In vivo translocator protein in females with autism spectrum disorder: a pilot study.

Sex-based differences in the prevalence of autism spectrum disorder (ASD) are well-documented, with a male-to-female ratio of approximately 4:1. The clinical presentation of the core symptoms of ASD can also vary between sexes. Previously, positron emission tomography (PET) studies have identified alterations in the in vivo levels of translocator protein (TSPO)-a mitochondrial protein-in primarily or only male adults with ASD, with our group reporting lower TSPO relative to whole brain mean in males with ASD. However, whether in vivo TSPO levels are altered in females with ASD, specifically, is unknown. This is the first pilot study to measure in vivo TSPO in the brain in adult females with ASD using [11C]PBR28 PET-magnetic resonance imaging (MRI). Twelve adult females with ASD and 10 age- and TSPO genotype-matched controls (CON) completed one or two [11C]PBR28 PET-MRI scans. Females with ASD exhibited elevated [11C]PBR28 standardized uptake value ratio (SUVR) in the midcingulate cortex and splenium of the corpus callosum compared to CON. No brain area showed lower [11C]PBR28 SUVR in females with ASD compared to CON. Test-retest over several months showed stable [11C]PBR28 SUVR across time in both groups. Elevated regional [11C]PBR28 SUVR in females with ASD stand in stark contrast to our previous findings of lower regional [11C]PBR28 SUVR in males with ASD. Preliminary evidence of regionally elevated mitochondrial protein TSPO relative to whole brain mean in ASD females may reflect neuroimmuno-metabolic alterations specific to females with ASD.

Guanfacine for the Treatment of Attention-Deficit/Hyperactivity Disorder in Children and Adolescents with Down Syndrome: A Retrospective Chart Review.

Study Design: Retrospective case series. Objectives: The objective of this study was to provide naturalistic data on the use of guanfacine for the treatment of attention-deficit/hyperactivity disorder (ADHD) in a clinically referred sample of youth with Down syndrome (DS). Methods: The medical records of children and adolescents with DS who received guanfacine for the treatment of ADHD from a multidisciplinary neurodevelopmental disorder clinic between September 1, 2011, and September 10, 2021, were reviewed. Demographic and clinical characteristics, guanfacine dose and treatment duration, and adverse effects were recorded. Clinical Global Impression Scale (CGI) scores for ADHD symptom severity (S) and improvement (I) were retrospectively assigned by a child and adolescent psychiatrist based on review of the clinic notes. Response to guanfacine was defined as completion of at least 12 weeks of treatment and a Clinical Global Impression Improvement subscale rating ≤2 (1 = "very much improved" or 2 = "much improved"). Results: Twenty-one patients were eligible for inclusion, of whom 17 (81%) completed at least 12 weeks of guanfacine. Ten of the 21 patients (48%; 95% confidence interval [CI]: 28%-68%) responded to treatment. The median time on guanfacine treatment covered by the clinic notes was 50.4 weeks, with a range of 0.3 weeks to 7.5 years. Thirteen patients (62%) remained on guanfacine at the time of their most recent clinic note. Nine patients had adverse events documented in their clinic notes (43%; 95% CI: 24%-63%), most commonly sleepiness (n = 7) and constipation (n = 2). Conclusion: About half of patients with DS responded to guanfacine for the treatment of ADHD and many tolerated long-term use. Study limitations primarily relate to the retrospective nature of the study and small sample size.

MicroRNA137-loaded lipid nanoparticles regulate synaptic proteins in the prefrontal cortex.

Genome-wide association studies indicate that allele variants in MIR137, the host gene of microRNA137 (miR137), confer an increased risk of schizophrenia (SCZ). Aberrant expression of miR137 and its targets, many of which regulate synaptic functioning, are also associated with an increased risk of SCZ. Thus, miR137 represents an attractive target aimed at correcting the molecular basis for synaptic dysfunction in individuals with high genetic risk for SCZ. Advancements in nanotechnology utilize lipid nanoparticles (LNPs) to transport and deliver therapeutic RNA. However, there remains a gap in using LNPs to regulate gene and protein expression in the brain. To study the delivery of nucleic acids by LNPs to the brain, we found that LNPs released miR137 cargo and inhibited target transcripts of interest in neuroblastoma cells. Biodistribution of LNPs loaded with firefly luciferase mRNA remained localized to the mouse prefrontal cortex (PFC) injection site without circulating to off-target organs. LNPs encapsulating Cre mRNA preferentially co-expressed in neuronal over microglial or astrocytic cells. Using quantitative proteomics, we found miR137 modulated glutamatergic synaptic protein networks that are commonly dysregulated in SCZ. These studies support engineering the next generation of brain-specific LNPs to deliver RNA therapeutics and improve symptoms of central nervous system disorders.

Genetic and epigenetic signatures associated with plasma oxytocin levels in children and adolescents with autism spectrum disorder.

Oxytocin (OT), the brain's most abundant neuropeptide, plays an important role in social salience and motivation. Clinical trials of the efficacy of OT in autism spectrum disorder (ASD) have reported mixed results due in part to ASD's complex etiology. We investigated whether genetic and epigenetic variation contribute to variable endogenous OT levels that modulate sensitivity to OT therapy. To carry out this analysis, we integrated genome-wide profiles of DNA-methylation, transcriptional activity, and genetic variation with plasma OT levels in 290 participants with ASD enrolled in a randomized controlled trial of OT. Our analysis identified genetic variants with novel association with plasma OT, several of which reside in known ASD risk genes. We also show subtle but statistically significant association of plasma OT levels with peripheral transcriptional activity and DNA-methylation profiles across several annotated gene sets. These findings broaden our understanding of the effects of the peripheral oxytocin system and provide novel genetic candidates for future studies to decode the complex etiology of ASD and its interaction with OT signaling and OT-based interventions. LAY SUMMARY: Oxytocin (OT) is an abundant chemical produced by neurons that plays an important role in social interaction and motivation. We investigated whether genetic and epigenetic factors contribute to variable OT levels in the blood. To this, we integrated genetic, gene expression, and non-DNA regulated (epigenetic) signatures with blood OT levels in 290 participants with autism enrolled in an OT clinical trial. We identified genetic association with plasma OT, several of which reside in known autism risk genes. We also show statistically significant association of plasma OT levels with gene expression and epigenetic across several gene pathways. These findings broaden our understanding of the factors that influence OT levels in the blood for future studies to decode the complex presentation of autism and its interaction with OT and OT-based treatment.

Effect of sex and autism spectrum disorder on oxytocin receptor binding and mRNA expression in the dopaminergic pars compacta of the human substantia nigra.

Oxytocin is an endogenous neuropeptide hormone that influences social behaviour and bonding in mammals. Variations in oxytocin receptor (OXTR) expression may play a role in the social deficits seen in autism spectrum disorder. Previous studies from our laboratory found a dense population of OXTR in the human substantia nigra (SN), a basal ganglia structure in the midbrain that is important in both movement and reward pathways. Here, we explore whether differences in OXTR can be identified in the dopaminergic SN pars compacta of individuals with autism. Postmortem human brain tissue specimens were processed for OXTR autoradiography from four groups: males with autism, females with autism, typically developing (TD) males and TD females. We found that females with autism had significantly lower levels of OXTR than the other groups. To examine potential gene expression differences, we performed in situ hybridization in adjacent slides to visualize and quantify OXTR mRNA as well as mRNA for tyrosine hydroxylase. We found no differences in mRNA levels for either gene across the four groups. These results suggest that a dysregulation in local OXTR protein translation or increased OXTR internalization/recycling may contribute to the differences in social symptoms seen in females with autism. This article is part of the theme issue 'Interplays between oxytocin and other neuromodulators in shaping complex social behaviours'.

Prevalence and factors associated with overweight, obesity, and hypertension in a large clinical sample of adults with autism spectrum disorder.

Adults with autism spectrum disorder (ASD) are at risk for excess bodyweight and hypertension, yet the prevalence of and clinical predictors for these health conditions remain unknown. The objective of this study was to assess the prevalence of overweight, obesity, and hypertension in a large clinical sample of adults with a confirmed diagnosis of ASD and to examine potential clinical predictors. This retrospective chart review study included adult subjects (≥ 20 years) with ASD who had been seen within the past 5 years at a multidisciplinary developmental disorders clinic. Data collected from the electronic health record included age, sex, race and ethnicity, cognitive ability, language ability, body mass index (BMI), hypertension, and use of second generation antipsychotic medications (SGAs). Of 622 adults with a confirmed diagnosis of ASD potentially eligible for the study, 483 (78%) had one or more notes in their records from the past 5 years. Those with recent notes were 23% female, 89% White, and had a mean (SD) age of 28.1 (7.1) years. Overall prevalence estimates for adults represented by this predominantly male, White, and young clinical sample were 28% (95% CI 24%, 32%) for overweight (BMI 25-29.9 kg/m2), 35% (95% CI 31%, 40%) for obesity (≥ 30 kg/m2), and 11% (95% CI 9%, 15%) for hypertension. Controlling for age and sex, intellectual disability (ID) was significantly associated with BMI (p = 0.003) but not hypertension (p = 0.69); those with moderate or more severe ID had a mean BMI that was 2.26 kg/m2 (95% CI 0.96, 3.57) lower than those with no ID. Controlling for age and sex, neither language ability, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) subtype of autism, nor past or current use of SGAs were significantly associated with BMI or hypertension. The study identified a high prevalence of overweight and obesity in adults with ASD consistent with the prevalence of these medical comorbidities in the U.S. population.

A randomized double-blind, placebo-controlled pilot trial of mirtazapine for anxiety in children and adolescents with autism spectrum disorder.

This study was a 10-week double-blind, placebo-controlled pilot trial of mirtazapine for anxiety in youth with autism spectrum disorder (ASD). Participants were ages 5 to 17 years with ASD and clinically significant anxiety (Pediatric Anxiety Rating Scale [PARS] score ≥10). Thirty participants were randomized to mirtazapine (7.5-45 mg/day) or placebo in a 2:1 ratio. The co-primary outcome measures were the PARS and the Clinical Global Impressions-Improvement subscale (CGI-I). Mirtazapine resulted in a statistically significant within group decrease in anxiety on the PARS (ES 1.76, p < 0.001). The improvement in PARS score for mirtazapine versus placebo was clinically meaningful but not statistically significant (ES = 0.63, p = 0.64). Forty-seven percent of participants assigned to mirtazapine (95% CI 22%: 74%) and 20% assigned to placebo (95% CI 2%: 60%) were rated "much improved" (CGI-I = 2) or "very much improved" (CGI-I = 1) for anxiety, p = 0.46. No statistically significant differences in mean 10-week changes between mirtazapine and placebo occurred on any outcome measure. There were no statistically significant differences in adverse effect frequency between mirtazapine and placebo. The results are consistent with mirtazapine's safety and tolerability and meet three of four pre-specified indicators of efficacy (statistically significant change in total PARS score for mirtazapine, numerically greater reduction in total PARS score for mirtazapine than placebo, numerically higher number of responders to mirtazapine than placebo, but not greater than 50% of participants receiving mirtazapine rated as responders). Implementation of a larger randomized controlled trial of mirtazapine for the treatment of anxiety in this population is supported.Clinical trial registration information: Mirtazapine Treatment of Anxiety in Children and Adolescents with Pervasive Developmental Disorders; https://clinicaltrials.gov ; NCT01302964.

Buspirone for the Treatment of Generalized Anxiety Disorder in Down Syndrome: 3 Cases.

OBJECTIVE: Reports on the pharmacologic treatment of anxiety, including generalized anxiety disorder (GAD), in individuals with Down syndrome (DS) are lacking. METHODS: We present the case histories of 1 adolescent and 2 young adults with DS and the treatment course of comorbid GAD with buspirone. RESULTS: Treatment with buspirone was safe and well-tolerated and resulted in sustained improvement in symptoms of anxiety for a minimum of 2 years in all 3 cases. CONCLUSION: Buspirone's generally benign adverse effect profile makes it well suited for treating anxiety in individuals with DS in light of their common medical comorbidities.

Intranasal Oxytocin in Children and Adolescents with Autism Spectrum Disorder.

BACKGROUND: Experimental studies and small clinical trials have suggested that treatment with intranasal oxytocin may reduce social impairment in persons with autism spectrum disorder. Oxytocin has been administered in clinical practice to many children with autism spectrum disorder. METHODS: We conducted a 24-week, placebo-controlled phase 2 trial of intranasal oxytocin therapy in children and adolescents 3 to 17 years of age with autism spectrum disorder. Participants were randomly assigned in a 1:1 ratio, with stratification according to age and verbal fluency, to receive oxytocin or placebo, administered intranasally, with a total target dose of 48 international units daily. The primary outcome was the least-squares mean change from baseline on the Aberrant Behavior Checklist modified Social Withdrawal subscale (ABC-mSW), which includes 13 items (scores range from 0 to 39, with higher scores indicating less social interaction). Secondary outcomes included two additional measures of social function and an abbreviated measure of IQ. RESULTS: Of the 355 children and adolescents who underwent screening, 290 were enrolled. A total of 146 participants were assigned to the oxytocin group and 144 to the placebo group; 139 and 138 participants, respectively, completed both the baseline and at least one postbaseline ABC-mSW assessments and were included in the modified intention-to-treat analyses. The least-squares mean change from baseline in the ABC-mSW score (primary outcome) was -3.7 in the oxytocin group and -3.5 in the placebo group (least-squares mean difference, -0.2; 95% confidence interval, -1.5 to 1.0; P = 0.61). Secondary outcomes generally did not differ between the trial groups. The incidence and severity of adverse events were similar in the two groups. CONCLUSIONS: This placebo-controlled trial of intranasal oxytocin therapy in children and adolescents with autism spectrum disorder showed no significant between-group differences in the least-squares mean change from baseline on measures of social or cognitive functioning over a period of 24 weeks. (Funded by the National Institute of Child Health and Human Development; SOARS-B ClinicalTrials.gov number, NCT01944046.).

Selective Serotonin Reuptake Inhibitors for the Treatment of Depression in Adults with Down Syndrome: A Preliminary Retrospective Chart Review Study.

BACKGROUND: Depression is a common psychiatric comorbidity in individuals with Down syndrome (DS), particularly adults, with an estimated lifetime prevalence of at least 10%. The current literature on the treatment of depression in adults with DS is limited to case series published more than two decades ago, prior to the widespread use of modern antidepressant medications such as selective serotonin reuptake inhibitors (SSRIs). The purpose of this retrospective chart review study was to examine the effectiveness, tolerability, and safety of SSRIs for depression in adults with DS. METHODS: Medical records of 11 adults with DS and depression were reviewed. Assignment of scores for severity (S) of symptoms of depression and improvement (I) of symptoms with treatment with an SSRI was made retrospectively using the Clinical Global Impression Scale (CGI). Demographic and clinical characteristics of the study population, SSRI name, dose, and duration of treatment; and adverse effects were also recorded. RESULTS: All 11 patients (7 male, 4 female; mean age = 27.2 years, range 18-46 years) completed a 12-week treatment course with an SSRI. The median duration of time after initiation of the SSRI covered by record review was 2.1 years, with a range of 24 weeks to 6.7 years. Nine of the 11 patients (82%; 95% CI 52%, 95%) were judged responders to SSRIs based on a rating of "much improved" or "very much improved" on the CGI-I after 12 weeks of treatment (median time of follow-up was 14.4 weeks, with a range of 12.0-33.0 weeks). Adverse effects occurred in four patients (36%). The most common adverse effects were daytime sedation and anger. CONCLUSIONS: In this preliminary retrospective study, the majority of patients responded to a 12-week course of SSRI treatment and some tolerated long-term use. Controlled studies are needed to further assess the efficacy, tolerability, and safety of SSRIs for the treatment of depression in adults with DS.

Compositional variation in early-life parenting structures alters oxytocin and vasopressin 1a receptor development in prairie voles (Microtus ochrogaster).

Paternal absence can significantly alter bio-behavioural development in many biparental species. This effect has generally been demonstrated by comparing the development of offspring reared under biparental care with those reared by a single mother. However, studies employing this design conflate two significant modifications to early-life experience: removal of father-specific qualities and the general reduction of offspring-directed care. In the socially monogamous prairie vole (Microtus ochrogaster), the experience of paternal absence without substitution during development inhibits partner preference formation in adulthood, a hallmark of social monogamy, in females and males. Employing alloparents as substitutes for fathers, our previous work demonstrated that paternal absence affects pair-bond formation in female offspring via reduced quantity of care, although it affects pair-bond formation in male offspring by means of a missing paternal quality (or qualities). Here, we present evidence that paternal absence (with and without alloparental substitution) may alter the ontogeny of neural oxytocin receptor (OXTR) and/or vasopressin 1a receptor (AVPR1a) distribution in male and female prairie voles. Compared to biparentally reared controls (BPC), male offspring reared in mother only (MON) and maternal-plus-alloparental (MPA) conditions show lower densities of OXTR in the central amygdala; and MPA males show lower densities of OXTR in the caudate putamen and nucleus accumbens. Early-life experience was not associated with differences in AVPR1a density in males. However, MON and MPA females show greater densities of AVPR1a in the medial amygdala than BPC; and MPA females show greater densities of AVPR1a in the ventromedial nucleus of the hypothalamus. We also demonstrate with corticosterone concentrations that MON and MPA offspring are not differentially susceptible to a stressor (ie, social isolation) than BPC offspring. These findings suggest that paternal absence, although likely not a salient early-life stressor, has neuroendocrine consequences for offspring, some of which may affect partner preference formation.

Neural correlates of mating system diversity: oxytocin and vasopressin receptor distributions in monogamous and non-monogamous Eulemur.

Contemporary theory that emphasizes the roles of oxytocin and vasopressin in mammalian sociality has been shaped by seminal vole research that revealed interspecific variation in neuroendocrine circuitry by mating system. However, substantial challenges exist in interpreting and translating these rodent findings to other mammalian groups, including humans, making research on nonhuman primates crucial. Both monogamous and non-monogamous species exist within Eulemur, a genus of strepsirrhine primate, offering a rare opportunity to broaden a comparative perspective on oxytocin and vasopressin neurocircuitry with increased evolutionary relevance to humans. We performed oxytocin and arginine vasopressin 1a receptor autoradiography on 12 Eulemur brains from seven closely related species to (1) characterize receptor distributions across the genus, and (2) examine differences between monogamous and non-monogamous species in regions part of putative "pair-bonding circuits". We find some binding patterns across Eulemur reminiscent of olfactory-guided rodents, but others congruent with more visually oriented anthropoids, consistent with lemurs occupying an 'intermediary' evolutionary niche between haplorhine primates and other mammalian groups. We find little evidence of a "pair-bonding circuit" in Eulemur akin to those proposed in previous rodent or primate research. Mapping neuropeptide receptors in these nontraditional species questions existing assumptions and informs proposed evolutionary explanations about the biological bases of monogamy.

Developmental Fluoxetine Exposure Alters Behavior and Neuropeptide Receptors in the Prairie Vole.

Developmental exposure to selective serotonin reuptake inhibitor (SSRI) increases the risk of Autism Spectrum Disorder (ASD), however, the underlying neurobiology of this effect is not fully understood. Here we used the socially monogamous prairie vole as a translational model of developmental SSRI exposure. Paired female prairie voles (n = 20) were treated with 5 mg/kg subcutaneous fluoxetine (FLX) or saline (SAL) daily from birth of the second litter until the day of birth of the 4th litter. This design created three cohorts of FLX exposure: postnatal exposure in litter 2, both prenatal and postnatal exposure in litter 3, and prenatal exposure in litter 4. Post-weaning, subjects underwent behavioral testing to detect changes in sociality, repetitive behavior, pair-bond formation, and anxiety-like behavior. Quantitative receptor autoradiography was performed for oxytocin, vasopressin 1a, and serotonin 1a receptor density in a subset of brains. We observed increased anxiety-like behavior and reduced sociality in developmentally FLX exposed adults. FLX exposure decreased oxytocin receptor binding in the nucleus accumbens core and central amygdala, and vasopressin 1a receptor binding in the medial amygdala. FLX exposure did not affect serotonin 1A receptor binding in any areas examined. Changes to oxytocin and vasopressin receptors may underlie the behavioral changes observed and have translational implications for the mechanism of the increased risk of ASD subsequent to prenatal SSRI exposure.

Sex differences in hypothalamic-pituitary-adrenal axis regulation after chronic unpredictable stress.

INTRODUCTION: Exposure to stress, mediated through the hypothalamic-pituitary-adrenal (HPA) axis, elicits sex differences in endocrine, neurological, and behavioral responses. However, the sex-specific factors that confer resilience or vulnerability to stress and stress-associated psychiatric disorders remain largely unknown. The evident sex differences in stress-related disease prevalence suggest the underlying differences in the neurobiological underpinnings of HPA axis regulation. METHOD: Here, we used a chronic unpredictable stress (CUS) model to investigate the behavioral and biochemical responses of the HPA axis in C57BL/6 mice. Animals were tested in the open field and forced swim test to examine anxiety-like and depressive-like behaviors. Plasma corticosterone levels were measured after behavior and CUS, and glucocorticoid receptor (GR) expression and cytosolic and nuclear fractions of binding protein FKBP51 expression were taken to measure function and regulation of the stress response. RESULTS: Our results indicate increased depressive-like behavior in males and females which correlated with increased corticosterone levels following CUS. However, females displayed more anxiety-like behaviors with and without CUS. Interestingly, we found trends toward dysregulation of GR protein expression in CUS females, and an increase in the GR inhibitory protein, FKBP51, in the cytosol of CUS males but not females. CONCLUSION: These results suggest biochemical alterations to the HPA axis regulation which may elicit a glucocorticoid resistance in females after chronic stress and may contribute to the sex-biased vulnerability to stress-related psychiatric disorders.

Separation of Structurally Similar Anabolic Steroids as Cation Adducts in FAIMS-MS.

Novel synthetic anabolic androgenic steroids have been developed not only to dodge current antidoping tests at the professional sports level, but also for consumption by noncompetitive bodybuilders. These novel anabolic steroids are commonly referred to as "designer steroids" and pose a significant risk to users because of the lack of testing for toxicity and safety in animals or humans. Manufacturers of designer steroids dodge regulation by distributing them as nutritional or dietary supplements. Improving the throughput and accuracy of screening tests would help regulators to stay on top of illicit anabolic steroids. High-field asymmetric-waveform ion mobility spectrometry (FAIMS) utilizes an alternating asymmetric electric field to separate ions by their different mobilities at high- and low-fields as they travel through the separation space. When coupled to mass spectrometry (MS), FAIMS enhances the separation of analytes from other interfering compounds with little to no increase in analysis time. Here we investigate the effects of adding various cation species to sample solutions for the separation of structurally similar or isomeric anabolic androgenic steroids. FAIMS-MS spectra for these cation-modified samples show an increased number of compensation field (CF) peaks, some of which are confirmed to be unique for one steroid isomer over another. The CF peaks observed upon addition of cation species correspond to both monomer steroid-cation adduct ions and larger multimer ion complexes. Notably, the number of CF peaks and their CF shifts do not appear to have a straightforward relationship with cation size or electronegativity. Future directions aim at investigating the structures for these analyte-cation adduct ions for building a predictive model for their FAIMS separations.

Beyond the brain: A multi-system inflammatory subtype of autism spectrum disorder.

An immune-mediated subtype of autism spectrum disorder (ASD) has long been hypothesized. This article reviews evidence from family history studies of autoimmunity, immunogenetics, maternal immune activation, neuroinflammation, and systemic inflammation, which suggests immune dysfunction in ASD. Individuals with ASD have higher rates of co-morbid medical illness than the general population. Major medical co-morbidities associated with ASD are discussed by body system. Mechanisms by which FDA-approved and emerging treatments for ASD act upon the immune system are then reviewed. We conclude by proposing the hypothesis of an immune-mediated subtype of ASD which is characterized by systemic, multi-organ inflammation or immune dysregulation with shared mechanisms that drive both the behavioral and physical illnesses associated with ASD. Although gaps in evidence supporting this hypothesis remain, benefits of this conceptualization include framing future research questions that will help define a clinically meaningful subset of patients and focusing clinical interactions on early detection and treatment of high-risk medical illnesses as well as interfering behavioral signs and symptoms across the lifespan.

Non-invasive Eye Tracking Methods for New World and Old World Monkeys.

Eye-tracking methods measure what humans and other animals visually attend to in the environment. In nonhuman primates, eye tracking can be used to test hypotheses about how primates process social information. This information can further our understanding of primate behavior as well as offer unique translational potential to explore causes of or treatments for altered social processing as seen in people with neurodevelopmental disorders such as autism spectrum disorder and schizophrenia. However, previous methods for collecting eye-tracking data in nonhuman primates required some form of head restraint, which limits the opportunities for research with respect to the number of or kinds of primates that can undergo an eye-tracking study. We developed a novel, noninvasive method for collecting eye tracking data that can be used both in animals that are difficult to restrain without sedation as well as animals that are of different ages and sizes as the box size can be adjusted. Using a transport box modified with a viewing window, we collected eye-tracking data in both New (Callicebus cupreus) and Old World monkeys (Macaca mulatta) across multiple developmental time points. These monkeys had the option to move around the box and avert their eyes from the screen, yet, they demonstrated a natural interest in viewing species-specific imagery with no previous habituation to the eye-tracking paradigm. Provided with opportunistic data from voluntary viewing of stimuli, we found that juveniles viewed stimuli more than other age groups, videos were viewed more than static photo imagery, and that monkeys increased their viewing time when presented with multiple eye tracking sessions. This noninvasive approach opens new opportunities to integrate eye-tracking studies into nonhuman primate research.

Buspirone for the treatment of anxiety-related symptoms in Angelman syndrome: a case series.

OBJECTIVES: Angelman syndrome (AS) is a neurogenetic disorder associated with impaired expression of the ubiquitin-protein ligase E3A gene on chromosome 15. AS results in intellectual disability with limited expressive language, epilepsy, ataxia, sleep impairment, and problematic behavior which may include anxiety. Buspirone is a serotonin (5-HT)1A receptor partial agonist used in the treatment of anxiety disorders and may, therefore, have a treatment role for patients with AS. METHODS: We describe three patients who were given open-label buspirone for the treatment of behaviors thought to be related to anxiety. RESULTS: We found significant improvement in symptoms of anxiety with buspirone. Patients tolerated long-term usage of the medication. CONCLUSION: The findings of this study suggest that buspirone may be effective for the amelioration of behaviors related to anxiety in patients with AS, and well tolerated. Limitations include the open-label nature of these treatments, the small sample size and the absence of a control group.

Effect of age and autism spectrum disorder on oxytocin receptor density in the human basal forebrain and midbrain.

The prosocial hormone oxytocin (OXT) has become a new target for research on the etiology and treatment of autism spectrum disorder (ASD), a condition characterized by deficits in social function. However, it remains unknown whether there are alterations in OXT receptor (OXTR) levels in the ASD brain. This study quantified the density of OXTR and of the structurally related vasopressin 1a receptor (AVPR1a) in postmortem brain tissue from individuals with ASD and typically developing individuals. We analyzed two regions known to contain OXTR across all primates studied to date: the nucleus basalis of Meynert (NBM), which mediates visual attention, and the superior colliculus, which controls gaze direction. In the NBM specimens, we also analyzed the neighboring ventral pallidum (VP) and the external segment of the globus pallidus. In the superior colliculus specimens, we also analyzed the adjacent periaqueductal gray. We detected dense OXTR binding in the human NBM and VP and moderate to low OXTR binding in the human globus pallidus, superior colliculus, and periaqueductal gray. AVPR1a binding was negligible across all five regions in all specimens. Compared to controls, ASD specimens exhibited significantly higher OXTR binding in the NBM and significantly lower OXTR binding in the VP, an area in the mesolimbic reward pathway. There was no effect of ASD on OXTR binding in the globus pallidus, superior colliculus, or periaqueductal gray. We also found a significant negative correlation between age and OXTR binding in the VP across all specimens. Further analysis revealed a peak in OXTR binding in the VP in early childhood of typically developing individuals, which was absent in ASD. This pattern suggests a possible early life critical period, which is lacking in ASD, where this important reward area becomes maximally sensitive to OXT binding. These results provide unique neurobiological insight into human social development and the social symptoms of ASD.