Do housing-induced changes in brain activity cause stereotypic behaviours in laboratory mice?

Abnormal repetitive stereotypic behaviours (SBs) (e.g. pacing, body-rocking) are common in animals with poor welfare (e.g. socially isolated/in barren housing). But how (or even whether) poor housing alters animals' brains to induce SBs remains uncertain. To date, there is little evidence for environmental effects on the brain that also correlate with individual SB performance. Using female mice from two strains (SB-prone DBA/2s; SB-resistant C57/BL/6s), displaying two forms of SB (route-tracing; bar-mouthing), we investigated how housing (conventional laboratory conditions vs. well-resourced 'enriched' cages) affects long-term neuronal activity as assessed via cytochrome oxidase histochemistry in 13 regions of interest (across cortex, striatum, basal ganglia and thalamus). Conventional housing reduced activity in the cortex and striatum. However, DBA mice had no cortical or striatal differences from C57 mice (just greater basal ganglia output activity, independent of housing). Neural correlates for individual levels of bar-mouthing (positive correlations in the substantia nigra and thalamus) were also independent of housing; while route-tracing levels had no clear neural correlates at all. Thus conventional laboratory housing can suppress cortico-striatal activity, but such changes are unrelated to SB (since not mirrored by congruent individual and strain differences). Furthermore, the neural correlates of SB at individual and strain levels seem to reflect underlying predispositions, not housing-mediated changes. To aid further work, hypothesis-generating model fit analyses highlighted this unexplained housing effect, and also suggested several regions of interest across cortex, striatum, thalamus and substantia nigra for future investigation (ideally with improved power to reduce risks of Type II error).

The role of task preference in the effectiveness of response interruption and redirection

Response interruption and redirection (RIRD) is a common treatment for automatically reinforced vocal stereotypy; it involves the contingent presentation of task instructions. Tasks that are included in RIRD are typically selected based on caregiver report, which may affect the efficacy of RIRD. The purpose of the current study was to evaluate the role of task preference in the efficacy of RIRD for four participants who engaged in vocal stereotypy. We conducted task-preference assessments and selected tasks of varying preferences to include in RIRD. For three out of four participants, the results showed that RIRD with higher preference tasks was not effective at reducing vocal stereotypy, whereas RIRD with lower preference tasks was effective for all participants.

Physiological and behavioural adjustment of a wild rodent to laboratory conditions

Wild animals are brought to captivity for different reasons, for example to be kept in zoos and rehabilitation centres, but also for basic research. Such animals usually undergo a process of adjustment to captive conditions. While this adjustment occurs on the behavioural and the physiological level, those are usually studied separately. The aim of this study was to assess both the physiological and behavioural responses of wild wood mice, Apodemus sylvaticus, while adjusting to laboratory conditions. Over the course of four weeks, we measured in wild-caught mice brought to the laboratory faecal corticosterone metabolites and body mass as physiological parameters, stereotypic behaviour and nest-quality, as welfare-linked behavioural parameters, and four personality measures as additional behavioural parameters. The results of our study indicate that mice exhibited an adjustment in both behaviour and physiology over time in the laboratory. While the hormonal stress response decreased significantly, body mass and the proportion of stereotypic behaviours showed a tendency to increase over time. The slight increase of stereotypic behaviours, although not statistically significant, suggests the development of repetitive and non-functional behaviours as a response to laboratory conditions. However, we suggest that those behaviours might have been used by animals as a coping strategy to decrease the physiological stress response. Other behavioural parameters measured, such as boldness and nestbuilding behaviour were stable over time. The information obtained in the present study hints at a complex interplay between behavioural and physiological adjustments of wild animals to laboratory conditions, which should be considered when intending to use wild animals in experimental research.

Investigating the gastrointestinal physiology of mature horses with and without a history of cribbing behavior in response to feeding a digestive support supplement

Cribbing, a stereotypic oral behavior observed in horses, involves placing incisors on a fixed object, arching the neck, pulling against the object, and emitting an audible grunt. This behavior has been associated with gastrointestinal (GI) dysfunction and gastric ulceration. In this randomized crossover study, we investigated the impact of a GI support supplement (SPL) on the GI environment and physiology of four cribbing (CB) and four non-cribbing horses (NCB). Mature Quarter Horses, acclimated to individual stalls for 16 hours daily with paddock turnout in pairs for 8 hours per day, were randomly assigned to receive either the SPL or placebo for 21 days, followed by a 2-week washout period. Fecal and gastric samples were collected for pH determination and blood samples were analyzed for serum cortisol and gastrin levels. Endoscopic examinations assessed gastric ulcer severity, and cribbing frequency and bouts were recorded via video surveillance. Data were analyzed using a mixed-model ANOVA. Results showed no differences in fecal and gastric pH between cribbing statuses. However, an interaction between supplementation and cribbing status was observed for squamous mucosa ulcer scores (P=0.003). There were no differences in glandular mucosa ulcer scores, serum cortisol, serum gastrin, and crib-bite count between CB and NCB horses or between supplementation groups. Crib-bout duration did not differ with supplementation, but differences were found between periods (P<0.05) and hour ranges (P<0.001). Our findings suggest that the GI support supplement may not effectively address cribbing behavior or alter the GI environment in NCB or CB horses.

Environmental interventions reduced repetitive behavior in a mouse model

Repetitive motor behaviors are associated with several neurodevelopmental disorders including autism spectrum disorder. Non-invasive environmental interventions that can ameliorate repetitive behavior and be introduced in early development could benefit many. In Experiment 1, we characterized the development of repetitive circling in mice reared in standard and enriched environments. Environmental enrichment was associated with reduced repetitive behavior. In Experiment 2, two weekly injections of an A2A adenosine receptor agonist reduced repetitive behavior in mice fed a ketogenic diet. Together, these two approaches modified the environment and reduced repetitive behavior with potential implications for increased functioning of the indirect basal ganglia pathway.

The Partial M1 Muscarinic Cholinergic Receptor Agonist, CDD-0102A, Differentially Modulates Glutamate Efflux in Striatal Subregions during Stereotyped Motor Behavior in the BTBR Mouse Model of Autism

The BTBR T+ Itpr3tf/J (BTBR) mouse displays elevated repetitive motor behaviors. Treatment with the partial M1 muscarinic receptor agonist, CDD-0102A, attenuates stereotyped motor behaviors in BTBR mice. The present experiment investigated whether CDD-0102A modifies changes in striatal glutamate concentrations during stereotyped motor behavior in BTBR and B6 mice. Using glutamate biosensors, change in striatal glutamate efflux was measured during bouts of digging and grooming behavior with a 1 s time resolution. Mice displayed both decreases and increases in glutamate efflux during such behaviors. Magnitude of changes in glutamate efflux (decreases and increases) from dorsomedial and dorsolateral striatum were significantly greater in BTBR mice compared to those of B6 mice. In BTBR mice, CDD-0102A (1.2 mg/kg) administered 30 min prior to testing significantly reduced the magnitude change in glutamate decreases and increases from the dorsolateral striatum and decreased grooming behavior. Conversely, CDD-0102A treatment in B6 mice potentiated glutamate decreases and increases in the dorsolateral striatum and elevated grooming behavior. The findings suggest that activation of M1 muscarinic receptors modifies glutamate transmission in the dorsolateral striatum and self-grooming behavior.

Professional actors demonstrate variability, not stereotypical expressions, when portraying emotional states in photographs

It is long hypothesized that there is a reliable, specific mapping between certain emotional states and the facial movements that express those states. This hypothesis is often tested by asking untrained participants to pose the facial movements they believe they use to express emotions during generic scenarios. Here, we test this hypothesis using, as stimuli, photographs of facial configurations posed by professional actors in response to contextually-rich scenarios. The scenarios portrayed in the photographs were rated by a convenience sample of participants for the extent to which they evoked an instance of 13 emotion categories, and actors' facial poses were coded for their specific movements. Both unsupervised and supervised machine learning find that in these photographs, the actors portrayed emotional states with variable facial configurations; instances of only three emotion categories (fear, happiness, and surprise) were portrayed with moderate reliability and specificity. The photographs were separately rated by another sample of participants for the extent to which they portrayed an instance of the 13 emotion categories; they were rated when presented alone and when presented with their associated scenarios, revealing that emotion inferences by participants also vary in a context-sensitive manner. Together, these findings suggest that facial movements and perceptions of emotion vary by situation and transcend stereotypes of emotional expressions. Future research may build on these findings by incorporating dynamic stimuli rather than photographs and studying a broader range of cultural contexts.

Sodium phenylbutyrate reduces repetitive self-grooming behavior and rescues social and cognitive deficits in mouse models of autism

Autism spectrum disorder (ASD) is a neurodevelopment disorder characterized by deficits in social interaction and restrictive, repetitive, and stereotypical patterns of behavior. However, there is no pharmacological drug that is currently used to target these core ASD symptoms. Sodium phenylbutyrate (NaPB) is a well-known long-term treatment of urea cycle disorders in children. In this study, we assessed the therapeutic effects of NaPB, which is a chemical chaperone as well as histone deacetylase inhibitor on a BTBR T + Itpr3tf/J (BTBR) mice model of ASD. We found that acute and chronic treatment of NaPB remarkably improved, not only core ASD symptoms, including repetitive behaviors and sociability deficit, but also cognitive impairment in the BTBR mice. NaPB substantially induced histone acetylation in the brain of the BTBR mice. Intriguingly, the therapeutic effects of NaPB on autistic-like behaviors, such as repetitive behaviors, impaired sociability, and cognitive deficit also showed in the valproic acid (VPA)-induced mouse model of autism. In addition, pentylenetetrazole (PTZ)-induced seizure was significantly attenuated by NaPB treatment in C57BL/6J and BTBR mice. These findings suggest that NaPB may provide a novel therapeutic approach for the treatment of patients with ASD.

The effects of two stressors on working memory and cognitive flexibility in zebrafish (Danio rerio): The protective role of D1/D5 agonist on stress responses

Acute stressors are recurrent in multiple species' lives and can facilitate or impair cognition. The use of zebrafish (Danio rerio) as a translational species to understand the mechanisms by which stress induces different behavioral phenotypes has been widely studied. Two acute stressors are recognized when using this species: (1) conspecific alarm substance (CAS); and (2) net chasing. Here, we tested if CAS or net chasing would affect working memory and cognitive flexibility by testing performance in the FMP Y-maze after exposure to stress. We observed that CAS altered zebrafish behavioral phenotypes by increasing repetitive behavior; meanwhile, animals showed different patterns of repetitive behavior when exposed to net chasing, depending on the chasing direction. Because D1 receptors were previously studied as a potential mechanism underlying stress responses in different species, here, we pretreated fish with a D1/D5 agonist (SKF-38393) to assess whether this system plays a role in repetitive behavior in the FMP Y-maze. The pretreatment with D1/D5 agonist significantly decreased repetitive behavior in CAS exposed animals, and cortisol levels for both stressed groups, suggesting that the dopaminergic system plays an important role in zebrafish stress-related responses.

Atypical neural processing during the execution of complex sensorimotor behavior in autism

Stereotyped behavior is rhythmic, repetitive movement that is essentially invariant in form. Stereotypy is common in several clinical disorders, such as autism spectrum disorders (ASD), where it is considered maladaptive. However, it also occurs early in typical development (TD) where it is hypothesized to serve as the foundation on which complex, adaptive motor behavior develops. This transition from stereotyped to complex movement in TD is thought to be supported by sensorimotor integration. Stereotypy in clinical disorders may persist due to deficits in sensorimotor integration. The present study assessed whether differences in sensorimotor processing may limit the expression of complex motor behavior in individuals with ASD and contribute to the clinical stereotypy observed in this population. Adult participants with ASD and TD performed a computer-based stimulus-tracking task in the presence and absence of visual feedback. Electroencephalography was recorded during the task. Groups were compared on motor performance (root mean square error), motor complexity (sample entropy), and neural complexity (multiscale sample entropy of the electroencephalography signal) in the presence and absence of visual feedback. No group differences were found for motor performance or motor complexity. The ASD group demonstrated greater neural complexity and greater differences between feedback conditions than TD individuals, specifically in signals relevant to sensorimotor processing. Motor performance and motor complexity correlated with clinical stereotypy in the ASD group. These findings support the hypothesis that individuals with ASD have differences in sensorimotor processing when executing complex motor behavior and that stereotypy is associated with low motor complexity.

Investigating the Matching Relationship between Physical Exercise and Stereotypic Behavior in Children with Autism

PURPOSE

Physical exercise has been shown to be effective in reducing stereotypic behaviors in children with autism spectrum disorder. One possible mechanism concerns the matching hypothesis between exercise and behavior. The present study sought to examine this matching exercise-behavior relationship.

METHODS

Participants (N = 21, 17 males and 4 females, Mage = 11.07 ± 1.44 yr, Mheight = 1.46 ± 0.99 m, and Mweight = 40.60 ± 8.25 kg), with observable forms of hand-flapping and body-rocking stereotypic behaviors, underwent three separate days of conditions, one for the control condition, one for the 10-min ball-tapping exercise condition, and one for the 10-min jogging condition, in a randomized order. The frequency of each type of stereotypic behavior was videotaped from 15 min before to 60 min after the exercise.

RESULTS

Results revealed that only hand-flapping stereotypic behaviors were significantly reduced in the ball-tapping exercise condition (P < 0.017), whereas only body-rocking stereotypic behaviors were significantly reduced in the jogging exercise condition (P < 0.017). However, the behavioral benefit diminished at 45 min after the respective exercise.

CONCLUSION

Physical exercise should be topographically matched with stereotypic behavior to produce desirable behavioral benefits in children with autism spectrum disorder.

A framework to identify structured behavioral patterns within rodent spatial trajectories

Animal behavior is highly structured. Yet, structured behavioral patterns-or "statistical ethograms"-are not immediately apparent from the full spatiotemporal data that behavioral scientists usually collect. Here, we introduce a framework to quantitatively characterize rodent behavior during spatial (e.g., maze) navigation, in terms of movement building blocks or motor primitives. The hypothesis that we pursue is that rodent behavior is characterized by a small number of motor primitives, which are combined over time to produce open-ended movements. We assume motor primitives to be organized in terms of two sparsity principles: each movement is controlled using a limited subset of motor primitives (sparse superposition) and each primitive is active only for time-limited, time-contiguous portions of movements (sparse activity). We formalize this hypothesis using a sparse dictionary learning method, which we use to extract motor primitives from rodent position and velocity data collected during spatial navigation, and successively to reconstruct past trajectories and predict novel ones. Three main results validate our approach. First, rodent behavioral trajectories are robustly reconstructed from incomplete data, performing better than approaches based on standard dimensionality reduction methods, such as principal component analysis, or single sparsity. Second, the motor primitives extracted during one experimental session generalize and afford the accurate reconstruction of rodent behavior across successive experimental sessions in the same or in modified mazes. Third, in our approach the number of motor primitives associated with each maze correlates with independent measures of maze complexity, hence showing that our formalism is sensitive to essential aspects of task structure. The framework introduced here can be used by behavioral scientists and neuroscientists as an aid for behavioral and neural data analysis. Indeed, the extracted motor primitives enable the quantitative characterization of the complexity and similarity between different mazes and behavioral patterns across multiple trials (i.e., habit formation). We provide example uses of this computational framework, showing how it can be used to identify behavioural effects of maze complexity, analyze stereotyped behavior, classify behavioral choices and predict place and grid cell displacement in novel environments.

Adaptive modulation of brain hemodynamics across stereotyped running episodes

During locomotion, theta and gamma rhythms are essential to ensure timely communication between brain structures. However, their metabolic cost and contribution to neuroimaging signals remain elusive. To finely characterize neurovascular interactions during locomotion, we simultaneously recorded mesoscale brain hemodynamics using functional ultrasound (fUS) and local field potentials (LFP) in numerous brain structures of freely-running overtrained rats. Locomotion events were reliably followed by a surge in blood flow in a sequence involving the retrosplenial cortex, dorsal thalamus, dentate gyrus and CA regions successively, with delays ranging from 0.8 to 1.6 seconds after peak speed. Conversely, primary motor cortex was suppressed and subsequently recruited during reward uptake. Surprisingly, brain hemodynamics were strongly modulated across trials within the same recording session; cortical blood flow sharply decreased after 10-20 runs, while hippocampal responses strongly and linearly increased, particularly in the CA regions. This effect occurred while running speed and theta activity remained constant and was accompanied by an increase in the power of hippocampal, but not cortical, high-frequency oscillations (100-150 Hz). Our findings reveal distinct vascular subnetworks modulated across fast and slow timescales and suggest strong hemodynamic adaptation, despite the repetition of a stereotyped behavior.

A pair of ascending neurons in the subesophageal zone mediates aversive sensory inputs-evoked backward locomotion in Drosophila larvae

Animals typically avoid unwanted situations with stereotyped escape behavior. For instance, Drosophila larvae often escape from aversive stimuli to the head, such as mechanical stimuli and blue light irradiation, by backward locomotion. Responses to these aversive stimuli are mediated by a variety of sensory neurons including mechanosensory class III da (C3da) sensory neurons and blue-light responsive class IV da (C4da) sensory neurons and Bolwig's organ (BO). How these distinct sensory pathways evoke backward locomotion at the circuit level is still incompletely understood. Here we show that a pair of cholinergic neurons in the subesophageal zone, designated AMBs, evoke robust backward locomotion upon optogenetic activation. Anatomical and functional analysis shows that AMBs act upstream of MDNs, the command-like neurons for backward locomotion. Further functional analysis indicates that AMBs preferentially convey aversive blue light information from C4da neurons to MDNs to elicit backward locomotion, whereas aversive information from BO converges on MDNs through AMB-independent pathways. We also found that, unlike in adult flies, MDNs are dispensable for the dead end-evoked backward locomotion in larvae. Our findings thus reveal the neural circuits by which two distinct blue light-sensing pathways converge on the command-like neurons to evoke robust backward locomotion, and suggest that distinct but partially redundant neural circuits including the command-like neurons might be utilized to drive backward locomotion in response to different sensory stimuli as well as in adults and larvae.

The (Continuous) Nature of Perceived Gender Counter-Stereotype: A Threshold Model of Gender Stereotype Maintenance

People often expect men and women to look, act, and think like typical members of their gender groups. When men and women deviate from gender-stereotypical expectations across various domains, people tend to denigrate them, compared to those who follow stereotypical expectations. This derogatory attitude-termed the backlash effect-has been well supported by psychological research. However, previous studies on the backlash effect have often neglected the fact that men and women can be counter-stereotypical of their gender groups, to varying degrees. This research tried to address this continuous nature of counter-stereotypical characteristics in various domains using six experiments to evaluate individual responses to gendered facial cues, behaviors, and psychological traits. We conducted three studies, with two experiments per study. Most importantly, this research proposed a threshold model of gender stereotype maintenance to explain people's evaluations of gender-counter-stereotypical targets across various domains. The threshold model suggested that appraisal for a target with balanced gender-stereotypical and gender-counter-stereotypical characteristics tends to be more positive than for a target who strictly adheres to gender stereotypes or gender-counter-stereotypical characteristics. The results of all three studies supported the threshold model, which demonstrated a curvilinear pattern of participants' appraisals and targets' gender-counter-stereotypical degrees. The threshold model of stereotype maintenance has enriched the traditional stereotype maintenance theory and enlightened the development of a more effective impression management strategy. Moreover, it provided more ecological validity that treated gender counter-stereotype as a continuum rather than a binary variable.

Inhibition of striatal-enriched protein tyrosine phosphatase (STEP) activity reverses behavioral deficits in a rodent model of autism

Autism spectrum disorders (ASDs) are highly prevalent childhood illnesses characterized by impairments in communication, social behavior, and repetitive behaviors. Studies have found aberrant synaptic plasticity and neuronal connectivity during the early stages of brain development and have suggested that these contribute to an increased risk for ASD. STEP is a protein tyrosine phosphatase that regulates synaptic plasticity and is implicated in several cognitive disorders. Here we test the hypothesis that STEP may contribute to some of the aberrant behaviors present in the VPA-induced mouse model of ASD. In utero VPA exposure of pregnant dams results in autistic-like behavior in the pups, which is associated with a significant increase in the STEP expression in the prefrontal cortex. The elevated STEP protein levels are correlated with increased dephosphorylation of STEP substrates GluN2B, Pyk2 and ERK, suggesting upregulated STEP activity. Moreover, pharmacological inhibition of STEP rescues the sociability, repetitive and abnormal anxiety phenotypes commonly associated with ASD. These data suggest that STEP may play a role in the VPA model of ASD and STEP inhibition may have a potential therapeutic benefit in this model.

Prevalence and determinants of unconscious stereotyping among primary care physicians. An analytical cross-section study

OBJECTIVES

To explore implicit stereotyping among primary healthcare (PHC) physicians and to identify determinants of physicians' stereotyping of patients based on the patients' characteristics and appearance.

METHODS

This study followed an analytical cross-sectional design conducted between October 2019 and December 2019, and included 250 primary healthcare (PHC) physicians in Aseer Region, Kingdom of Saudi Arabia. Data was collected using a self-administered questionnaire, which included items concerning physicians' sociodemographic characteristics, and their attitudes toward patient characteristics and patient appearance.

RESULTS

Prevalence of stereotyping among PHC physicians was 63.6% with respect to patient characteristics and 57.6% with respect to patient appearance. Stereotyping based on patient characteristics was higher among younger participants, females, those with bachelor's degrees, those in general practitioner positions, and those with less experience in PHC.

CONCLUSION

Most PHC physicians in Aseer Region, Kingdom of Saudi Arabia, are liable to implicit stereotyping based on patient characteristics (namely, gender and educational level) and patient appearance (namely, clothing). Therefore, it is recommended to train PHC physicians in cultural competency to reduce unintentional acts of discrimination toward their patients.

Becoming a better parent: Mice learn sounds that improve a stereotyped maternal behavior

While mothering is often instinctive and stereotyped in species-specific ways, evolution can favor genetically "open" behavior programs that allow experience to shape infant care. Among experience-dependent maternal behavioral mechanisms, sensory learning about infants has been hard to separate from motivational changes arising from sensitization with infants. We developed a paradigm in which sensory learning of an infant-associated cue improves a stereotypical maternal behavior in female mice. Mice instinctively employed a spatial memory-based strategy when engaged repetitively in a pup search and retrieval task. However, by playing a sound from a T-maze arm to signal where a pup will be delivered for retrieval, mice learned within 7 days and retained for at least 2 weeks the ability to use this specific cue to guide a more efficient search strategy. The motivation to retrieve pups also increased with learning on average, but their correlation did not explain performance at the trial level. Bilaterally silencing auditory cortical activity significantly impaired the utilization of new strategy without changing the motivation to retrieve pups. Finally, motherhood as compared to infant-care experience alone accelerated how quickly the new sensory-based strategy was acquired, suggesting a role for the maternal hormonal state. By rigorously establishing that newly formed sensory associations can improve the performance of a natural maternal behavior, this work facilitates future studies into the neurochemical and circuit mechanisms that mediate novel sensory learning in the maternal context, as well as more learning-based mechanisms of parental behavior in rodents.

Independent acoustic variation of the higher- and lower-frequency components of biphonic calls can facilitate call recognition and social affiliation in killer whales

Each resident-type (R-type) killer whale pod has a set of stereotyped calls that are culturally transmitted from mother to offspring. The functions of particular call types are not yet clearly understood, but it is believed that calls with two independently modulated frequency components (biphonic calls) play an important role in pod communication and cohesion at long ranges. In this study we examined the possible functions of biphonic calls in R-type killer whales. First, we tested the hypothesis that the additional component enhances the potential of a call to identify the family affiliation. We found that the similarity patterns of the lower- and higher frequency components across the families were largely unrelated. Calls were classified more accurately to their respective family when both lower- and higher-frequency components were considered. Second, we tested the long-range detectability of the lower- and higher-frequency components. After adjusting the received levels by the killer whale hearing sensitivity to different frequency ranges, the sensation level of the higher-frequency component was higher than the amplitude of the lower-frequency component. Our results suggest that the higher-frequency component of killer whale biphonic calls varies independently of the lower-frequency component, which enhances the efficiency of these calls as family markers. The acoustic variation of the higher-frequency component allows the recognition of family identity of a caller even if the shape of the lower-frequency component accidentally becomes similar in unrelated families. The higher-frequency component can also facilitate family recognition when the lower-frequency component is masked by low-frequency noise.

Genetic and environmental influences on corticostriatal circuits in twins with autism

BACKGROUND

Corticostriatal circuits (CSC) have been implicated in the presentation of some restricted and repetitive behaviours (RRBs) in children with autism-spectrum disorder (ASD), and preliminary evidence suggests that disruptions in these pathways may be associated with differences in genetic and environmental influences on brain development. The objective of this investigation was to examine the impact of genetic and environmental factors on CSC regions in twins with and without ASD and to evaluate their relationship with the severity of RRBs.

METHODS

We obtained T1-weighted MRIs from same-sex monozygotic and dizygotic twin pairs, aged 6–15 years. Good-quality data were available from 48 ASD pairs (n = 96 twins; 30 pairs concordant for ASD, 15 monozygotic and 15 dizygotic; 18 pairs discordant for ASD, 4 monozygotic and 14 dizygotic) and 34 typically developing control pairs (n = 68 twins; 20 monozygotic and 14 dizygotic pairs). We generated structural measures of the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), caudate, putamen, pallidum and thalamus using FreeSurfer. Twin pair comparisons included intraclass correlation analyses and ACE modelling (a2 = additive genetics; c2 = common or shared environment; e2 = unique or nonshared environment). We also assessed correlations with RRB severity.

RESULTS

Structural variation in CSC regions was predominantly genetically mediated in typically developing twins (a2 = 0.56 to 0.87), except for ACC white matter volume (a2 = 0.42, 95% confidence interval [CI] 0.08 to 0.77). We also observed similar magnitudes of genetic influence in twins with ASD (a2 = 0.65 to 0.97), but the cortical thickness of the ACC (c2 = 0.44, 95% CI 0.22 to 0.66) and OFC (c2 = 0.60, 95% CI 0.25 to 0.95) was primarily associated with environmental factors in only twins with ASD. Twin pair differences in OFC grey matter volume were also correlated with RRB severity and were predominantly environmentally mediated.

LIMITATIONS

We obtained MRIs on 2 scanners, and analytical approaches could not identify specific genetic and environmental factors.

CONCLUSION

Genetic factors primarily contribute to structural variation in subcortical CSC regions, regardless of ASD, but environmental factors may exert a greater influence on the development of grey matter thickness in the OFC and ACC in children with ASD. The increased vulnerability of OFC grey matter to environmental influences may also mediate some heterogeneity in RRB severity in children with ASD.

Stereotypical and Actual Associations of Breast Size with Mating-Relevant Traits

Breast size varies substantially among women and influences perception of the woman by other people with regard to her attractiveness and other characteristics that are important in social contexts, including mating. The theory of sexual selection predicts that physical criteria of partner selection should be markers of the candidate's desirable properties, mainly biological quality. Few studies, however, have examined whether breast size really signals biological quality or its components and whether observers accurately interpret these signals. Our first study encompassed 163 young women and aimed to establish actual correlates of breast size. The aim of the second study was to determine preferences and stereotypes related to breast size: 252-265 women and men evaluated female digital figures varying in, among other characteristics, breast size. Breast size (breast circumference minus chest circumference) was negatively associated with body asymmetry and positively associated with infections of the respiratory system, but did not correlate with infections of the digestive system, openness to casual sex, and testosterone and estradiol level. Women and men perceived breasts in a similar way to each other: the bigger the breasts the higher the reproductive efficiency, lactational efficiency, sexual desire, and promiscuity attributed to the woman. Nevertheless, large breasts were not regarded more attractive than average ones, though small breasts were the least attractive. In addition, big-breasted women were perceived as less faithful and less intelligent than women with average or small breasts. We discuss our results from the perspectives of evolutionary psychology, perceptual biases, and social stereotypes.

Construct Validity and Cross Validity of a Test Battery Modeling Autism Spectrum Disorder (ASD) in Mice

Modeling in other organism species is one of the crucial stages in ascertaining the association between gene and psychiatric disorder. Testing Autism Spectrum Disorder (ASD) in mice is very popular but construct validity of the batteries is not available. We presented here the first factor analysis of a behavioral model of ASD-like in mice coupled with empirical validation. We defined fourteen measures aligning mouse-behavior measures with the criteria defined by DSM-5 for the diagnostic of ASD. Sixty-five mice belonging to a heterogeneous pool of genotypes were tested. Reliability coefficients vary from .68 to .81. The factor analysis resulted in a three- factor solution in line with DSM criteria: social behavior, stereotypy and narrowness of the field of interest. The empirical validation with mice sharing a haplo-insufficiency of the zinc-finger transcription factor TSHZ3/Tshz3 associated with ASD shows the discriminant power of the highly loaded items.

Neurophysiological correlates of stereotypic behaviour in a model carnivore species

Stereotypic behaviour (SB) is common in animals housed in farm, zoo or laboratory conditions, including captive Carnivora (e.g. wild ursids and felids). Neurobiological data on housing-induced SBs come from four species (macaques, two rodent species, and horses), and suggest basal ganglia (BG) dysfunction. We investigated whether similar patterns occur in Carnivora via a model, American mink, because their SB is distinctive in form and timing. We raised 32 males in non-enriched (NE) or enriched (E) cages for 2 years, and assessed two forms of SB: 1) Carnivora-typical locomotor-and-whole-body ('loco') SBs (e.g. pacing, weaving); 2) scrabbling with the forepaws. Neuronal activity was analysed via cytochrome oxidase (CO) staining of the dorsal striatum (caudate; putamen), globus pallidus (externus, GPe; internus, GPi), STN, and nucleus accumbens (NAc); and the GPe:GPi ratio (GPr) calculated to assess relative activation of direct and indirect pathways. NE mink stereotyped more, and had lower GPr CO-staining indicating relatively lower indirect pathway activation. However, no single BG area was affected by housing and nor did GPr values covary with SB. Independent of housing, elevated NAc CO-staining predicted more loco SB, while scrabbling, probably because it negatively correlated with loco SB, negatively covaried with NAc CO-staining in NE subjects. These results thus implicate the NAc in individual differences in mink SB. However, because they cannot explain why NE subjects showed more SB, they provide limited support for the BG dysfunction hypothesis for this species' housing-induced SB. More research is therefore needed to understand how barren housing causes SB in captive Carnivora.

Sex Differences in Attributions to Positive and Negative Sexual Scenarios in Men and Women With and Without Sexual Problems: Reconsidering Stereotypes

People with sexual problems are more likely to attribute negative sexual experiences to themselves, in contrast to sexually functional individuals who attribute negative sexual experiences to external factors such as the circumstance or partner. We investigated attribution patterns in 820 men and 753 women, some of whom reported an orgasmic problem, to assess differences between the sexes and those with and without an orgasmic difficulty. Specifically, using an Internet-based approach, we compared attribution responses to four sexual scenarios, one representing a positive sexual experience and three representing negative sexual experiences. Women were more likely to attribute positive outcomes to their partner than men. Women were also more likely to attribute negative outcomes to themselves than men, but they more readily blamed their partner and circumstances for negative outcomes than men as well. Those with orgasmic problems were less willing to take credit for positive outcomes and more willing to accept blame for negative outcomes. Interaction effects between sex and orgasmic problems further highlighted differences between men's and women's attribution patterns. These results are interpreted in the context of traditional notions that men's attributions tend to be more self-serving and women's attributions more self-derogatory.

Familial risk of autism alters subcortical and cerebellar brain anatomy in infants and predicts the emergence of repetitive behaviors in early childhood

Autism spectrum disorder (ASD) is a common neurodevelopmental condition, and infant siblings of children with ASD are at a higher risk of developing autistic traits or an ASD diagnosis, when compared to those with typically developing siblings. Reports of differences in brain anatomy and function in high-risk infants which predict later autistic behaviors are emerging, but although cerebellar and subcortical brain regions have been frequently implicated in ASD, no high-risk study has examined these regions. Therefore, in this study, we compared regional MRI volumes across the whole brain in 4-6-month-old infants with (high-risk, n = 24) and without (low-risk, n = 26) a sibling with ASD. Within the high-risk group, we also examined whether any regional differences observed were associated with autistic behaviors at 36 months. We found that high-risk infants had significantly larger cerebellar and subcortical volumes at 4-6-months of age, relative to low-risk infants; and that larger volumes in high-risk infants were linked to more repetitive behaviors at 36 months. Our preliminary observations require replication in longitudinal studies of larger samples. If correct, they suggest that the early subcortex and cerebellum volumes may be predictive biomarkers for childhood repetitive behaviors. Autism Res 2019, 12: 614-627. © 2019 The Authors. Autism Research published by International Society for Autism Research published byWiley Periodicals, Inc. LAY SUMMARY: Individuals with a family history of autism spectrum disorder (ASD) are at risk of ASD and related developmental difficulties. This study revealed that 4-6-month-old infants at high-risk of ASD have larger cerebellum and subcortical volumes than low-risk infants, and that larger volumes in high-risk infants are associated with more repetitive behaviors in childhood.

Cocaine differentially affects synaptic activity in memory and midbrain areas of female and male rats: an in vivo MEMRI study

Manganese enhanced magnetic resonance imaging (MEMRI) has been previously used to determine the effect of acute cocaine on calcium-dependent synaptic activity in male rats. However, there have been no MEMRI studies examining sex differences in the functional neural circuits affected by repeated cocaine. In the present study, we used MEMRI to investigate the effects of repeated cocaine on brain activation in female and male rats. Adult female and male rats were scanned at 4.7 Tesla three days after final treatment with saline, a single cocaine injection (15 mg kg^-1, i.p. × 1 day) or repeated cocaine injections (15 mg kg^-1, i.p. × 10 days). A day before imaging rats were provided with an i.p. injection of manganese chloride (70 mg kg^-1). Cocaine produced effects on MEMRI activity that were dependent on sex. In females, we observed that a single cocaine injection reduced MEMRI activity in hippocampal CA3, ventral tegmental area (VTA), and median Raphé, whereas repeated cocaine increased MEMRI activity in dentate gyrus and interpeduncular nucleus. In males, repeated cocaine reduced MEMRI activity in VTA. Overall, it appeared that female rats showed a general trend towards increase MEMRI activity with single cocaine and reduced activity with repeated exposure, while male rats showed a trend towards opposite effects. Our results provide evidence for sex differences in the in vivo neural response to cocaine, which involves primarily hippocampal, amygdala and midbrain areas.

An unexpected acoustic indicator of positive emotions in horses

Indicators of positive emotions are still scarce and many proposed behavioural markers have proven ambiguous. Studies established a link between acoustic signals and emitter’s internal state, but few related to positive emotions and still fewer considered non-vocal sounds. One of them, the snort, is shared by several perrisodactyls and has been associated to positive contexts in these species. We hypothesized that this could be also the case in horses. In this species, there is a clear need for a thorough description of non-vocal acoustic signals (snorts, snores or blows are often used interchangeably) but overall this sound produced by nostrils during expiration has up to now been mostly considered as having a hygienic function. However, observations revealed that snorts were produced more in some individuals than in others, without relationship with air conditions. We observed 48 horses living in two “extreme” conditions: restricted conditions (single stall, low roughage diet) and naturalistic conditions (stable groups in pasture). The immediate place (e.g. stall/pasture) and the behavioural/postural (behaviour performed/ears positions) contexts of snort production were observed. We additionally performed an evaluation of the welfare state, using validated behavioural (e.g. stereotypies) and postural (e.g. overall ears positions) welfare indicators. The results show that 1) snort production was significantly associated with situations known to be positive for horses (e.g. feeding in pasture) and with a positive internal state (ears in forward or sidewards positions), 2) the riding school horses produced twice as many snorts when in pasture than in stall, 3) the naturalistic population emitted significantly more snorts than riding school ones in comparable contexts, 4) the frequency of snorts was negatively correlated with the composite total chronic stress score (TCSS, reflecting compromised welfare based on the horse’s rank on the different indicators): the lower the TCSS, the higher the snort rate. Snorts therefore appear as reliable indicators of positive emotions.

Challenging behaviours at early adulthood in autism spectrum disorders: topography, risk factors and evolution

BACKGROUND

Challenging behaviours are highly prevalent in children and adolescents with autism spectrum disorders (ASD), but little is known about the prevalence and course of these behaviours during adulthood. The aims of this study were to describe the topography of challenging behaviours in a cohort of 106 young adults with ASD and to identify the risk factors for challenging behaviours. Our secondary objective was to study the changes in challenging behaviours from adolescence to early adult years.

METHOD

The present study uses data from the EpiTED prospective follow-up study in France. The presence of challenging behaviours was assessed by the Aberrant Behaviour Checklist (ABC) completed by parent informants. Several dimensions of behaviour were studied: irritability, stereotypy, lethargy, hyperactivity and self-injury. Clinical variables were collected on ASD symptom severity, cognitive and language levels, adaptive behaviours and comorbid medical disorders.

RESULTS

The presence of challenging behaviours at early adulthood was related to the young adult's cognitive and language level, ASD symptom severity and comorbid gastrointestinal and sleep disorders. The main risk factor for challenging behaviours was ASD symptom severity. The level of language impairment was a significant predictor of self-injury. Gastrointestinal disorders were a significant predictor of stereotypy. The change in behaviour topography from adolescence to early adult years corresponded with decreased parent report of hyperactivity, but no significant decrease in parent reports of irritability, stereotypy, lethargy and self-injurious behaviours.

CONCLUSIONS

The challenging behaviours in individuals with ASD persist in early adulthood and are related to core symptom severity, levels of cognitive and language impairments and medical comorbidity. The results emphasise the importance of early interventions for children with ASD to target cognitive and language abilities and to alleviate the severity of ASD symptoms. They also underscore the need to enhance opportunities for individuals with ASD to better communicate discomforts and pain in the context of medical illness.

Diazepam blocks 50 kHz ultrasonic vocalizations and stereotypies but not the increase in locomotor activity induced in rats by amphetamine

RATIONALE

We have recently shown that the benzodiazepine diazepam inhibits dopamine release in the NAc and blocks the increased release of dopamine induced by DL-amphetamine. Rewarding stimuli and many drugs of abuse can induce dopamine release in the nucleus accumbens as well as 50-kHz ultrasonic vocalizations (USVs) in rats.

OBJECTIVES

In the present study, we tested the hypothesis that diazepam can also block the increase in locomotor activity and USVs elicited by amphetamine.

METHODS

Fifty-kilohertz USVs, stereotypy, and locomotor behavior were scored in adult male Wistar rats treated with i.p. injections of saline, 3 mg/kg DL-amphetamine, 2 mg/kg diazepam, 0.2 mg/kg haloperidol, or a combination of these drugs.

RESULTS

In agreement with previous studies, amphetamine caused significant increases in the number of USV calls, stereotypies, and locomotor activity. The D2 dopamine receptor antagonist haloperidol blocked the effects of amphetamine on USVs, stereotypy, and locomotor activity. Diazepam blocked the effect of amphetamine on USV and stereotypy, but not on horizontal locomotion.

CONCLUSIONS

These results suggest that diazepam blocks the rewarding effect of amphetamine. This finding is promising for basic research regarding treatments of substance use disorders and evaluation of the impact of benzodiazepines on motivation.

Inflexible daily behaviour is associated with the ability to control an automatic reaction in autism spectrum disorder

Inflexible behaviours in people with autism spectrum disorder (ASD) broadly obstruct social communication. Meanwhile, flexibility implicates cognitive control to resolve socially conflicting situations; however, it remains unclear how people with ASD behave in the face of these conflicts in this respect. We used the ultimatum game (UG) and the implicit-association test (IAT) to examine goal-directed/economic flexibility, both of which involve conflict and cognitive control. In addition, we used the Detail and Flexibility Questionnaire (DFlex) to measure inflexible everyday behaviour with diminished cognitive control and attention shifting. We observed the decreased flexibility in participants with ASD (DFlex and IAT); further, their IAT scores positively correlated with DFlex. However, in the UG, contrary to our prediction, participants with ASD accepted unfair offers more frequently than TD. These results suggest that assessing the automatic/attention processing level with the IAT could be a useful approach to study behavioural flexibility among ASD compared with the UG, which might comprise multiple response strategies besides economic rationality. Overall, the severity of inflexible daily behaviours in people with ASD may be associated with a reduced flexible attitude at an automatic level, altered attention processing and decreased cognitive control.

Peromyscus maniculatus bairdii as a naturalistic mammalian model of obsessive-compulsive disorder: current status and future challenges

Obsessive-compulsive disorder (OCD) is a prevalent and debilitating condition, characterized by intrusive thoughts and repetitive behavior. Animal models of OCD arguably have the potential to contribute to our understanding of the condition. Deer mice (Permomyscus maniculatus bairdii) are characterized by stereotypic behavior which is reminiscent of OCD symptomology, and which may serve as a naturalistic animal model of this disorder. Moreover, a range of deer mouse repetitive behaviors may be representative of different compulsive-like phenotypes. This paper will review work on deer mouse behavior, and evaluate the extent to which this serves as a valid and useful model of OCD. We argue that findings over the past decade indicate that the deer mouse model has face, construct and predictive validity.

Measuring behavior across scales

The need for high-throughput, precise, and meaningful methods for measuring behavior has been amplified by our recent successes in measuring and manipulating neural circuitry. The largest challenges associated with moving in this direction, however, are not technical but are instead conceptual: what numbers should one put on the movements an animal is performing (or not performing)? In this review, I will describe how theoretical and data analytical ideas are interfacing with recently-developed computational and experimental methodologies to answer these questions across a variety of contexts, length scales, and time scales. I will attempt to highlight commonalities between approaches and areas where further advances are necessary to place behavior on the same quantitative footing as other scientific fields.

Repetitive behaviors in autism are linked to imbalance of corticostriatal connectivity: a functional connectivity MRI study

The neural underpinnings of repetitive behaviors (RBs) in autism spectrum disorders (ASDs), ranging from cognitive to motor characteristics, remain unknown. We assessed RB symptomatology in 50 ASD and 52 typically developing (TD) children and adolescents (ages 8-17 years), examining intrinsic functional connectivity (iFC) of corticostriatal circuitry, which is important for reward-based learning and integration of emotional, cognitive and motor processing, and considered impaired in ASDs. Connectivity analyses were performed for three functionally distinct striatal seeds (limbic, frontoparietal and motor). Functional connectivity with cortical regions of interest was assessed for corticostriatal circuit connectivity indices and ratios, testing the balance of connectivity between circuits. Results showed corticostriatal overconnectivity of limbic and frontoparietal seeds, but underconnectivity of motor seeds. Correlations with RBs were found for connectivity between the striatal motor seeds and cortical motor clusters from the whole-brain analysis, and for frontoparietal/limbic and motor/limbic connectivity ratios. Division of ASD participants into high (n = 17) and low RB subgroups (n = 19) showed reduced frontoparietal/limbic and motor/limbic circuit ratios for high RB compared to low RB and TD groups in the right hemisphere. Results suggest an association between RBs and an imbalance of corticostriatal iFC in ASD, being increased for limbic, but reduced for frontoparietal and motor circuits.

A Causal and Mediation Analysis of the Comorbidity Between Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD)

Autism spectrum disorder (ASD) and Attention-deficit/hyperactivity disorder (ADHD) are often comorbid. The purpose of this study is to explore the relationships between ASD and ADHD symptoms by applying causal modeling. We used a large phenotypic data set of 417 children with ASD and/or ADHD, 562 affected and unaffected siblings, and 414 controls, to infer a structural equation model using a causal discovery algorithm. Three distinct pathways between ASD and ADHD were identified: (1) from impulsivity to difficulties with understanding social information, (2) from hyperactivity to stereotypic, repetitive behavior, (3) a pairwise pathway between inattention, difficulties with understanding social information, and verbal IQ. These findings may inform future studies on understanding the pathophysiological mechanisms behind the overlap between ASD and ADHD.

DSM Criteria that Best Differentiate Intellectual Disability from Autism Spectrum Disorder

Clinical characteristics of autism spectrum disorder (ASD) and intellectual disability (ID) overlap, creating potential for diagnostic confusion. Diagnostic and statistical manual of mental disorders (DSM) criteria that best differentiate children with ID and some ASD features from those with comorbid ID and ASD were identified. Records-based surveillance of ASD among 8-year-old children across 14 US populations ascertained 2816 children with ID, with or without ASD. Area under the curve (AUC) was conducted to determine discriminatory power of DSM criteria. AUC analyses indicated that restricted interests or repetitive behaviors best differentiated between the two groups. A subset of 6 criteria focused on social interactions and stereotyped behaviors was most effective at differentiating the two groups (AUC of 0.923), while communication-related criteria were least discriminatory. Matching children with appropriate treatments requires differentiation between ID and ASD. Shifting to DSM-5 may improve differentiation with decreased emphasis on language-related behaviors.

Persistence and resistance to extinction in the domestic dog: Basic research and applications to canine training

This review summarizes the research investigating behavioral persistence and resistance to extinction in the dog. The first part of this paper reviews Behavioral Momentum Theory and its applications to Applied Behavior Analysis and training of pet dogs with persistent behavioral problems. I also highlight how research on Behavioral Momentum Theory can be applied to the training of detection dogs in an attempt to enhance detection performance in the presence of behavioral disruptors common in operational settings. In the second part of this review, I highlight more basic research on behavioral persistence with dogs, and how breed differences and experiences with humans as alternative sources of reinforcement can influence dogs' resistance to extinction of a target behavior. Applied Behavior Analysis and Behavior Momentum Theory have important applications for behavioral treatments to reduce the persistence of problem behavior in dogs and for the development of enhanced training methods that enhance the persistence of working dogs. Dogs can also be leveraged as natural models of stereotypic behavior and for exploring individual differences in behavioral persistence by evaluating breed and environmental variables associated with differences in canine persistance.

[CYTOKINES SECRETION BY SPLENOCY-TES IN RESPONSE TO MICE F1 (C57BL/6XDBA/2) BEHAVIOR IN ENVIRONMENTS OF VARYING COMPLEXITY]

We study the dependence of the mitogen-induced cytokine secretion by splenocytes from the character of the behavior of F1 (C57BL/6XDBA/2) mice in environments with different degrees of spatial complexity: simple in the form of home box, enriched box and maze. Suppression of in-terleukins IL-2, IL-4, IL-6 and IL-10 expression, regardless of their structural and functional properties, was observed only in an enriched environment when aggressive and neurotic manifestations were increased. The opposite effect in the form of significant increase of the productions in all studied cytokines was observed in the case of the stereotypical goal-directed behavior in a maze. It was supposed that cytokines of the splenocytes are involved in the realization of highly 307 differentiated adaptive response of the organism due to the influence of social and cognitive factors, the expression of which depends on the specific physiological and biochemical systems.

Experimentally reducing corticosterone mitigates rapid captivity effects on behavior, but not body composition, in a wild bird

Wild animals and captives display physiological and behavioral differences, and it has been hypothesized, but rarely tested, that these differences are caused by sustained elevation of the hormone corticosterone. We used repeated computed tomography (CT) imaging to examine body composition changes in breeding male and female wild house sparrows (Passer domesticus; n=20) in response to two weeks of captivity, and assessed behavioral changes using video recordings. Half of the birds received the drug mitotane, which significantly decreased stress-induced corticosterone titers compared to controls. Based on the CT images, fat volumes increased, and pectoralis muscle density and heart and testes volumes decreased, over the two weeks of captivity in both groups of birds. However, beak-wiping, a behavior that can indicate anxiety and aggression, showed increased occurrence in controls compared to mitotane-treated birds. While our results do not support the hypothesis that these body composition changes were primarily driven by stress-induced corticosterone, our data suggest that experimentally reducing stress-induced corticosterone may mitigate some captivity-induced behavioral changes. Broadly, our results emphasize that researchers should take behavioral and physiological differences between free-living animals and captives into consideration when designing studies and interpreting results. Further, time in captivity should be minimized when birds will be reintroduced back to the wild.

What worries parents of a child with Autism? Evidence from a biomarker for chronic stress

BACKGROUND

Previous studies have reported correlations between various aspects of the behaviour and symptomatology of children with Autism Spectrum Disorder (ASD) and their parents' self-reports of stress via standardised scales.

AIMS

To extend that literature, a physiological index of parental chronic stress was used instead of their self-reports-dysregulation of the Diurnal Rhythm (DR) of the Hypothalamic-Pituitary-Adrenal (HPA) axis.

METHODS

A sample of 149 parents of a child with ASD provided salivary cortisol at the predicted time of daily maximum cortisol concentration and at a time of daily lower concentration. Adherence to the predicted DR was assessed via a dichotomous (present/not-present) as well as a continuous measure, and MANOVA and linear regression were used to detect significant associations between ASD-related variables in their children and parents' DR.

RESULTS

Identified only a single significant correlate of DR dysregulation in both statistical procedures-Self-Injurious Behaviour (SIB) exhibited by their child and observed by the parents.

CONCLUSIONS AND IMPLICATIONS

These findings extend previous data using self-report indices of parental stress and should be included in parent-support settings to alert parents to the long-term health effects of the stress they experience in regard to their child's SIB.

Sex differences in psychotomimetic-induced behaviours in rats

Animal model studies using equal numbers of males and females are sparse in psychiatry research. Given the marked sex differences observed in psychiatric disorders, such as schizophrenia, using both males and females in research studies is an important requirement. Thus the aim of this study was to examine sex differences in psychotomimetic-induced behavioural deficits relevant to psychosis. We therefore compared the acute effect of amphetamine or phencyclidine on locomotor activity and prepulse inhibition in adult male and female Sprague-Dawley rats. The results of this study were that: (1) amphetamine-induced distance travelled was greater in female rats than in male rats, (2) phencyclidine-induced locomotor hyperactivity was similar in male and female rats; (3) there were no sex differences in amphetamine- or phencyclidine-induced disruption of prepulse inhibition; (4) male rats had an increased startle response after amphetamine. These findings suggest that sensitivity to amphetamine, but not phencyclidine, differs between male and female rats, and that this sex difference is selective to locomotor hyperactivity and startle, but not prepulse inhibition. This study used two widely-used, validated preclinical assays relevant to psychosis; the results of this study have implications for psychiatry research, particularly for disorders where marked sex differences in onset and symptomology are observed.

Stereotypical Escape Behavior in Caenorhabditis elegans Allows Quantification of Effective Heat Stimulus Level

A goal of many sensorimotor studies is to quantify the stimulus-behavioral response relation for specific organisms and specific sensory stimuli. This is especially important to do in the context of painful stimuli since most animals in these studies cannot easily communicate to us their perceived levels of such noxious stimuli. Thus progress on studies of nociception and pain-like responses in animal models depends crucially on our ability to quantitatively and objectively infer the sensed levels of these stimuli from animal behaviors. Here we develop a quantitative model to infer the perceived level of heat stimulus from the stereotyped escape response of individual nematodes Caenorhabditis elegans stimulated by an IR laser. The model provides a method for quantification of analgesic-like effects of chemical stimuli or genetic mutations in C. elegans. We test ibuprofen-treated worms and a TRPV (transient receptor potential) mutant, and we show that the perception of heat stimuli for the ibuprofen treated worms is lower than the wild-type. At the same time, our model shows that the mutant changes the worm’s behavior beyond affecting the thermal sensory system. Finally, we determine the stimulus level that best distinguishes the analgesic-like effects and the minimum number of worms that allow for a statistically significant identification of these effects.

A doctor assesses pain by asking her patient to “rate your pain on the scale of 1 to 10.” She may then prescribe some drugs and later ask the question again to see if they worked. New drugs are often developed using animal models, but we cannot ask an animal, especially a small invertebrate animal, to rate, similarly, the strength of its perceived noxious stimulus. In this paper, we successfully develop computational tools that read the “body language” of a roundworm C. elegans to estimate the strength of the heat stimulus that it experiences. Unlike previous attempts that have focused on ad hoc selected components of the overall behavior, our approach is based on quantifying the complete time series of the escape behavior, which we show to be captured by a behavioral “template” that scales in response to the stimulus strength. The existence of this template allows us to solve one of the hard questions in pain research: disambiguating analgesic-like effects of drugs or genetic perturbations from their other effects on animal behavior.

Problem behaviour in adolescent boys with fragile X syndrome: relative prevalence, frequency and severity

BACKGROUND

A large proportion of boys with fragile X syndrome (FXS), the most common known inherited form of intellectual disability (ID), exhibit problem behaviours (e.g. aggression, self-injury, property destruction and stereotypy) that can negatively impact the health and safety of others as well as the individual concerned. However, data are limited concerning the relative prevalence, frequency and severity of problem behaviours exhibited by boys with FXS compared with those by boys with mixed-aetiology ID who also exhibit problem behaviours.

METHOD

As part of a larger study on problem behaviour, we obtained survey data on 85 adolescent boys with FXS and 155 age-matched boys with mixed-aetiology ID who exhibited at least one form of problem behaviour.

RESULTS

For boys with FXS, stereotypy was reported to be more prevalent (χ²  = 4.52, P = 0.012), self-injury was reported to more frequent (U = 2525, P = 0.010) and aggression was reported to be less severe (U = 4176, P = 0.029) than for boys with mixed-aetiology ID. Ratings of aggression and property destruction were highly correlated in each group in terms of both frequency and severity (r = 0.60 to 0.71). Examination of the data by age indicated that the relative frequency of self-injury decreased with age in boys with FXS (χ²  = 8.29, P = 0.040).

CONCLUSIONS

Taken together, these results refine and extend previous studies concerning the specificity of the behavioural phenotype in FXS and indicate that specific forms of problem behaviour shown by boys with FXS appear to differ from those exhibited by boys with mixed-aetiology ID in terms of prevalence, frequency and severity. Studies employing more objective measures of frequency and severity, including direct observations, are needed to confirm these findings.

Restricted vs. unrestricted wheel running in mice: Effects on brain, behavior and endocannabinoids

Beneficial effects of voluntary wheel running on hippocampal neurogenesis, morphology and hippocampal-dependent behavior have widely been studied in rodents, but also serious side effects and similarities to stereotypy have been reported. Some mouse strains run excessively when equipped with running wheels, complicating the comparability to human exercise regimes. Here, we investigated how exercise restriction to 6h/day affects hippocampal morphology and metabolism, stereotypic and basal behaviors, as well as the endocannabinoid system in wheel running C57BL/6 mice; the strain most commonly used for behavioral analyses and psychiatric disease models. Restricted and unrestricted wheel running had similar effects on immature hippocampal neuron numbers, thermoregulatory nest building and basal home-cage behaviors. Surprisingly, hippocampal gray matter volume, assessed with magnetic resonance (MR) imaging at 9.4 Tesla, was only increased in unrestricted but not in restricted runners. Moreover, unrestricted runners showed less stereotypic behavior than restricted runners did. However, after blockage of running wheels for 24h stereotypic behavior also increased in unrestricted runners, arguing against a long-term effect of wheel running on stereotypic behavior. Stereotypic behaviors correlated with frontal glutamate and glucose levels assessed by ¹H-MR spectroscopy. While acute running increased plasma levels of the endocannabinoid anandamide in former studies in mice and humans, we found an inverse correlation of anandamide with the daily running distance after long-term running. In conclusion, although there are some diverging effects of restricted and unrestricted running on brain and behavior, restricted running does not per se seem to be a better animal model for aerobic exercise in mice.

The Days and Nights of Zoo Elephants: Using Epidemiology to Better Understand Stereotypic Behavior of African Elephants (Loxodonta africana) and Asian Elephants (Elephas maximus) in North American Zoos

Stereotypic behavior is an important indicator of compromised welfare. Zoo elephants are documented to perform stereotypic behavior, but the factors that contribute to performance have not been systematically assessed. We collected behavioral data on 89 elephants (47 African [Loxodonta africana], 42 Asian [Elephas maximus]) at 39 North American zoos during the summer and winter. Elephants were videoed for a median of 12 daytime hours per season. A subset of 32 elephants (19 African, 13 Asian) was also observed live for a median of 10.5 nighttime hours. Percentages of visible behavior scans were calculated from five minute instantaneous samples. Stereotypic behavior was the second most commonly performed behavior (after feeding), making up 15.5% of observations during the daytime and 24.8% at nighttime. Negative binomial regression models fitted with generalized estimating equations were used to determine which social, housing, management, life history, and demographic variables were associated with daytime and nighttime stereotypic behavior rates. Species was a significant risk factor in both models, with Asian elephants at greater risk (daytime: p<0.001, Risk Ratio = 4.087; nighttime: p<0.001, Risk Ratio = 8.015). For both species, spending time housed separately (p<0.001, Risk Ratio = 1.009), and having experienced inter-zoo transfers (p<0.001, Risk Ratio = 1.175), increased the risk of performing higher rates of stereotypy during the day, while spending more time with juvenile elephants (p<0.001, Risk Ratio = 0.985), and engaging with zoo staff reduced this risk (p = 0.018, Risk Ratio = 0.988). At night, spending more time in environments with both indoor and outdoor areas (p = 0.013, Risk Ratio = 0.987) and in larger social groups (p = 0.039, Risk Ratio = 0.752) corresponded with reduced risk of performing higher rates of stereotypy, while having experienced inter-zoo transfers (p = 0.033, Risk Ratio = 1.115) increased this risk. Overall, our results indicate that factors related to the social environment are most influential in predicting elephant stereotypic behavior rates.

Walking Behavior of Zoo Elephants: Associations between GPS-Measured Daily Walking Distances and Environmental Factors, Social Factors, and Welfare Indicators

Research with humans and other animals suggests that walking benefits physical health. Perhaps because these links have been demonstrated in other species, it has been suggested that walking is important to elephant welfare, and that zoo elephant exhibits should be designed to allow for more walking. Our study is the first to address this suggestion empirically by measuring the mean daily walking distance of elephants in North American zoos, determining the factors that are associated with variations in walking distance, and testing for associations between walking and welfare indicators. We used anklets equipped with GPS data loggers to measure outdoor daily walking distance in 56 adult female African (n = 33) and Asian (n = 23) elephants housed in 30 North American zoos. We collected 259 days of data and determined associations between distance walked and social, housing, management, and demographic factors. Elephants walked an average of 5.3 km/day with no significant difference between species. In our multivariable model, more diverse feeding regimens were correlated with increased walking, and elephants who were fed on a temporally unpredictable feeding schedule walked 1.29 km/day more than elephants fed on a predictable schedule. Distance walked was also positively correlated with an increase in the number of social groupings and negatively correlated with age. We found a small but significant negative correlation between distance walked and nighttime Space Experience, but no other associations between walking distances and exhibit size were found. Finally, distance walked was not related to health or behavioral outcomes including foot health, joint health, body condition, and the performance of stereotypic behavior, suggesting that more research is necessary to determine explicitly how differences in walking may impact elephant welfare.

Black Pete through the Eyes of Dutch Children

The traditional figure of Black Pete seen during the December festivities around Sinterklaas (the Dutch Santa Claus) in the Netherlands has sparked fierce debates about his racial stereotypical characteristics and his potentially negative effects on children’s opinions about black people. The Black Pete phenomenon has even been discussed by the United Nations Committee on the Elimination of Racial Discrimination, resulting in a report urging the Netherlands to eliminate this form of racial stereotyping. The adult debate about Black Pete is clearly important, but Sinterklaas is essentially a children’s holiday. Surprisingly, there have never been any systematic studies to examine children’s views on Black Pete. The current study is the first to do so. In a sample of 201 children aged 5–7 years, we collected free descriptions of Black Pete, asked children to group him in relation to other figures, and to assign characteristics to him and comparison figures. The results showed that (1) Children are clearly aware of Black Pete’s skin color and subordinate status; (2) Children associate Black Pete more with clowns than with black people; (3) Children evaluate Black Pete very positively, but the positive characteristics do not generalize to their evaluation of black people. The findings illustrate the deep-rooted childhood origins of many Dutch people’s affection for Black Pete and their lack of awareness of his relation to racial stereotypes. This explains the resistance to changing the Black Pete figure and the slowness of the change process on this front.

Adolescent Maturation of Dopamine D1 and D2 Receptor Function and Interactions in Rodents

Adolescence is a developmental period characterized by heightened vulnerability to illicit drug use and the onset of neuropsychiatric disorders. These clinical phenomena likely share common neurobiological substrates, as mesocorticolimbic dopamine systems actively mature during this period. Whereas prior studies have examined age-dependent changes in dopamine receptor binding, there have been fewer functional analyses. The aim of the present study was therefore to determine whether the functional consequences of D1 and D2-like activation are age-dependent. Adolescent and adult rats were given direct D1 and D2 agonists, alone and in combination. Locomotor and stereotypic behaviors were measured, and brains were collected for analysis of mRNA expression for the immediate early genes (IEGs), cfos and arc. Adolescents showed enhanced D2-like receptor control of locomotor and repetitive behaviors, which transitioned to dominant D1-like mechanisms in adulthood. When low doses of agonists were co-administered, adults showed supra-additive behavioral responses to D1/D2 combinations, whereas adolescents did not, which may suggest age differences in D1/D2 synergy. D1/D2-stimulated IEG expression was particularly prominent in the bed nucleus of the stria terminalis (BNST). Given the BNST’s function as an integrator of corticostriatal, hippocampal, and stress-related circuitry, and the importance of neural network dynamics in producing behavior, an exploratory functional network analysis of regional IEG expression was performed. This data-driven analysis demonstrated similar developmental trajectories as those described in humans and suggested that dopaminergic drugs alter forebrain coordinated gene expression age dependently. D1/D2 recruitment of stress nuclei into functional networks was associated with low behavioral output in adolescents. Network analysis presents a novel tool to assess pharmacological action, and highlights critical developmental changes in functional neural circuitry. Immature D1/D2 interactions in adolescents may underlie their unique responses to drugs of abuse and vulnerability to psychopathology. These data highlight the need for age-specific pharmacotherapy design and clinical application in adolescence.

Characterising repetitive behaviours in young boys with fragile X syndrome

BACKGROUND

Repetitive behaviours are frequently observed in individuals with intellectual disability (ID). The present study examined the profile, inter-correlations and predictive correlates of repetitive behaviours in boys with fragile X syndrome (FXS), the leading inherited cause of ID. Specific child characteristics examined as predictors included anxiety, nonverbal cognition and autism social-affective symptomatology.

METHOD

Participants were 39 boys with FXS (aged 6-10 years). Repetitive behaviours were measured using the Repetitive Behavior Scale - Revised (RBS-R) - a 43-item caregiver-report measure normed on individuals with ID.

RESULTS

Restricted Interests and Sensory Motor behaviours were reported as most problematic for this sample of boys, whereas Self-injurious behaviours were less problematic. All subscales of the RBS-R were significantly inter-correlated. Nonverbal IQ was negatively related, whereas anxiety and social affective symptoms of autism spectrum disorder were positively related, to scores for Restricted Interests. Anxiety was also positively related to scores for Compulsive behaviours and Ritualistic Sameness behaviours.

CONCLUSIONS

This study provides a preliminary description of repetitive behaviours in boys with FXS, which may form the groundwork for future research.

How does environmental enrichment reduce repetitive motor behaviors? Neuronal activation and dendritic morphology in the indirect basal ganglia pathway of a mouse model

Repetitive motor behaviors are observed in many neurodevelopmental and neurological disorders (e.g., autism spectrum disorders, Tourette syndrome, fronto-temporal dementia). Despite their clinical importance, the neurobiology underlying these highly stereotyped, apparently functionless behaviors is poorly understood. Identification of mechanisms that mediate the development of repetitive behaviors will aid in the discovery of new therapeutic targets and treatment development. Using a deer mouse model, we have shown that decreased indirect basal ganglia pathway activity is associated with high levels of repetitive behavior. Environmental enrichment (EE) markedly attenuates the development of such aberrant behaviors in mice, although mechanisms driving this effect are unknown. We hypothesized that EE would reduce repetitive motor behaviors by increasing indirect basal ganglia pathway function. We assessed neuronal activation and dendritic spine density in basal ganglia of adult deer mice reared in EE and standard housing. Significant increases in neuronal activation and dendritic spine densities were observed only in the subthalamic nucleus (STN) and globus pallidus (GP), and only for those mice that exhibited an EE-induced decrease in repetitive motor behavior. As the STN and GP lie within the indirect pathway, these data suggest that EE-induced attenuation of repetitive motor behaviors is associated with increased functional activation of the indirect basal ganglia pathway. These results are consistent with our other findings highlighting the importance of the indirect pathway in mediating repetitive motor behaviors.

Situational and Age-Dependent Decision Making during Life Threatening Distress in Myotis macrodactylus

Echolocation and audiovocal communication have been studied extensively in bats. The manner in which these abilities are incorporated within escape behaviors during life-threatening distress is largely unknown. Here we tested the hypothesis that behavioral response profiles expressed during distress are relatively stereotypic given their evolutionary adaptations to avoid predators. We subjected juvenile and adult big-footed myotis (Myotis macrodactylus) to a sequence of three types of life threatening distress: 1) trapping them in a mist-net (environmental threat), 2) approaching them when trapped (predator threat), and 3) partially restraining their freedom to move (arrest), and recorded their escape behavior in each of the three conditions. Response profiles differed across individuals and with the context in which they were expressed. During environmental and predator threat, bats displayed significantly more biting and wing-flapping behaviors and emitted more echolocation pulses than during arrest. Response profiles also varied with age. During arrest, juveniles were more likely than adults to emit distress calls and vice-versa for biting and wing flapping during environmental and predator threat. Overall, individualized response profiles were classified into ten clusters that were aligned along two divergent response trajectories when viewed within two-dimensional, multifactorial decision space. Juvenile behaviors tended to follow a predominantly "social-dependence" trajectory, whereas adult behaviors were mostly aligned along a "self-reliance" trajectory. We conclude that bats modify their vocal behavior and make age-appropriate and contextually adaptive decisions when distressed. This decision-making ability is consistent with observations in other social species, including humans.