of the region lies within the village hunting halo. Resource management strategies should take into account this hunting-induced spatial variation in animal communities. Near villages, resource management should focus on sustainable community-led hunting programmes that provide long-term supplies of wild meat to rural people. Resource management far from villages should focus on law enforcement and promoting industry practices that maintain remote tracts of land to preserve ecosystem services like carbon storage and biodiversity.
Social anhedonia has been employed in psychometric high-risk studies to identify putative schizotypes. To date, this research has focused almost exclusively on college samples. The current study ...sought to examine the validity of social anhedonia as an indicator of risk for schizophrenia-spectrum disorders within a community sample. Furthermore, we evaluated the role of other individual difference variables in accounting for variable clinical severity within the social anhedonia group including trait affectivity, social support, and family environment. Following the mailed questionnaire screening of 2434 eighteen-year olds, laboratory assessments were conducted with individuals identified as being high in social anhedonia (n=86) and a comparison sample (n=89). Compared with the control group, individuals in the social anhedonia group were found to have higher rates of mood disorders, elevated schizophrenia-spectrum personality disorder characteristics, greater negative symptom characteristics, and lower global functioning. Individuals within the social anhedonia group also reported greater trait negative affectivity, lower positive affectivity, less social support, and more family conflict. Low social support and problematic family environment were found to be related to elevations in spectrum personality disorder characteristics and poorer functioning within the social anhedonia group. These cross-sectional findings from a community sample provide further support for social anhedonia as a possible indicator of schizotypy.
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•Implementation of code for fitting zero- to ultralow-field (ZULF) NMR data.•Spin-spin couplings determined with uncertainty as low as 200μHz.•Improved precision for some couplings by ...up to 100×.•Spin-spin couplings reported for neat liquids (no 2H lock solvents, etc.).
We present a method which allows for the extraction of physical quantities directly from zero- to ultralow-field nuclear magnetic resonance (ZULF NMR) data. A numerical density matrix evolution is used to simulate ZULF NMR spectra of several molecules in order to fit experimental data. The method is utilized to determine the indirect spin-spin couplings (J-couplings) in these systems, which is achieved with precision of 10-2–10-4Hz. The simulated and measured spectra are compared to earlier research. Agreement and improved precision are achieved for most of the J-coupling estimates. The availability of fast, flexible fitting method for ZULF NMR enables a new generation of precision-measurement experiments for spin-dependent interactions and physics beyond the Standard Model.
In an earlier article (Langmuir 2016, 32, 9507–9512), we reported the existence of an induced charge density gradient, ρf, in a room-temperature ionic liquid (RTIL, BMIM+BF4 –) normal to a charged ...planar silica surface. In this work, we demonstrate experimental control over the sign and magnitude of the gradient. The spatial extent of ρf can exceed 100 μm from the charged surface. We characterized ρf through the rotational diffusion time constant gradient of a cationic chromophore in the room-temperature ionic liquid (RTIL). The sign and magnitude of ρf in BMIM+BF4 – is linked directly to the surface charge density of the electrode, which can be controlled. We used transparent conductive electrodes (FTO and ITO coated on glass) as supports and demonstrated that control over the electrode surface charge carrier density can influence the magnitude and sign of ρf. There are limitations to this approach based on the FTO and ITO properties, and we demonstrate these limits experimentally.
A wealth of studies has implicated oxytocin (Oxt) and its receptors (Oxtr) in the mediation of social behaviors and social memory in rodents. It has been suggested that failures in this system ...contribute to deficits in social interaction that characterize autism spectrum disorders (ASD). In the current analyses, we investigated the expression of autism-related behaviors in mice that lack the ability to synthesize the oxytocin receptor itself, Oxtr knockout (KO) mice, as compared to their wild-type (WT) littermates. In the visible burrow system, Oxtr KO mice showed robust reductions in frontal approach, huddling, allo-grooming, and flight, with more time spent alone, and in self-grooming, as compared to WT. These results were corroborated in the three-chambered test: unlike WT, Oxtr KO mice failed to spend more time in the side of the test box containing an unfamiliar CD-1 mouse. In the social proximity test, Oxtr KO mice showed clear reductions in nose to nose and anogenital sniff behaviors oriented to an unfamiliar C57BL/6J (B6) mouse. In addition, our study revealed no differences between Oxtr WT and KO genotypes in the occurrence of motor and cognitive stereotyped behaviors. A significant genotype effect was found in the scent marking analysis, with Oxtr KO mice showing a decreased number of scent marks, as compared to WT. Overall, the present data indicate that the profile for Oxtr KO mice, including consistent social deficits, and reduced levels of communication, models multiple components of the ASD phenotype.
This article is part of a Special Issue entitled Oxytocin, Vasopressin, and Social Behavior.
► Oxtr KO mice display consistent social deficits in a semi-natural VBS. ► The social deficits of Oxtr KO mice are corroborated in the three chamber and social proximity tests. ► Oxtr KO mice do not show altered expression of motor and cognitive stereotyped behaviors. ► Oxtr KO mice exhibit reduced levels of communication. ► The profile for Oxtr KO mice models multiple components of the ASD phenotype.
The natural defensive behaviors of laboratory mice have been evaluated in both seminatural and highly structured situations; and characterized in terms of eliciting stimuli, response to ...pharmacological agents, behavior patterns, and outcome or effect on the social and physical environment. The defense patterns of laboratory mice and rats are generally similar, but mice show risk assessment on initial exposure to highly threatening stimuli while rats do not, while rats display alarm vocalizations, missing in mice. Quantitative differences in freezing and flight for laboratory mice and rats appear to largely reflect domestication effects, with wild mice and rats more similar to each other. This nexus of detailed within-species and comparative data on defense patterns makes it possible to reliably elicit specific defenses in mice or rats in an experimental context, providing well-validated assays of the natural defensive behaviors themselves, as opposed to `models’ of defense.
The mouse–rat comparisons indicate considerable cross-species generality for these defense patterns, as does a scattered but considerable literature on other mammalian species, generally involving field studies and typically focusing on those aspects of defensive behavior that are visible at a distance, such as vigilance, or flight. Although potential homologies between normal mouse and human defense systems should ideally involve all four pattern components (stimulus, organismic factors, response characteristics, outcome), predictive validity in terms of response to drugs active against specific defensive psychopathology is the most extensively investigated of these. Flight, as measured in the Mouse Defense Test Battery shows a consistently appropriate response to panicolytic, panicogenic, and panic-neutral drugs, while some other predictive ‘panic models’ (dPAG-stimulation; DMH-inhibition; possibly conditioned suppression of drinking paradigms) also elicit and (indirectly) measure behaviors potentially related to flight. Models unrelated to flight (e.g. ultrasonic vocalization to conditioned stimuli); or for which flight elements may a relatively minor contributor to the behavior measured (Elevated T-maze) are less predictive of panicolytic or panicogenic action. These findings indicate that natural defensive behaviors provide a well-characterized pattern for analysis of effects of genetic or other physiological manipulations in the mouse, and may also serve as a model for analysis of defense-related human psychopathology.
The present paper presents original data and a review of the copper (Cu) toxicity literature for estuarine and marine environments. For the first time, acute Cu toxicity across the full salinity ...range was determined. Killifish,
Fundulus heteroclitus, eggs were hatched in freshwater (FW), 2.5, 5, 10, 15, 22 and 35
ppt (seawater, SW) and juveniles were allowed to acclimate for 7 days prior to acute toxicity testing. Sensitivity was highest in FW (96
h LC50: 18
μg/l), followed by SW (96
h LC50: 294
μg/l) with fish at intermediate salinities being the most tolerant (96
h LC50
>
963
μg/l at 10
ppt). This approximately 50-fold, non-linear variation in sensitivity could not be accounted for by Cu speciation or competition among cations but can be explained by physiology. The relative Na
+ gradient from the blood plasma to the water is greatest in FW followed by SW and is smallest at 10
ppt. Regression of Cu toxicity versus the equilibrium potential for Na
+, which reflects the relative Na
+ gradient, revealed that 93% of the variation can be attributed to Na
+ gradients and thus osmoregulatory physiology. Examination of the existing literature on acute Cu toxicity in SW (defined as >25
ppt) confirmed that early life stages generally are most sensitive but this pattern may be attributable to size rather than developmental stage. Regardless of developmental stage and phylogeny, size clearly matters for Cu sensitivity. The existing literature on the influence of salinity on acute Cu toxicity as well as studies of mechanisms of Cu toxicity in fish and invertebrates are reviewed.
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