Altered Grooming Cycles in Transgenic Drosophila

Head grooming in Drosophila consists of repeated sweeps of the legs across the head, comprising regular cycles. We used the GAL4-UAS system to study the effects of overexpressing shibirets1 and of Adar knockdown via RNA interference, on the period of head-grooming cycles in Drosophila. Overexpressing shibirets1 interferes with synaptic vesicle recycling and thus with cell communication, while Adar knockdown reduces RNA editing of neuronal transcripts for a large number of genes. All transgenic flies and their controls were tested at 22° to avoid temperature effects; in wild type, cycle frequency varied with temperature with a Q10 of 1.3. Two experiments were performed with transgenic shibirets1: (1) each fly was heat-shocked for 10 min at 30° immediately before testing at 22° and (2) flies were not heat shocked. In both experiments, cycle period was increased when shibirets1 was overexpressed in all neurons, but was not increased when shibirets1 was overexpressed in motoneurons alone. We hypothesize that grooming cycles in flies overexpressing shibirets1 are lengthened because of synaptic impairment in neural circuits that control head-grooming cycles. In flies with constitutive, pan-neuronal Adar knockdown, cycle period was more variable within individuals, but mean cycle period was not significantly altered. We conclude that RNA editing is essential for the maintenance of within-individual stereotypy of head-grooming cycles.

Repetitive Behaviors in Dogs

Repetitive behaviors in companion animals have been compared with obsessive-compulsive disorders in people. There is evidence that repetitive behaviors may go unrecognized because they have a high level of comorbidity with other, more salient, behavior problems and may be overshadowed or regarded as amusing eccentricities. To assess repetitive behavior problems, we propose a standardized approach involving 5 categories or axes. This approach aims to identify the nature of the problem and the balance among medical, environmental, and temperamental factors. Environmental modification, behavioral modification, and drug treatment are discussed.

B cell receptor immunoglobulin stereotypy in chronic lymphocytic leukemia: Key to understanding disease biology and stratifying patients

Sequence convergence, otherwise stereotypy, of B cell receptor immunoglobulin (BcR IG) from unrelated patients is a distinctive feature of the IG gene repertoire in chronic lymphocytic leukemia (CLL) whereby patients expressing a particular BcR IG archetype are classified into groups termed stereotyped subsets. From a biological perspective, the fact that a considerable fraction (∼41%) of patients with CLL express (quasi)identical or stereotyped BcR IG underscores the key role of antigen selection in the natural history of CLL. From a clinical perspective, at odds with the pronounced heterogeneity of CLL at large, patients belonging to the same stereotyped subset display consistent clinical presentation and outcome, including response to treatment, likely as a reflection of consistent biological background. Many major stereotyped subsets were recently shown to have satellites, that is, smaller subsets that are immunogenetically similar. Preliminary evidence supports that this similarity extends to shared biological and even clinical features, with important implications for patient stratification. Consequently, BcR IG stereotypy emerges as a powerful tool for dissecting the heterogeneity of CLL toward refined risk stratification and, eventually, more precise therapeutic interventions.

Influence of the dose of ketamine used on schizophrenia-like symptoms in mice: A correlation study with TH, GAD67, and PPAR-γ

Schizophrenia is a chronic, debilitating mental illness that has not yet been completely understood. In this study, we aimed to investigate the effects of different doses of ketamine, a non-competitive NMDA receptor antagonist, on the positive- and negative-like symptoms of schizophrenia. We also explored whether these effects are related to changes in the immunoreactivity of GAD67, TH, and PPAR-γ in brain structures. To conduct the study, male mice received ketamine (20-40 mg/kg) or its vehicle (0.9 % NaCl) intraperitoneally for 14 consecutive days. We quantified stereotyped behavior, the time of immobility in the forced swimming test (FST), and locomotor activity after 7 or 14 days. In addition, we performed ex vivo analysis of the immunoreactivity of GAD, TH, and PPAR-γ, in brain tissues after 14 days. The results showed that ketamine administration for 14 days increased the grooming time in the nose region at all tested doses. It also increased immobility in the FST at 30 mg/kg doses and decreased the number of rearing cycles during stereotyped behavior at 40 mg/kg. These behavioral effects were not associated with changes in locomotor activity. We did not observe any significant alterations regarding the immunoreactivity of brain proteins. However, we found that GAD and TH were positively correlated with the number of rearing during the stereotyped behavior at doses of 20 and 30 mg/kg ketamine, respectively. GAD was positively correlated with the number of rearing in the open field test at a dose of 20 mg/kg. TH was inversely correlated with immobility time in the FST at a dose of 30 mg/kg. PPAR-γ was inversely correlated with the number of bouts of stereotyped behavior at a dose of 40 mg/kg of ketamine. In conclusion, the behavioral alterations induced by ketamine in positive-like symptoms were reproduced with all doses tested and appear to depend on the modulatory effects of TH, GAD, and PPAR-γ. Conversely, negative-like symptoms were associated with a specific dose of ketamine.

Effects of Complex Feeding Enrichment on the Behavior of Captive Malayan Sun Bears (Helarctos malayanus)

All zoos grapple with challenges of keeping captive animals engaged in natural behaviors, especially for bears which prove to be among the more challenging species to keep stimulated. In captivity, a common indicator of poor welfare is the presence of stereotypic behaviors. This study tests whether providing complex feeding enrichment devices decreases the duration of stereotypic behavior and increases enrichment interaction for three adult female sun bears (Helarctos malayanus) at Oakland Zoo in California. This study uses two different enrichment devices presented at three complexity levels. After three weeks of baseline data collection when no complex enrichment is present, the complex enrichment is introduced three times a week per level over six weeks. Sun bear interaction with the enrichment devices is also measured to examine the effect of complexity on enrichment use. Providing complex enrichment decreased the duration of stereotypic behavior when compared to baseline. Across the six weeks, the duration of stereotypic behavior is significantly less on the complex enrichment days compared to non-complex enrichment days. The complex enrichment has variable effects on enrichment use. These results suggest that providing complex enrichment may have a positive influence on the behavior of captive bears.

The dopaminergic D1 receptor modulates the hyperactivity of Bapa mutant mice

The mutant bate-palmas ("claps"; symbol - bapa) mice induced by the mutagenic chemical ENU present motor incoordination and postural alterations. A previous study showed that bapa mice present increased motor/exploratory behaviors during the prepubertal period due to increased striatal tyrosine hydroxylase expression, suggesting striatal dopaminergic system hyperactivity. This study aimed to evaluate the involvement of striatal dopaminergic receptors in the hyperactivity of bapa mice. Male bapa mice and their wild strain (WT) were used. Spontaneous motor behavior was observed in the open-field test, and stereotypy was evaluated after apomorphine administration. The effects of DR1 and DR2 dopaminergic antagonists (SCH-23,390; sulpiride) and the striatal DR1 and D2 receptor gene expression were evaluated. Relative to WT, bapa mice showed: 1) increased general activity for four days; 2) increased rearing and sniffing behavior and decreased immobility after apomorphine; 3) blockage of rearing behavior after the DR2 antagonist but no effect after DR1 antagonist; 4) blockage of sniffing behavior after the DR1 antagonist in bapa and WT mice but no effect after the DR2 antagonist; 5) increased immobility after the DR1 antagonist but no effect after the DR2 antagonist; 6) increased expression of striatal DR1 receptor gene and reduced the DR2 expression gene after apomorphine administration. Bapa mice showed increased activity in open field behavior. The increased rearing behavior induced by apomorphine of bapa mice resulted from the increased gene expression of the DR1 receptor.

Associations between nesting, stereotypy, and working memory in deer mice: response to levetiracetam

BACKGROUND

Some deer mice (Peromyscus maniculatus bairdii) exhibit various phenotypes of persistent behaviors. It remains unknown if and how said phenotypes associate with early-life and adult cognitive perturbations, and whether potentially cognitive enhancing drugs might modify such associations. Here, we explored the longitudinal relationship between early-life behavioral flexibility and the expression of persistent behavior in adulthood. We also investigated how said phenotypes might associate with working memory in adulthood, and how this association might respond to chronic exposure to the putative cognitive enhancer, levetiracetam (LEV).

METHODS

76 juvenile deer mice were assessed for habit-proneness in the Barnes maze (BM) and divided into two exposure groups (n = 37-39 per group), i.e., control and LEV (75 mg/kg/day). After 56 days of uninterrupted exposure, mice were screened for nesting and stereotypical behavior, and then assessed for working memory in the T-maze.

RESULTS

Juvenile deer mice overwhelmingly utilize habit-like response strategies, regardless of LNB and HS behavior in adulthood. Further, LNB and HS are unrelated in terms of their expression, while LEV reduces the expression of LNB, but bolsters CR (but not VA). Last, an increased level of control over high stereotypical expression may facilitate improved working memory performance.

CONCLUSION

LNB, VA and CR, are divergent in terms of their neurocognitive underpinnings. Chronic LEV administration throughout the entire rearing period may be of benefit to some phenotypes, e.g., LNB, but not others (CR). We also show that an increased level of control over the expression of stereotypy may facilitate improved working memory performance.

The Effects of a Teacher-Implemented Video-Enhanced Activity Schedule Intervention on the Mathematical Skills and Collateral Behaviors of Students with Autism

This study used a multiple probe design to evaluate the effects of a teacher-implemented video-schedule intervention on the mathematical skills and untargeted challenging behaviors of five elementary-school students with autism. Results indicated that the intervention was effective in improving participants' academic performance, and a decrease in the level of challenging behaviors and stereotypy was observed for participants following the introduction of intervention. Additionally, academic gains generalized across academic problems and to a small group setting, suggesting that this technology-based intervention is an efficient use of instructional time. Future research targeting a variety of academic skills and examining intervention implementation by additional practitioners (e.g., teaching assistants) is warranted.

Genetic Analysis of the Stereotypic Phenotype in Peromyscus maniculatus (deer mice)

Peromyscus maniculatus, including the laboratory stock BW, have been used as a model organism for autism spectrum disorder and obsessive-compulsive disorder because of the high occurrence of stereotypy. Several studies have identified neurological and environmental components of the phenotype; however, the heritability of the phenotype has not been examined. This study characterizes the incidence and heritability of vertical jumping stereotypy (VS) and backflipping (BF) behavior in the BW stock of the Peromyscus Genetic Stock Center, which are indicative of autism spectrum disorders. In addition, interspecies crosses between P. maniculatus and P. polionotus were also performed to further dissect genetically stereotypic behavior. The inheritance pattern of VS suggests that multiple genes result in a quantitative trait with low VS being dominant over high VS. The inheritance pattern of BF suggests that fewer genes are involved, with one allele causing BF in a dominant fashion. An association analysis in BW could reveal the underlying genetic loci associated with stereotypy in P. maniculatus, especially for the BF behavior.

Exploring Subtypes of Repetitive Behavior in Children with Autism Through Functional Analysis and Wearable Technology: a Pilot Biobehavioral Assessment

Objectives

Prior research has established assessment methodologies, such as functional analysis to identify specific contexts in which restricted and repetitive behavior (RRB) occurs, and measures of heart rate variability (HRV) to index the level of autonomic arousal in individuals with autism spectrum disorder (ASD). Yet, a gap remains in integrating multiple assessment methodologies to examine the complex underlying mechanisms of RRB. This study piloted a multi-disciplinary approach to assess both the functional behavioral and neurophysiological factors that may underlie occurrences of RRB. The study (a) evaluated the effect of a modified functional analysis protocol on delineating functional subtypes of RRB and (b) explored the effect of using a wearable technology within a functional analysis on identifying the relationship between RRB and HRV.

Method

A single-case alternating treatment design was used to randomly alternate noncontingent low-stimulation and high-stimulation conditions in a modified functional analysis protocol. Simultaneous measurement of RRB and HRV was obtained through direct behavioral observations and a wristband that collects blood volume pulse, respectively. Visual analysis of time series data was used to determine the functional subtypes of RRB, and nonparametric correlational analyses were conducted to determine the association between HRV and RRB.

Results

Findings from a sample of six participants suggest preliminary effectiveness of the assessment protocol in identifying subtypes of RRB and a significant correlation between HRV and RRB.

Conclusions

This study demonstrates the potential effect and usability of a wearable technology-aided biobehavioral approach to assess RRB and HRV in individuals with ASD.

Repetitive Behavior Scale for Early Childhood (RBS-EC): Psychometrics and Developmental Effects with a Community Sample

Restricted, repetitive behaviors and interests (RRBIs) occur commonly in young children in the course of typical development, but too frequent or persistent RRBIs have been linked to a variety of psychosocial and neurodevelopmental disorders. Unfortunately, a lack of psychometrically sound, feasible instruments stymies RRBI study and intervention in early childhood. Therefore, this study validated an extant RRBI measure (i.e., Repetitive Behavior Scale for Early Childhood; RBS-EC) for predominately neurotypical community children ages 2-7 years via an MTurk survey of 300 caregivers. Confirmatory factor analyses best supported a 4-factor model for the RBS-EC (i.e., repetitive motor, rituals and routines, restricted interests, self-directed behaviors). RBS-EC scores varied significantly with age and gender; namely, RRBIs were typically (1) less frequent but more problematic with older versus younger children and (2) more frequent and problematic with boys versus girls. Findings extend the RBS-EC's utility in RRBI assessment and treatment during early childhood.

Descriptive Longitudinal Analysis of Stereotypy and Corresponding Changes in Psychotropic Medication

INTRODUCTION

Psychotropic medication is often prescribed to individuals with intellectual and developmental disabilities who engage in challenging and other behavior (e.g., aggression and stereotypy, respectively), but there is limited understanding of the effects of these medications on behavior.

OBJECTIVE

Within the context of a larger study that evaluated the effects of psychotropic medication regimen changes on the presentation of challenging behavior, this study describes the presentation of stereotypic behavior of three individuals diagnosed with autism spectrum disorder.

METHODS

Stereotypy was measured during weekly, one-hour, direct observations and during the control and ignore conditions of functional analyses of challenging behavior (which were conducted following changes in psychotropic medication regimens).

RESULTS

Patterns of stereotypy varied over time, but not significantly, and at times seemed to coincide with medication changes.

DISCUSSION

Our results suggest stereotypy persists throughout adulthood; however, additional research is needed.

Benefits of a ketogenic diet on repetitive motor behavior in mice

Repetitive motor behaviors are repetitive and invariant movements with no apparent function, and are common in several neurological and neurodevelopmental disorders, including autism spectrum disorders (ASD). However, the neuropathology associated with the expression of these abnormal stereotypic movements is not well understood, and effective treatments are lacking. The ketogenic diet (KD) has been used for almost a century to treat intractable epilepsy and, more recently, disorders associated with inflexibility of behavioral routines. Here, we show a novel application for KD to reduce an abnormal repetitive circling behavior in a rodent model. We then explore potential mediation through the striatum, as dysregulation of cortico-basal ganglia circuitry has previously been implicated in repetitive motor behavior. In Experiments 1 and 2, adult FVB mice were assessed for levels of repetitive circling across a 3-week baseline period. Mice were then switched to KD and repetitive circling was assessed for an additional 3 weeks. In Experiment 1, time on KD was associated with reduced repetitive behavior. In Experiment 2, we replicated these benefits of KD and assessed dendritic spine density in the striatum as one potential mechanism for reducing repetitive behavior, which yielded no differences. In Experiment 3, adult female circling mice were given a single administration of a dopamine D2 receptor antagonist (L-741,646) that was associated with reduced repetitive behavior over time. Future research will explore the relationship between KD and dopamine within basal ganglia nuclei that may be influencing the benefits of KD on repetitive behavior.

Parent-reported measure of repetitive behavior in Phelan-McDermid syndrome

Background

Phelan McDermid syndrome (PMS) is a neurogenetic condition associated with a high prevalence of intellectual disability (ID) and autism spectrum disorder (ASD). This study provides a more comprehensive and quantitative profile of repetitive behaviors within the context of ID seen with the condition.

Methods

Individuals age 3–21 years with a confirmed PMS diagnosis participated in a multicenter observational study evaluating the phenotype and natural history of the disorder. We evaluated data collected from this study pertaining to repetitive behaviors from the Repetitive Behavior Scales-Revised (RBS-R).

Results

There were n = 90 participants who were part of this analysis. Forty-seven percent (n = 42/90) were female, and the average age at baseline evaluation was 8.88 ± 4.72 years. The mean best estimate IQ of the cohort was 26.08 ± 17.67 (range = 3.4–88), with n = 8 with mild ID (or no ID), n = 20 with moderate ID, and n = 62 with severe-profound ID. The RBS-R total overall score was 16.46 ± 13.9 (compared to 33.14 ± 20.60 reported in previous studies of ASD) (Lam and Aman, 2007), and the total number of items endorsed was 10.40 ± 6.81 (range = 0–29). After statistical correction for multiple comparisons, IQ correlated with the RBS-R stereotypic behavior subscale score (r_s = − 0.33, unadjusted p = 0.0014, adjusted p = 0.01) and RBS-R stereotypic behavior total number of endorsed items (r_s = − 0.32, unadjusted p = 0.0019, adjusted p = 0.01). IQ did not correlate with any other RBS-R subscale scores.

Conclusions

The RBS-R total overall score in a PMS cohort appears milder compared to individuals with ASD characterized in previous studies. Stereotypic behavior in PMS may reflect cognitive functioning.

The Role of the Cerebellum in Repetitive Behavior Across Species: Childhood Stereotypies and Deer Mice

Recent studies suggest that the cerebellum may have a significant role in repetitive behaviors. In primary complex motor stereotypies, typically developing children have repetitive movements usually involving rhythmic flapping/waving arm/hand movements. Similarly, the deer mouse animal model exhibits inherited repetitive behaviors, with increased frequencies of spontaneous jumping and rearing. In this study, data from both children with motor stereotypies and deer mice were used to investigate the role of the cerebellum in repetitive behaviors. The 3.0-T MRI volumetric imaging of the cerebellum was obtained in 20 children with primary complex motor stereotypies and 20 healthy controls. In deer mice, cerebellar volume (n = 7/group) and cell counts (n = 9/group) were compared between high- and low-activity animals. Levels of cerebellar neurotransmitters were also determined via HPLC (n = 10/group). In children with stereotypies, (a) there were a statistically significant reduction (compared to controls) in the white matter volume of the posterior cerebellar lobule VI-VII that negatively correlated with motor control and (b) an 8% increase in the anterior vermis gray matter that positively correlated with motor Stereotypy Severity Scores (SSS). In deer mice, (a) there was a significant increase in the volume of the anterior vermal granular cell layer that was associated with higher activity and (b) dentate nucleus cell counts were higher in high activity animals. Similar increases in volume were observed in anterior vermis in children with stereotypies and a deer mouse model of repetitive behaviors. These preliminary findings support the need for further investigation of the cerebellum in repetitive behaviors.

CalDAG-GEFI mediates striatal cholinergic modulation of dendritic excitability, synaptic plasticity and psychomotor behaviors

CalDAG-GEFI (CDGI) is a protein highly enriched in the striatum, particularly in the principal spiny projection neurons (SPNs). CDGI is strongly down-regulated in two hyperkinetic conditions related to striatal dysfunction: Huntington’s disease and levodopa-induced dyskinesia in Parkinson’s disease. We demonstrate that genetic deletion of CDGI in mice disrupts dendritic, but not somatic, M1 muscarinic receptors (M1Rs) signaling in indirect pathway SPNs. Loss of CDGI reduced temporal integration of excitatory postsynaptic potentials at dendritic glutamatergic synapses and impaired the induction of activity-dependent long-term potentiation. CDGI deletion selectively increased psychostimulant-induced repetitive behaviors, disrupted sequence learning, and eliminated M1R blockade of cocaine self-administration. These findings place CDGI as a major, but previously unrecognized, mediator of cholinergic signaling in the striatum. The effects of CDGI deletion on the self-administration of drugs of abuse and its marked alterations in hyperkinetic extrapyramidal disorders highlight CDGI’s therapeutic potential.

Implication of the social function of excessive self-grooming behavior in BTBR T+ltpr3tf/J mice as an idiopathic model of autism

Autism spectrum disorder (ASD) is defined by two core behavioral characteristics, namely, restricted repetitive behaviors and impaired social-communicative functioning. BTBR T⁺ltpr3^tf/J (BTBR) mice provide a valuable animal model for ASD to elucidate the underlying mechanisms of these two behavioral characteristics of ASD. This study examined the social function of excessive grooming behavior in BTBR mice as a phenotype of restricted repetitive behaviors. Compared to the control C57BL/6 J (B6) strain, BTBR mice showed increased self-grooming when placed alone in a test apparatus, and this behavior was even more evident when confronted with a stimulus mouse (either B6 or BTBR) in a three-chamber test apparatus. While B6 mice tended to groom their face/snout region on the empty side of the chamber, BTBR mice showed excessive grooming with frequent transitions among grooming body regions on the side of the chamber containing a social stimulus. Acute systemic injection of buspirone,a serotonin 1A receptor agonist, as an anxiolytic, facilitated approach behavior toward social stimuli in the three-chamber setting in both B6 and BTBR mice. However, this treatment did not affect grooming behavior in B6 mice and significantly enhanced self-grooming in BTBR mice. These behaviors in BTBR mice suggest a potential signaling function of grooming in response to social stimuli, in which bodywide grooming of BTBR mice expressed in the proximity of social opponents may stimulate the release of olfactory (possibly dismissive) signals. Consequently, the putative neural mechanisms underlying excessive grooming may differ from those regulating social approaches that are associated with anxiolytic mechanisms.

Brief Report: Mobile Technology to Support Parents in Reducing Stereotypy

Although behavioral interventions have been known to effectively reduce stereotypy in children with ASD, these types of interventions are not accessible to all families. In response to this issue, we evaluated the effects of the iSTIM, an iOS application designed to support parents in the reduction of stereotypy in their child with ASD. We used a series of AB designs to determine the effectiveness of the iSTIM on stereotypy using parents as behavior change agents. The use of iSTIM by the parents led to a reduction in stereotypy for six of seven participants. Our results suggest that the use of technology may be a cost effective and easily accessible method for parents to reduce stereotypy in their child with ASD.

Stereotypy with Parkinsonism as a Rare Sequelae of Dengue Encephalitis: A Case Report and Literature Review

Background

Parkinsonism following viral encephalitis is well reported. However, in addition, to parkinsonism other movement disorders such as dystonia, chorea, myoclonus may also be observed in these patients. Stereotypy is a very rare manifestation following viral encephalitis.

Case report

Here we report a rare case of a 25-year-old young man who developed stereotypy and parkinsonism following dengue virus encephalitis. The stereotypy was in the form of snapping of fingers of left-hand which was repetitive, purposeless, non-goal directed, present for most of the day and partially suppressible.

Discussion

This report expands the spectrum of movement disorders seen in dengue infection.

The Significance of B-cell Receptor Stereotypy in Chronic Lymphocytic Leukemia: Biological and Clinical Implications

The finding that (quasi)identical, stereotyped B-cell receptor (BcR) immunoglobulins IGs) are expressed in a significant fraction of chronic lymphocytic leukemia (CLL) highlighted the importance of antigen selection in disease pathogenesis. Subsets of patients sharing the same stereotyped BcR IG display consistent biological features and, at least for certain subsets, clinical presentation and outcome, including the response to particular treatment. On these grounds, BcR IG stereotypy emerges as a useful tool for dissecting the pronounced heterogeneity of CLL toward refining risk stratification and therapeutic management aligned with the principles of precision medicine.

Repetitive Thoughts and Repetitive Behaviors in Williams Syndrome

The purpose of the study was to characterize repetitive phenomena in Williams syndrome (WS). The parents of 60 subjects with WS completed the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) or Children's Y-BOCS, the Yale Global Tic Severity Scale, the Stereotyped Behavior Scale, and the Spence Children's Anxiety Scale-Parent Version. Nineteen males and 41 females participated in the study. Six subjects (10%) had obsessions only, six (10%) had compulsions only, and eleven (18%) had at least one obsession and at least one compulsion. None of the subjects had tics. Fifty subjects (83.3%) endorsed at least one stereotypy. Increased anxiety was associated with increased severity of obsessions, but not severity of compulsions or stereotypies.

Volumetric magnetic resonance and diffusion tensor imaging of C58/J mice: neural correlates of repetitive behavior

Restricted, repetitive behavior (RRB) involves sequences of responding with little variability and no obvious function. RRB is diagnostic for autism spectrum disorder (ASD) and a significant feature in several neurodevelopmental disorders. Despite its clinical importance, relatively little is known about how RRB is mediated by broader neural circuits. In this study, we employed ultra-high field (17.6 Tesla) magnetic resonance imaging (MRI) to study the C58/J mouse model of RRB. We determined alterations in brain morphology and connectivity of C58/J mice and their relationship to repetitive motor behavior using structural MRI and diffusion tensor imaging (DTI). Compared to the genetically similar C57BL/6 control mouse strain, C58/J mice showed evidence of structural alterations in basal ganglia and cerebellar networks. In particular, C58/J mice exhibited reduced volumes of key cortical and basal ganglia regions that have been implicated in repetitive behavior, including motor cortex, striatum, globus pallidus, and subthalamic nucleus, as well as volume differences in the cerebellum. Moreover, DTI revealed differences in fractional anisotropy and axial diffusivity in cerebellar white matter of C58/J mice. Importantly, we found that RRB exhibited by C58/J mice was correlated with volume of the striatum, subthalamic nucleus, and crus II of the cerebellum. These regions are key nodes in circuits connecting the basal ganglia and cerebellum and our findings implicate their role in RRB, particularly the indirect pathway.

Audience Control and the Emission of Stereotypy and Social Verbal Exchanges in Children With Autism and Developmental Disabilities

In 2 experiments, using a within-subjects alternating-conditions design, we measured our participants' stereotypic and verbal behavior under 2 audience conditions. Our participants were 8 children, ages 10 and 11 years, diagnosed with autism and related developmental disabilities. We measured the percentage of intervals with occurrences of stereotypy (Experiment 1) and the number of verbal operants emitted per minute (Experiment 2) in the presence of 2 types of audiences: members of the participants' own special education class and typically developing peers from general education classes. Results from both experiments demonstrated that participants emitted a lower percentage of intervals with stereotypy and higher rates of social verbal operants in the presence of their typically developing peers than in their self-contained special education classrooms.

Sleep and stereotypy in children with autism: effectiveness of function-based behavioral treatment

OBJECTIVES

Children with autism spectrum disorder (ASD) experience high rates of sleep problems, which exacerbate the core symptoms of ASD, including stereotypy (restricted and repetitive behaviors). Conversely, stereotypy can interfere with sleep by actively competing with sleep-facilitative behaviors (eg, lying down quietly). Behavioral interventions informed by functional behavioral assessment (FBA) significantly reduce sleep problems in children with ASD, however, their impact on sleep-interfering stereotypy is not clear. This study investigated the effectiveness of function-based behavioral treatments for sleep problems, including sleep-interfering stereotypy, in children with ASD, the maintenance of these effects, and parents' satisfaction with the treatment process.

METHODS

A non-concurrent multiple baselines across participants design was used to evaluate the effectiveness of function-based, individualized treatments for sleep problems and sleep-interfering stereotypy in three children with ASD. For each participant, stereotypy was automatically maintained and interfered with the initiation and/or re-initiation of sleep. Parents implemented multi-component treatments that included a faded bedtime procedure.

RESULTS

Treatment reduced sleep problems in 2/3 participants, and the duration of stereotypy was reduced in all participants. Treatment effects were largely maintained at follow-up, and parent-reported satisfaction was high.

CONCLUSION

These results support prior research demonstrating the effectiveness of FBA-informed behavioral treatments for sleep problems in children with ASD. Further, this study shows that these treatments may be effective in reducing sleep-interfering stereotypy. Future research should more thoroughly investigate the bidirectional relationships between sleep and core symptoms of ASD, and address how these relationships are assessed and treated in the sleep context.

Nestlet Shredding and Nest Building Tests to Assess Features of Psychiatric Disorders in Mice

Mimicking the various facets of human psychiatric and neurodevelopmental disorders in animal models is a challenging task. Nevertheless, mice have emerged as a widely used model system to study pathophysiology and treatment strategies for these diseases. However, the corresponding behavioral tests are often elaborate and require extensive experience in behavioral testing. Here, we present protocols for two simple assays, nest building and nestlet shredding, that can serve as a starting point for the behavioral phenotyping of mouse models with (potential) features of psychiatric disorders. Both tests have been reported previously and we extend prior descriptions by including adaptations and refinements derived from our practical experience, like the use of the home cage instead of a fresh cage for nestlet shredding. Summarized, we provide ready-to-use protocols for two behavioral assays that allow the generation of robust data with minimal time and cost expenditure and enable an initial assessment of features of psychiatric or neurodevelopmental disorders in mouse models of these diseases.

An Investigation of Functional Communication Training and Schedule Thinning Using a Multiple Schedule on Elopement to Access Stereotypy

Individuals diagnosed with autism spectrum disorder (ASD) who engage in stereotypy may also emit a prior, temporally contiguous, high-risk response to access stereotypic behaviors. For example, the participant in this study who was diagnosed with ASD engaged in a chained response that included elopement, often in unsafe locations, to access light switch flipping. Previous research indicates that functional communication training (FCT) with delay fading is a viable approach to reduce chained problem behavior. In this study, we extended previous research by (a) evaluating the generalized effect of FCT and schedule thinning using multiple schedule technology for an automatically maintained chained response, and (b) evaluating whether intervention effects maintained in the participant's optimal context. Results for the participant suggested that FCT with schedule thinning mitigated high-risk chained responding across settings and discrimination training using a multiple schedule assessment effectively signaled available and unavailable times for the participant to emit the chained response which matched the participant's natural schedule parameters.

Dietary glutamate and the brain: In the footprints of a Jekyll and Hyde molecule

Glutamate is a crucial neurotransmitter of the mammalian central nervous system, a molecular component of our diet, and a popular food-additive. However, for decades, concerns have been raised about the issue of glutamate's safety as a food additive; especially, with regards to its ability (or otherwise) to cross the blood-brain barrier, cause excitotoxicity, or lead to neuron death. Results of animal studies following glutamate administration via different routes suggest that an array of effects can be observed. While some of the changes appear deleterious, some are not fully-understood, and the impact of others might even be beneficial. These observations suggest that with regards to the mammalian brain, exogenous glutamate might exert a double-sided effect, and in essence be a two-faced molecule whose effects may be dependent on several factors. This review draws from the research experiences of the authors and other researchers regarding the effects of exogenous glutamate on the brain of rodents. We also highlight the possible implications of such effects on the brain, in health and disease. Finally, we deduce that beyond the culinary effects of exogenous glutamate, there is the possibility of a beneficial role in the understanding and management of brain disorders.

Intermittent access cocaine self-administration produces psychomotor sensitization: effects of withdrawal, sex and cross-sensitization

RATIONALE

With repeated administration, the psychomotor activating effects of drugs such as cocaine or amphetamine can change in very different ways-showing sensitization or tolerance-depending on whether they are administered more or less intermittently. This behavioral plasticity is thought to reflect, at least in part, changes in dopamine (DA) neurotransmission, and therefore, may provide insights into the development of substance use disorders. Indeed, the most widely used preclinical model of cocaine addiction, which involves Long Access (LgA) self-administration procedures, is reported to produce tolerance to cocaine's psychomotor activating effects and effects on DA activity. In contrast, Intermittent Access (IntA) cocaine self-administration is more effective than LgA in producing addiction-like behavior, but sensitizes DA neurotransmission. There is, however, very little information concerning the effects of IntA experience on the psychomotor activating effects of cocaine.

OBJECTIVE

The objective of this study was to determine whether IntA experience produces psychomotor sensitization with similar characteristics to that produced by the intermittent, noncontingent administration of cocaine.

RESULTS

IntA to cocaine did indeed produce psychomotor sensitization that (1) was greater after a long (30 days) vs. short (1 day) period of withdrawal, (2) was greater in females than males, and (3) resulted in cross-sensitization to another psychomotor stimulant drug, amphetamine.

CONCLUSION

The tolerance sometimes associated with LgA cocaine self-administration has been cited in support of the idea that, in addiction, drug-seeking and drug-taking is motivated to overcome a DA deficiency and associated anhedonia. In contrast, the neurobehavioral sensitization associated with IntA cocaine self-administration favors an incentive-sensitization view.

Effects of personality and rearing-history on the welfare of captive Asiatic lions (Panthera leo persica)

Background

The long-term success of ex-situ conservation programmes depends on species-appropriate husbandry and enrichment practices complemented by an accurate welfare assessment protocol. Zoos and conservation breeding programmes should employ a bottom-up approach to account for intraspecific variations in measures of animal welfare. We studied 35 (14:21) captive Asiatic lions in Sakkarbaug Zoological Garden, Junagadh, India to understand the implications of individual variations on welfare measures. We categorized the subjects based on personality traits (bold or shy), rearing history (wild-rescued or captive-raised), sex, and social-grouping. We explored the association of these categorical variables on welfare indices such as behavioural diversity, latency to approach novel objects, enclosure usage and aberrant repetitive behaviours. Further, we assessed the inter-relationships between different behavioural measures of welfare.

Results

Our results show that intraspecific variations based on rearing-history and personality traits are significantly associated with the welfare states of captive Asiatic lions. Asiatic lions with bold personality traits (M = 0.50, SD = 0.12, N = 21) and those raised in captivity (M = 0.47, SD = 0.12, N = 16) used enclosure space more homogenously compared to shy (M = 0.71, SD = 0.15, N = 14) and wild-rescued (M = 0.67, SD = 0.15, N = 19) animals. Behaviour diversity was significantly higher in captive-raised (M = 1.26, SD = 0.3, N = 16) and bold (M = 1.23, SD = 0.26, N = 21) subjects compared to wild-rescued (M = 0.83, SD = 0.35, N = 19) and shy (M = 0.73, SD = 0.34, N = 14) individuals. Aberrant repetitive behaviours (stereotypy) were significantly lower in bold (M = 7.01, SD = 4, N = 21) and captive-raised (M = 7.74, SD = 5.3) individuals compared to wild-rescued (M = 13.12, SD = 6.25, N = 19) and shy (M = 16.13, SD = 5.4, N = 16) lions. Sex and social-grouping of subjects did not show significant associations with behavioural welfare indices. Interestingly, behaviour diversity was reliably predicted by the enclosure usage patterns and aberrant repetitive behaviours displayed by subjects.

Discussion

Our findings underline the importance of individual-centric, behaviour-based, and multi-dimensional welfare assessment approaches in ex-situ conservation programmes. The results suggest that behavioural welfare indices complemented with individual variations can explain inter-individual differences in behavioural welfare measure outcomes of Asiatic lions. These findings also provide zoo managers with a non-invasive tool to reliably assess and improve husbandry practices for Asiatic lions. Understanding the unique welfare requirement of individuals in captivity will be crucial for the survival of the species.

Locomotor effects of 3,4-methylenedioxymethamphetamine (MDMA) and its deuterated form in mice: psychostimulant effects, stereotypy, and sensitization

RATIONALE

There is a renewed interest in the use of 3,4-methylenedioxymethamphetamine (MDMA) for treating psychiatric conditions. Although MDMA has entered phase II clinical trials and shows promise as an adjunct treatment, there is an extensive literature detailing the potential neurotoxicity and adverse neurobehavioral effects associated with MDMA use. Previous research indicates that the adverse effects of MDMA may be due to its metabolism into reactive catechols that can enter the brain and serve directly as neurotoxicants. One approach to mitigate MDMA's potential for adverse effects is to reduce O-demethylation by deuterating the methylenedioxy ring of MDMA. There are no studies that have evaluated the effects of deuterating MDMA on behavioral outcomes.

OBJECTIVES

The purpose of the present study was to assess the motor-stimulant effects of deuterated MDMA (d2-MDMA) and compare them to MDMA in male mice.

METHODS

Two experiments were performed to quantify mouse locomotor activity and to vary the drug administration regimen (single bolus administration or cumulative administration).

RESULTS

The results of Experiments 1 and 2 indicate that d2-MDMA is less effective at eliciting horizontal locomotion than MDMA; however, the differences between the compounds diminish as the number of cumulative administrations increase. Both d2-MDMA and MDMA can elicit sensitized responses, and these effects cross-sensitize to the prototypical drug of abuse methamphetamine. Thus, d2-MDMA functions as a locomotor stimulant similar to MDMA, but, depending on the dosing regimen, may be less susceptible to inducing sensitization to stereotyped movements.

CONCLUSIONS

These findings indicate that d2-MDMA is behaviorally active and produces locomotor effects that are similar to MDMA, which warrant additional assessments of d2-MDMA's behavioral and physiological effects to determine the conditions under which this compound may serve as a relatively safer alternative to MDMA for clinical use.

Blue Light Covers Increase Stereotypy and Decrease On-Task Behavior for Students with Autism

Some recommended strategies for individuals with autism spectrum disorder (ASD) are not empirically based. The purpose of the study was to evaluate effects of blue light covers on levels of stereotypy and on-task behavior. Four male children with ASD who engaged in repetitive behavior participated. Placing light covers over the classroom's fluorescent lights relative to normal classroom lighting did not improve on-task behavior or stereotypy.

Interventions for Repetitive Behavior in Young Children with Autism: A Survey of Behavioral Practices

Children with autism spectrum disorder (ASD) display social-communication deficits and present with rigid and repetitive patterns of behavior and/or interests (RRBIs). Compared to interventions for social-communication skills, less attention has been given to RRBIs, especially with regard to interventions for young children. We surveyed 128 behavior analysts who implemented interventions for young children with ASD on their use of 16 practices and one assessment for the treatment of RRBIs. The majority of our sample perceived the practices to be effective in producing sustainable behavior change. Behavior analysts generally responded in the same way to items about reinforcement-based practices, punishment-based practices, and a group of commonly packaged antecedent and consequence-based package components. Implications and future directions are discussed.

Visual feedback during motor performance is associated with increased complexity and adaptability of motor and neural output

Complex motor behavior is believed to be dependent on sensorimotor integration - the neural process of using sensory input to plan, guide, and correct movements. Previous studies have shown that the complexity of motor output is low when sensory feedback is withheld during precision motor tasks. However, much of this research has focused on motor behavior rather than neural processing, and therefore, has not specifically assessed the role of sensorimotor neural functioning in the execution of complex motor behavior. The present study uses a stimulus-tracking task with simultaneous electroencephalography (EEG) recording to assess the effect of visual feedback on motor performance, motor complexity, and sensorimotor neural processing in healthy adults. The complexity of the EEG signal was analyzed to capture the information content in frequency bands (alpha and beta) and scalp regions (central, parietal, and occipital) that are associated with sensorimotor processing. Consistent with previous literature, motor performance and its complexity were higher when visual feedback was provided relative to when it was withheld. The complexity of the neural signal was also higher when visual feedback was provided. This was most robust at frequency bands (alpha and beta) and scalp regions (parietal and occipital) associated with sensorimotor processing. The findings show that visual feedback increases the information available to the brain when generating complex, adaptive motor output.

Behavioural responses to video and live presentations of females reveal a dissociation between performance and motivational aspects of birdsong

Understanding the regulation of social behavioural expression requires insight into motivational and performance aspects. While a number of studies have independently assessed these aspects of social behaviours, few have examined how they relate to each other. By comparing behavioural variation in response to live or video presentations of conspecific females, we analysed how variation in the motivation to produce courtship song covaries with variation in performance aspects of courtship song in male zebra finches (Taeniopygia guttata). In agreement with previous reports, we observed that male zebra finches were less motivated to produce courtship songs to videos of females than to live presentations of females. However, we found that acoustic features that reflect song performance were not significantly different between songs produced in response to videos of females, and those produced in response to live females. For example, songs directed at video presentations of females were just as fast and stereotyped as songs directed at live females. These experimental manipulations and correlational analyses reveal a dissociation between motivational and performance aspects of birdsong and suggest a refinement of neural models of song production and control. In addition, they support the efficacy of videos to study both motivational and performance aspects of social behaviours.

Developmental modulation and predictability of age-dependent vocal plasticity in adult zebra finches

Predicting the nature of behavioral plasticity can provide insight into mechanisms of behavioral expression and control. Songbirds like the zebra finch rely on vocal signals for communication, and the performance of these signals demonstrate considerable plasticity over development. Traditionally, these signals were thought to be fixed in adulthood, but recent studies have revealed significant age-dependent changes to spectral and temporal features of song in adult songbirds. A number of age-dependent changes to song resemble acute changes to adult song performance across social contexts (e.g., when an adult male sings to a female relative to when he sings in isolation). The ability of variation in social context-dependent changes to predict variation in age-dependent plasticity would suggest shared mechanisms, but little is known about this predictability. In addition, although developmental experiences can shape adult plasticity, little is known about the extent to which social interactions during development affect age-dependent change to adult song. To this end, we systematically analyzed age- and context-dependent changes to adult zebra finch song, and then examined the degree to which age-dependent changes varied across birds that were social or non-socially tutored birds and to which social context-dependent changes predicted age-dependent changes. Non-socially tutored birds showed more dramatic changes to the broad structure of their motif over time than socially tutored birds, but non-socially and socially tutored birds did not differ in the extent of changes to various spectral and temporal features of song. Overall, we found that adult zebra finches produced longer and more spectrally stereotyped songs when they were older than when they were younger. Moreover, regardless of developmental tutoring, individual variation in age-dependent changes to song bout duration and syllable repetition were predicted by variation in social context-dependent changes to these features. These data indicate that social experiences during development can shape some aspects of adult plasticity and that acute context-dependent and long-term age-dependent changes to some song features could be mediated by modifications within similar neural substrates.

Abnormal repetitive behaviors in zebrafish and their relevance to human brain disorders

Abnormal repetitive behaviors (ARBs) are a prominent symptom of numerous human brain disorders and are commonly seen in rodent models as well. While rodent studies of ARBs continue to dominate the field, mounting evidence suggests that zebrafish (Danio rerio) also display ARB-like phenotypes and may therefore be a novel model organism for ARB research. In addition to clear practical research advantages as a model species, zebrafish share high genetic and physiological homology to humans and rodents, including multiple ARB-related genes and robust behaviors relevant to ARB. Here, we discuss a wide spectrum of stereotypic repetitive behaviors in zebrafish, data on their genetic and pharmacological modulation, and the overall translational relevance of fish ARBs to modeling human brain disorders. Overall, the zebrafish is rapidly emerging as a new promising model to study ARBs and their underlying mechanisms.

Effects of Intraperitoneal N-methyl-D-aspartate (NMDA) Administration on Nociceptive/Repetitive Behaviors in Juvenile Mice

Dysregulation of excitatory neurotransmission has been implicated in the pathogenesis of neuropsychiatric disorders. Pharmacological inhibition of N-methyl-D-aspartate (NMDA) receptors is widely used to model neurobehavioral pathologies and underlying mechanisms. There is ample evidence that overstimulation of NMDA-dependent neurotransmission may induce neurobehavioral abnormalities, such as repetitive behaviors and hypersensitization to nociception and cognitive disruption, pharmacological modeling using NMDA has been limited due to the induction of neurotoxicity and blood brain barrier breakdown, especially in young animals. In this study, we examined the effects of intraperitoneal NMDA-administration on nociceptive and repetitive behaviors in ICR mice. Intraperitoneal injection of NMDA induced repetitive grooming and tail biting/licking behaviors in a dose- and age-dependent manner. Nociceptive and repetitive behaviors were more prominent in juvenile mice than adult mice. We did not observe extensive blood brain barrier breakdown or neuronal cell death after peritoneal injection of NMDA, indicating limited neurotoxic effects despite a significant increase in NMDA concentration in the cerebrospinal fluid. These findings suggest that the observed behavioral changes were not mediated by general NMDA toxicity. In the hot plate test, we found that the latency of paw licking and jumping decreased in the NMDA-exposed mice especially in the 75 mg/kg group, suggesting increased nociceptive sensitivity in NMDA-treated animals. Repetitive behaviors and increased pain sensitivity are often comorbid in psychiatric disorders (e.g., autism spectrum disorder). Therefore, the behavioral characteristics of intraperitoneal NMDA-administered mice described herein may be valuable for studying the mechanisms underlying relevant disorders and screening candidate therapeutic molecules.

A ketogenic diet diminishes behavioral responses to cocaine in young adult male and female rats

Ketogenic diets (KDs) are high fat, low carbohydrate formulations traditionally used to treat epilepsy; more recently, KDs have shown promise for a wide range of other neurological disorders. Drug addiction studies suggest that repeated exposure to drugs of abuse, including cocaine, results in a suite of neurobiological changes that includes neuroinflammation, decreased glucose metabolism, and disordered neurotransmission. Given that KDs positively regulate these factors, we addressed whether administration of a KD has potential as a novel therapy for drug addiction. In this study, male and female Sprague-Dawley rats were placed on a KD or a control diet (CD), beginning at five weeks of age and continuing through the end of behavioral testing. Three weeks after initiation of dietary treatments, rats received daily i.p. injections of cocaine (15 mg/kg) or saline vehicle for one week, were drug free for a subsequent week, and then all animals received a final challenge injection of 15 mg/kg cocaine. In the absence of cocaine injections, stereotyped locomotor responses were minimal and were unaffected by dietary treatment. In contrast, both males and females fed a KD exhibited decreased cocaine-induced stereotyped responses as compared to CD-fed rats. The sensitization of ambulatory responses was also disrupted in KD-fed rats. These results suggest that KDs directly impact dopamine-mediated behaviors, and hence may hold potential as a therapy for drug addiction.

Immunoglobulin Gene Analysis in Chronic Lymphocytic Leukemia

The formation of B-cell receptor immunoglobulin (BcR IG) is the result of a multi-step process that starts at the pro-B cell stage with the VDJ gene recombination of IG genes of the heavy chain, followed by VJ recombination of the light chain genes at the pre-B II cell stage. As a result, a fully functional BcR IG is expressed on the surface of any given naive B cell. After antigen encounter, somatic hypermutation (SHM) and class-switch recombination (CSR) act on the rearranged IG genes within the context of affinity maturation, leading to the expression of a BcR IG with unique immunogenetic and functional characteristics. Since B-cell neoplasms arise from the transformation of a single B cell, this renders IG gene rearrangements ideal clonal markers as they will be identical in all neoplastic cells of each individual clone. Furthermore, the rearranged IG sequence can also serve as a cell development/maturation marker, given that its configuration is tightly linked to specific B-cell developmental stages. Finally, in certain instances, as in the case of chronic lymphocytic leukemia (CLL), the clonotypic IG sequence and, more specifically, the load of somatic hypermutations within the rearranged IG heavy variable (IGHV) gene, holds prognostic and potentially predictive value. However, in order to take full advantage of the information provided from the analysis of the clonotypic IG gene rearrangement sequences, robust methods and tools need to be applied. Here, we provide details regarding the methodologies necessary to ensure reliable IG sequence analysis based on the recognized expertise of the European Research initiative on CLL (ERIC). All methodological and analytical steps are described below, starting from the isolation of blood mononuclear cells (PBMC), moving to the identification of the clonotypic IG rearrangement and ending with the accurate interpretation of the SHM status.

Stereotyped B Cell Receptor Immunoglobulins in B Cell Lymphomas

Comprehensive analysis of the clonotypic B cell receptor immunoglobulin (BcR IG) gene rearrangement sequences in patients with mature B cell neoplasms has led to the identification of significant repertoire restrictions, culminating in the discovery of subsets of patients expressing highly similar, stereotyped BcR IG. This finding strongly supports selection by common epitopes or classes of structurally similar epitopes in the ontogeny of these tumors. BcR IG stereotypy was initially described in chronic lymphocytic leukemia (CLL), where the stereotyped fraction of the disease accounts for a remarkable one-third of patients. However, subsequent studies showed that stereotyped BcR IG are also present in other neoplasms of mature B cells, including mantle cell lymphoma (MCL) and splenic marginal zone lymphoma (SMZL). Subsequent cross-entity comparisons led to the conclusion that stereotyped IG are mostly "disease-specific," implicating distinct immunopathogenetic processes. Interestingly, mounting evidence suggests that a molecular subclassification of lymphomas based on BcR IG stereotypy is biologically and clinically relevant. Indeed, particularly in CLL, patients assigned to the same subset due to expressing a particular stereotyped BcR IG display remarkably consistent biological background and clinical course, at least for major and well-studied subsets. Thus, the robust assignment to stereotyped subsets may assist in the identification of mechanisms underlying disease onset and progression, while also refining risk stratification. In this book chapter, we provide an overview of the recent BcR IG stereotypy studies in mature B cell malignancies and outline previous and current methodological approaches used for the identification of stereotyped IG.

Stress and Ketamine, Bimodal Influence on Cognitive Functions

The glutamate N-methyl-D-aspartate receptor (NMDAR) non-selective antagonist, ketamine, has been recently repurposed as a rapidly acting antidepressant, catalyzing the vigorous investigation of glutamate-signaling modulators as novel therapeutic agents for depressive disorders. Beneficial effects of this drug in the quick-acting treatment of depression are recognized. The long-term effects of ketamine have not been known, including the cognitive sphere. It is well acknowledged that prolonged exposure to stress induces depression and cognitive impairment. It seemed reasonable to ask how the long-term ketamine administration would affect stressed animals in the aspect of cognitive functions. In the current study we tested whether it is possible for ketamine, used in prolonged-regimen in rats, to alleviate stress-evoked memory deficits? Stressed (restraint 2 h daily for 21 days) and non-stressed rats (6-weeks-old) were treated with ketamine for 21 days and next subjected to a battery of behavioral tests: for the assessment of working and reference spatial memory (Morris water maze (MWM) and Barnes maze (BM)), stereotypy (stereotypy test - ST), locomotor functions (Open field - OF) and anxiety behavior (Elevated plus maze - EPM). Ketamine administration resulted in a significant stereotype behaviour in rats tested in ST. Stressed rats displayed a significant decline in the spatial working and reference memory. The effect of chronic ketamine administration depended on the type of test and differed between control rats and animals simultaneously exposed to chronic stress. However, in the MWM the impact was quite unequivocal, as we observed an improvement in spatial memory in stressed animals and a deterioration in non-stressed animals after ketamine administration. In the BM, the effect of ketamine changed in successive attempts, from favorable in the initial period to negative at the end of the test in the group of stressed animals and without a significant impact on control animals. We found no significant effects of ketamine on locomotor performance and on the level of anxiety. Taken together, these findings demonstrate that ketamine potently abolishes or prevents some kinds of stress-induced memory impairments and cognitive decline in rats, although in some circumstances, it could even increase damage to memory, especially in unstressed animals. It seems that the prolonged use of ketamine in the prevention of stress-induced memory declines can fulfill its role.

Experimental analysis of stereotypy with applications of nonparametric statistical tests for alternating treatments designs

INTRODUCTION

Stereotypy is common in individuals with developmental disabilities and may become disruptive in the context of instruction.

PURPOSE

The purpose of this study was to embed brief experimental analyses in the context of reading instruction to evaluate effects of antecedent and consequent variables on latencies to and durations of stereotypy.

METHOD

We trained a reading instructor to implement a trial-based functional analysis and a subsequent antecedent analysis of stimulus features for an adolescent with autism in a reading clinic. We used alternating treatments designs with applications of nonparametric statistical analyses to control Type I error rates.

RESULTS

Results of the experimental analyses suggested stereotypy was maintained by non-social reinforcement and informed the extent to which features of academic materials influenced levels of stereotypy. Results of nonparametric statistical analyses were consistent with conclusions based on visual analysis.

CONCLUSION

Brief experimental analyses may be embedded in academic instruction to inform the stimulus conditions that influence stereotypy.

Hypomania in Bobble-Head Doll Syndrome: A Case Report of Surgically Treated Stereotypy and Hypomania

A 22-year-old man was admitted with gradually aggravating stereotypic head movement with hypomania. Brain magnetic resonance imaging showed a large suprasellar arachnoid cyst extending into the third ventricle, with obstructive hydrocephalus, characteristic of bobble-head doll syndrome. Endoscopic fenestration of the suprasellar arachnoid cyst was performed. Stereotypic head movement stopped immediately after surgery and hypomanic symptoms gradually improved within a month. During 4 years of follow-up observation without medication, neuropsychiatric symptoms did not relapse. We report our experience of surgically treating stereotypy and hypomania in a case of bobble-head doll syndrome and discuss the possible neuropsychiatric mechanisms of this rare disease.

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.

Flexibility of feeding movements in pigs: effects of changes in food toughness and stiffness on the timing of jaw movements

In mammals, chewing movements can be modified, or flexible, in response to changes in food properties. Variability between and within food in the temporal characteristics of chewing movements can impact chewing frequency and rhythmicity, which in turn may affect food breakdown, energy expenditure and tooth wear. Here, we compared total chewing cycle duration and intra-cycle phase durations in pigs chewing on three foods varying in toughness and stiffness: apples (low toughness, low stiffness), carrots (high toughness, low stiffness), and almonds (high toughness, high stiffness). We also determined whether within-food variability in timing parameters is modified in response to changes in food properties. X-ray Reconstruction Of Moving Morphology (XROMM) demonstrates that the timing of jaw movements are flexible in response to changes in food properties. Within each food, pigs also exhibited flexibility in their ability to vary cycle parameters. The timing of jaw movements during processing of high-toughness foods is more variable, potentially decreasing chewing rhythmicity. In contrast, low-toughness foods result in jaw movements that are more stereotyped in their timing parameters. In addition, the duration of tooth-food-tooth contact is more variable during the processing of low-stiffness foods compared with tough or stiff foods. Increased toughness is suggested to alter the timing of the movements impacting food fracture whereas increased stiffness may require a more cautious control of jaw movements. This study emphasizes that flexibility in biological movements in response to changes in conditions may not only be observed in timing but also in the variability of their timing within each condition.

Modeling tics in rodents: Conceptual challenges and paths forward

BACKGROUND

Recent advances in our understanding of the neurobiology of tics have led to the development of novel rodent models capturing different pathophysiological and phenotypic aspects of Tourette syndrome. The proliferation of these models, however, raises vexing questions on what standards should be adopted to assess their theoretical validity and empirical utility. Assessing the homology of a rodent motoric burst with a tic remains problematic, due to our incomplete knowledge of the underpinnings of tics, their high phenotypic complexity and variability, limitations in our ability test key aspects of tic phenomenology (such as premonitory sensory phenomena) in animals, and between-species differences in neuroanatomy and behavioral repertoire. These limitations underscore that any interpretation of behavioral output in an animal model cannot exclusively rely on the recognition of features that bear superficial resemblance with tics, but must be supported by other etiological and convergent phenomenological criteria.

NEW METHOD

Here, we discuss two complementary approaches for the study and validation of tic-like manifestations in rodents, based respectively on the use of contextual modulators and accompanying features of repetitive motor manifestations and on the reproduction of pathogenic factors.

RESULTS

Neither strategy can by itself provide convincing evidence that a model informatively recapitulates tic pathophysiology. Their combination holds promise to enhance the rigorous evaluation and translational relevance of rodent models of tic disorders.

CONCLUSIONS

This systematic consideration of different approaches to the validation and study of animal models of tic pathophysiology provides a framework for future work in this area.

The combination of escitalopram and aripiprazole: Investigation of psychomotor effects in rats

Pre-clinical and clinical evidence suggests that the antidepressant efficacy of the selective serotonin reuptake inhibitor escitalopram can be enhanced by the dopamine and serotonin partial agonist aripiprazole. Given the range of possible neurochemical interactions between these drugs, the current study investigated whether aripiprazole alters the hedonic and psychomotor effects of escitalopram. Male Sprague Dawley rats ( n=116) received 10 mg/kg/day escitalopram (subcutaneous), 2 mg/kg/day aripiprazole (subcutaneous), or combined aripiprazole + escitalopram, and were tested for consumption of incentive nutritional stimuli (high-fructose corn syrup and chow), stereotypy and locomotor activity. At the conclusion of behavioral testing, mRNAs of two genes involved in reward processes were quantified: hypothalamic pro-opiomelanocortin and hippocampal brain-derived neurotrophic factor. Escitalopram produced a selective, but temporary, decrease in high fructose corn syrup consumption that was not altered by aripiprazole co-administration. Escitalopram had no significant effect on locomotion, but aripiprazole co-administration produced a persistent increase in stereotypy. Both brain-derived neurotrophic factor and pro-opiomelanocortin mRNA levels were lower in the aripiprazole + escitalopram group relative to the escitalopram group. Taken together, these results suggest that aripiprazole may enhance the antidepressant efficacy of escitalopram through improvement of psychomotor functions.

Targeted Interneuron Depletion in the Dorsal Striatum Produces Autism-like Behavioral Abnormalities in Male but Not Female Mice

BACKGROUND

Interneuronal pathology is implicated in many neuropsychiatric disorders, including autism spectrum disorder (ASD) and Tourette syndrome (TS). Interneurons of the striatum, including the parvalbumin-expressing fast-spiking interneurons (FSIs) and the large cholinergic interneurons (CINs), are affected in patients with TS and in preclinical models of both ASD and TS.

METHODS

To test the causal importance of these neuronal abnormalities, we recapitulated them in vivo in developmentally normal mice using a combination transgenic-viral strategy for targeted toxin-mediated ablation.

RESULTS

We found that conjoint ~50% depletion of FSIs and CINs in the dorsal striatum of male mice produces spontaneous stereotypy and marked deficits in social interaction. Strikingly, these behavioral effects are not seen in female mice; because ASD and TS have a marked male predominance, this observation reinforces the potential relevance of the finding to human disease. Neither of these effects is seen when only one or the other interneuronal population is depleted; ablation of both is required. Depletion of FSIs, but not of CINs, also produces anxiety-like behavior, as has been described previously. Behavioral pathology in male mice after conjoint FSI and CIN depletion is accompanied by increases in activity-dependent signaling in the dorsal striatum; these alterations were not observed after disruption of only one interneuron type or in doubly depleted female mice.

CONCLUSIONS

These data indicate that disruption of CIN and FSI interneurons in the dorsal striatum is sufficient to produce network and behavioral changes of potential relevance to ASD, in a sexually dimorphic manner.

Low doses of 17α-ethinyl estradiol alter the maternal brain and induce stereotypies in CD-1 mice exposed during pregnancy and lactation

Maternal care is critical for the survival, development and long-term success of offspring. Despite our current understanding of the role of endogenous estrogen in both maternal behavior and the maternal brain, the potential effects of exogenous estrogens on these endpoints remain poorly understood. Here, pregnant CD-1 mice were exposed to low doses of 17α-ethinyl estradiol (EE2), commonly used as a positive control in studies of other xenoestrogens, from day 9 of pregnancy until weaning. Using traditional maternal behavior assays, we document no significant changes in maternal behavior throughout the lactational period. However, EE2 induced increases in repetitive tail retrieval, which may indicate a stereotypy or obsessive compulsive (OCD)-like behavior. We also observed a significant reduction in tyrosine hydroxylase (TH) immunoreactivity in the ventral tegmental area (VTA), a region important for maternal motivation. These results suggest that pregnant adult females are not immune to the effects of this compound.