Autoimmunity in Down's syndrome via cytokines, CD4 T cells and CD11c+ B cells.

Down's syndrome (DS) presents with a constellation of cardiac, neurocognitive and growth impairments. Individuals with DS are also prone to severe infections and autoimmunity including thyroiditis, type 1 diabetes, coeliac disease and alopecia areata1,2. Here, to investigate the mechanisms underlying autoimmune susceptibility, we mapped the soluble and cellular immune landscape of individuals with DS. We found a persistent elevation of up to 22 cytokines at steady state (at levels often exceeding those in patients with acute infection) and detected basal cellular activation: chronic IL-6 signalling in CD4 T cells and a high proportion of plasmablasts and CD11c+TbethighCD21low B cells (Tbet is also known as TBX21). This subset is known to be autoimmune-prone and displayed even greater autoreactive features in DS including receptors with fewer non-reference nucleotides and higher IGHV4-34 utilization. In vitro, incubation of naive B cells in the plasma of individuals with DS or with IL-6-activated T cells resulted in increased plasmablast differentiation compared with control plasma or unstimulated T cells, respectively. Finally, we detected 365 auto-antibodies in the plasma of individuals with DS, which targeted the gastrointestinal tract, the pancreas, the thyroid, the central nervous system, and the immune system itself. Together, these data point to an autoimmunity-prone state in DS, in which a steady-state cytokinopathy, hyperactivated CD4 T cells and ongoing B cell activation all contribute to a breach in immune tolerance. Our findings also open therapeutic paths, as we demonstrate that T cell activation is resolved not only with broad immunosuppressants such as Jak inhibitors, but also with the more tailored approach of IL-6 inhibition.

Modeling the impact of neuromorphological alterations in Down syndrome on fast neural oscillations.

Cognitive disorders, including Down syndrome (DS), present significant morphological alterations in neuron architectural complexity. However, the relationship between neuromorphological alterations and impaired brain function is not fully understood. To address this gap, we propose a novel computational model that accounts for the observed cell deformations in DS. The model consists of a cross-sectional layer of the mouse motor cortex, composed of 3000 neurons. The network connectivity is obtained by accounting explicitly for two single-neuron morphological parameters: the mean dendritic tree radius and the spine density in excitatory pyramidal cells. We obtained these values by fitting reconstructed neuron data corresponding to three mouse models: wild-type (WT), transgenic (TgDyrk1A), and trisomic (Ts65Dn). Our findings reveal a dynamic interplay between pyramidal and fast-spiking interneurons leading to the emergence of gamma activity (∼40 Hz). In the DS models this gamma activity is diminished, corroborating experimental observations and validating our computational methodology. We further explore the impact of disrupted excitation-inhibition balance by mimicking the reduction recurrent inhibition present in DS. In this case, gamma power exhibits variable responses as a function of the external input to the network. Finally, we perform a numerical exploration of the morphological parameter space, unveiling the direct influence of each structural parameter on gamma frequency and power. Our research demonstrates a clear link between changes in morphology and the disruption of gamma oscillations in DS. This work underscores the potential of computational modeling to elucidate the relationship between neuron architecture and brain function, and ultimately improve our understanding of cognitive disorders.

Alterations in aperiodic and periodic EEG activity in young children with Down syndrome.

Down syndrome (DS) is the most common cause of intellectual disability, yet little is known about the neurobiological pathways leading to cognitive impairments. Electroencephalographic (EEG) measures are commonly used to study neurodevelopmental disorders, but few studies have focused on young children with DS. Here we assess resting state EEG data collected from toddlers/preschoolers with DS (n = 29, age 13-48 months old) and compare their aperiodic and periodic EEG features with both age-matched (n = 29) and developmental-matched (n = 58) comparison groups. DS participants exhibited significantly reduced aperiodic slope, increased periodic theta power, and decreased alpha peak amplitude. A majority of DS participants displayed a prominent peak in the theta range, whereas a theta peak was not present in age-matched participants. Overall, similar findings were also observed when comparing DS and developmental-matched groups, suggesting that EEG differences are not explained by delayed cognitive ability.

A landmark-free morphometrics pipeline for high-resolution phenotyping: application to a mouse model of Down syndrome.

Characterising phenotypes often requires quantification of anatomical shape. Quantitative shape comparison (morphometrics) traditionally uses manually located landmarks and is limited by landmark number and operator accuracy. Here, we apply a landmark-free method to characterise the craniofacial skeletal phenotype of the Dp1Tyb mouse model of Down syndrome and a population of the Diversity Outbred (DO) mouse model, comparing it with a landmark-based approach. We identified cranial dysmorphologies in Dp1Tyb mice, especially smaller size and brachycephaly (front-back shortening), homologous to the human phenotype. Shape variation in the DO mice was partly attributable to allometry (size-dependent shape variation) and sexual dimorphism. The landmark-free method performed as well as, or better than, the landmark-based method but was less labour-intensive, required less user training and, uniquely, enabled fine mapping of local differences as planar expansion or shrinkage. Its higher resolution pinpointed reductions in interior mid-snout structures and occipital bones in both the models that were not otherwise apparent. We propose that this landmark-free pipeline could make morphometrics widely accessible beyond its traditional niches in zoology and palaeontology, especially in characterising developmental mutant phenotypes.

Growth charts for weight and height of Indian children with Down syndrome.

Age and gender specific growth charts for Indian children with Down syndrome (DS) based on longitudinal data have not been published. To establish percentile growth charts for DS children inhabiting northwestern parts of India, body weight and length/height of 1125 (Male: 752, Female: 373) children with DS aged <1 month to 10 years, enrolled from the "Genetics Clinic" were measured at half yearly age intervals in the "Growth Clinic" of the Institute from August 1994 to November 2018. A total of 2089 observations were made on these children using standardized anthropometric techniques and instruments following a prospective mixed-longitudinal growth research design. Using the LMS method, age and sex-specific percentile growth charts (<1 month to 10 years) for weight, and length/ height were generated. Unpaired t-test was used to compare mean growth attainments of study children with those of DS patients representing other population groups as well as their normal Multicentre Growth Reference Study (MGRS and Indian Academy of Pediatrics (IAP) counterparts. The 50th percentile growth curves for both weight and length/height of Indian children with DS demonstrated a regular increase. As compared to their normal MGRS and Indian (IAP) counterparts, the children with DS had lower weight and height attainments. The boys and girls with Down syndrome showed short stature (height < 3rd centile) from the age of 1 year till 10 years and also became underweight beyond 5 years. As compared to their normal counterparts, children with Down syndrome exhibited compromised auxological attainments. The use of growth charts presented herein may be used to compare and monitor growth and nutritional status of Indian children with Down syndrome.

Pediatric cervical spine instability: evolving concepts.

The pediatric cervical spine is structurally and biomechanically unique in comparison to adults. Guidelines to assess for cervical spine instability and standard of care treatments in the pediatric population have yet to be delineated. This is due to the rarity of the condition and the lack of multicenter data published on the topic. Our review explores the biomechanics of the pediatric cervical spine and highlights evolving concepts/research over the last several decades, with special attention to the Down syndrome and complex Chiari malformation cohorts.

Why do individuals with Williams syndrome or Down syndrome fail the Weather Prediction Task?

Williams syndrome (WS) and Down syndrome (DS) are two neurodevelopmental disorders with distinct genetic origins characterized by mild to moderate intellectual disability. Individuals with WS or DS exhibit impaired hippocampus-dependent place learning and enhanced striatum-dependent spatial response learning. Here, we used the Weather Prediction Task (WPT), which can be solved using hippocampus- or striatum-dependent learning strategies, to determine whether individuals with WS or DS exhibit similar profiles outside the spatial domain. Only 10% of individuals with WS or DS solved the WPT. We further assessed whether a concurrent memory task could promote reliance on procedural learning to solve the WPT in individuals with WS but found that the concurrent task did not improve performance. To understand how the probabilistic cue-outcome associations influences WPT performance, and whether individuals with WS or DS can ignore distractors, we assessed performance using a visual learning task with differing reward contingencies, and a modified WPT with unpredictive cues. Both probabilistic feedback and distractors negatively impacted the performance of individuals with WS or DS. These findings are consistent with deficits in hippocampus-dependent learning and executive functions, and reveal the importance of congruent feedback and the minimization of distractors to optimize learning in these two populations.

Characterising repetitive behaviours in children and adolescents with Down syndrome.

BACKGROUND: Individuals with intellectual disability, including people with Down syndrome (DS), often exhibit restricted and repetitive behaviours (RRBs). However, RRBs have not been deeply characterised in children and adolescents with DS. METHOD: The study encompassed a cohort of 151 participants aged 4 to 18 years with DS. RRBs were assessed utilising the Repetitive Behaviour Scale-Revised. Additionally, data pertaining to cognitive and adaptive functioning, linguistic abilities, sleep patterns and emotional/behavioural issues were gathered. RESULTS: Self-injurious behaviours were reported less frequently whereas parents most commonly endorsed items related to behaviours associated with the need for sameness and ritualistic behaviours. We observed very few gender differences, whereas some age-related differences emerged, with adolescents exhibiting higher scores in items related with higher-level RRBs. The analysis of the association between RRBs and clinical features revealed that RRBs were associated with parent-reported sleep difficulties, as well as with internalising and externalising problems. We also observed a negative correlation with IQ whereas associations with adaptive skills emerged mainly for lower-level RRBs, such as motor stereotypies. Finally, RRBs were negatively associated with linguistic abilities, both expressive and receptive. CONCLUSIONS: RRBs in children and adolescents with DS are of significant clinical interest due to their associations with various clinical dimensions. Therefore, psychological and neuropsychiatric assessment should include an accurate evaluation of RRBs for young people with DS.

Laboratory-based measures of executive function and daily living skills in young children with Down syndrome: informing future interventions.

BACKGROUND: Adaptive behaviour refers to the practical skills necessary for independence and is considered a high-priority intervention target for children with neurogenetic conditions associated with intellectual disability, like Down syndrome (DS). Daily living skills (DLS) are a critical aspect of adaptive behaviour, but they have received little intervention attention, possibly because they involve a wide variety of skills across many settings. The present study aimed to advance DLS intervention science by examining the concurrent and longitudinal association between DLS performances and a cognitive skillset hypothesised to support DLS skill acquisition, executive function (EF). METHODS: Participants were 71 children with DS between the ages of 2.5 and 8.7 years (M = 5.23 years; standard deviation = 1.65) who completed a battery of adapted EF tasks and a primary caregiver who completed the Vineland Adaptive Behavior Scales 3rd Edition Parent/Caregiver Comprehensive Report Form. A subset of caregivers also provided 6- and 12-month follow-up adaptive behaviour information. RESULTS: Results demonstrated a positive association between EF task performance and DLS standard scores and v-scores both concurrently and longitudinally. CONCLUSIONS: The findings have implications for potential future intervention approaches that aim to strengthen DLS performances by advancing EF skills in this population.

Organised and non-organised activities contribute to overall physical activity levels in adolescents and young adults with Down syndrome: a cross-sectional study.

BACKGROUND: Participation in organised and non-organised physical activities among adolescents and young adults with Down syndrome is underexplored. This study aimed to examine differences between organised and non-organised physical activities among adolescents and young adults with Down syndrome. METHODS: Forty participants with Down syndrome (27 woman; mean age 21.4 ± 4.9 years) were recruited. Data on physical activity participation were collected by self- or proxy-reported questionnaires about attendance, involvement and type of physical activity. RESULTS: Adolescents and young adults with Down syndrome participated in more organised than non-organised activities (P < 0.05), more often (P < 0.05), but there was no difference in the total time spent participating in these activities overall. Participants spent more time in vigorous physical activity during organised activities (P < 0.05) and spent more time in light physical activity during non-organised physical activities (P < 0.05). Dancing (organised activity) and walking (non-organised activity) were the most reported activities. CONCLUSIONS: Participation in both organised and non-organised physical activities is important to increase overall physical activity levels of adolescents and young adults with Down syndrome. Future research exploring physical activity preferences may help guide the planning and adaption of community programmes for this group.

Focused attention and intrinsic motivation using animations for instruction of fundamental motor skills in children with Down syndrome.

BACKGROUND: Children with Down syndrome (DS) demonstrate poorer performance in locomotor and ball skills than children with typical development. During motor assessment, keeping children's attention and motivation is challenging, especially for children with DS, which may affect the test outcomes. This study aimed first to examine the impact of examiner and App-animation demonstrations during the assessment on the performance of fundamental motor skills, focus of attention and intrinsic motivation for children with DS and neurotypical development (NTD). The secondary aim was to examine the differences in those outcomes between children with DS and neurotypical development. METHODS: A sample of 24 children (10 with DS and 14 with NTD) aged between 3 and 10 years were subjected to two motor performance assessment protocols: a traditional protocol using the Gross Motor Development Test-3 (TGMD-3) and a protocol using animations from an application as support for TGMD-3 (AppP). The focus of attention was obtained from video recordings during protocol instruction (number of eye shifts, eye shift time, instruction focus time, number of instructions required and total instruction time). Intrinsic motivation was assessed by the Intrinsic Motivation Inventory (IMI) at the end of each protocol. RESULTS: The results showed no significant differences between the protocols for locomotor skills, ball skills and gross motor index. However, children with NTD outperformed those with DS in these skills. When analysing the focus of attention, children with DS showed greater ocular deviations and longer instruction time requested in the traditional protocol compared with AppP, even when compared with NDT children. When comparing protocols in both groups, AppP demonstrated fewer ocular deviations and shorter ocular deviation times. Regarding intrinsic motivation, children with DS in the traditional protocol had lower motivation scores than those with NTD. Regarding the purchase of protocols, in both groups, the AppP presented higher scores for interest/pleasure, perceived competence and general motivation, with lower pressure/tension. CONCLUSION: The animated application (AppP) proved effective as a visual support during the TGMD-3 assessment, particularly benefiting children with DS by enhancing motivation and attention.

Measurement protocols and determinants of peak oxygen consumption in adults with Down syndrome: a systematic review.

This systematic review aimed to provide an overview of test protocols used to measure peak oxygen uptake (VO2peak) in adults with Down syndrome (DS) and to determine how generalisable the outcomes are for the entire population of adults with DS by describing the sample characteristics of these studies and their impact on VO2peak. A literature search (PROSPERO CRD42022309560) was performed (18 July 2023) using the following databases: PubMed, CINAHL, APA PsycINFO, Web of Science, Embase and SPORTDiscus. For articles to be included, they had to be peer-reviewed pubications, reporting VO2peak or VO2max for individuals with DS separately, with a sample of n ≥ 5 and a mean age ≥18 years. Systematic reviews and meta-analyses were excluded but their reference lists were searched for additional papers to include. Studies were evaluated for risk of bias following the guidelines of Kmet et al. The results were summarised with frequency statistics. Forty-three studies were included in this systematic review. Sample sizes of included adults with DS ranged from n = 4-226, with a total of n = 1498 adults with DS being included. Most studies (29/43) used the same standardised maximal exercise treadmill protocol to measure VO2peak in adults with DS, and 33 out of 43 studies used at least one objective criterion to determine a valid maximal effort. Participants were predominantly male, under 40 years old, and overweight or obese. Additionally, the diversity of study samples was lacking or not reported. The most widely used, standardised, maximal exercise test treadmill protocol is recommended for future use in research and practice, including objective criteria to determine valid maximal effort. The current study samples are not representative of the population of adults with DS in terms of sex, age and diverse backgrounds and therefore likely overestimate VO2peak of this population.

Celiac disease in children and adolescents with Down syndrome: behavioural, adaptive and sleep profiles.

BACKGROUND: Individuals with Down syndrome (DS) exhibit higher risk for celiac disease (CD) than general population. Although literature suggests CD could be associated with behavioural problems in both paediatric and adult age, such association has been poorly explored in children and adolescents DS. Therefore, the current study aimed to investigate differences in emotional/behavioural difficulties, adaptive skills and sleep problems between children with DS with and without CD. METHODS: Data were retrospectively collected from a database including data from 381 individuals with DS (3-18 years). The final sample included 65 participants, 27 with co-occurring CD and 38 age, IQ, sex and body mass index-matched controls without CD. Emotional/behavioural difficulties, adaptive skills and sleep problems were assessed through parent report questionnaires. RESULTS: No group differences emerged in emotional/behavioural difficulties, whereas participants in the CD group showed better adaptive skills in the practical domain than control group. Weak differences emerged in sleep problems. CONCLUSIONS: Youth with DS and co-occurring CD do not exhibit more emotional and behavioural problems than youth with DS without co-occurring CD but exhibit better adaptive skills in the practical domain.

Effects of a 12-week telehealth exercise intervention on gait speed and gait deviations in adults with Down syndrome.

BACKGROUND: Altered gait patterns and reduced walking speed are commonly reported in adults with Down syndrome (DS). Research on the effects of DS-specific exercise programmes on adults with DS is lacking. The purpose of this quasi-experimental study was to evaluate the changes in gait deviations and walking speed in adults with DS after a DS-specific exercise programme. METHODS: Twenty participants underwent a 12-week, DS-specific exercise programme in a telehealth format. Before and after the intervention, gait deviations were assessed with the Ranchos Los Amigos Observational Gait Analysis form, and comfortable walking speed was evaluated with the 4-m walk test. RESULTS: We observed increased comfortable walking speed and reduced gait deviations in the whole gait cycle in adults with DS after the intervention. There were fewer gait deviations during single-leg stance and swing-limb advancement and at the hip, knee and ankle joints after the 12-week exercise programme. CONCLUSIONS: Gait speed and observable gait impairments in adults with DS significantly improved following a 12-week telehealth exercise programme.

A multi-center cross-sectional comparison of parent-reported quality of life and bowel function between anorectal malformation and Hirschsprung's disease patients with versus those without Down syndrome.

PURPOSE: Down syndrome (DS) is a common abnormality associated with anorectal malformation (ARM) and Hirschsprung's disease (HD). However, quality of life (QOL) in ARM and HD patients with DS is under-researched. This study compares parent-reported QOL and bowel function in ARM and HD patients with DS to those without. METHODS: Between December 2020 to February 2023, parents of ARM and HD patients with and without DS aged 3-17 years who had undergone surgery > 12 months prior at four tertiary referral centers were recruited. We used the Pediatric Quality of Life Inventory™ (PedsQL™) Generic Core Scales, General Well-Being (GWB) Scale and Family Impact (FI) Module questionnaires, and the Rintala bowel function score (BFS). RESULTS: There were 101 ARM, 9 (8.9%) of whom had DS; and 87 HD, of whom 6 (6.9%) had DS. Parent-reported Core scores in ARM and HD with DS were comparable to those without DS. However, ARM and HD with DS had worse scores in the FI Module and bowel function than those without DS. CONCLUSION: Although parent-reported QOL in ARM and HD with DS is similar to those without DS, family impact and BFS are worse. Our findings are limited by small sample size in proportion of DS patients.

Fetal hemodynamics and placental histopathology in Down syndrome.

OBJECTIVE: To evaluate the association between Doppler patterns in fetuses with Down syndrome (DS) and their placental histopathologic findings. METHODS: A retrospective cross-sectional study was performed by collecting data from medical records of singleton pregnancies between January 2014 and January 2022, whose fetuses had a confirmed diagnosis of DS either prenatally or postnatally. Placental histopathology, maternal characteristics, and prenatal ultrasound (biometric parameters and umbilical artery [UA] Doppler) were evaluated. RESULTS: Of 69 eligible pregnant women, 61 met the inclusion and exclusion criteria. In the sample, 15 fetuses had an estimated fetal weight < 10th percentile for gestational age (GA) and were considered small for gestational age (SGA). Thirty-eight fetuses had increased resistance on the UA Doppler. Histologic changes were detected in 100% of the placentas, the most common being delayed villous maturation, alterations associated with poor fetal vascular perfusion, and villous dysmorphism. More than 50% of the placentas showed alterations related to placental insufficiency. We did not observe a statistically significant association between UA Doppler examination and placental alterations. All placentas analyzed in the SGA subgroup showed findings compatible with placental insufficiency. CONCLUSION: We found no statistically significant association between placental histopathologic findings and UA Doppler abnormalities in fetuses with DS. The placental alterations identified were delayed villous maturation, alterations associated with poor fetal vascular perfusion, and villous dysmorphism.

Swim, Strength, or Combined Programs: Effect on Health-Related Physical Fitness in Adolescents With Down Syndrome.

The adolescent population with Down syndrome (DS) appears to show higher levels of body fat and lower levels of cardiorespiratory fitness or muscle strength than their peers without disabilities. There is a need to create physical activity programs to improve these data. The aim of this research was to determine the effects of a 16-week swimming program, strength program, and combined program (swimming and strength training) on body composition and health-related physical fitness on adolescents with DS and to assess whether there are differences in the results of the different training programs. Forty-five adolescents (17 female and 28 male; average age 15.5 [1.53] years) with DS were recruited and randomized to three groups (swim [n = 15], strength [n = 15], and combined [n = 15]). Results showed that the swim group had significant improvements in all health-related physical fitness variables and there was an improvement in some body-composition variables (p < .05). The strength and combined groups obtained minor improvements in the variables analyzed. In summary, a 16-week swim program consisting of three sessions of 60 min is able to improve levels of body composition and health-related physical fitness in adolescents with DS. The swim training program seems to be more effective in improving body composition and health-related physical fitness than the strength or combined program. These findings could be useful in different special-education centers due to the predisposition shown by the population with DS to this sport modality.

Visual fixation patterns to AAC displays are significantly correlated with motor selection for individuals with Down syndrome or individuals on the autism spectrum.

Eye tracking research technologies are often used to study how individuals attend visually to different types of AAC displays (e.g. visual scene displays, grid displays). The assumption is that efficiency of visual search may relate to efficiency of motor selection necessary for communication via aided AAC; however, this assumption has not received direct empirical study. We examined the relation between speed of visual search and speed of motor selection of symbols. Ten individuals on the autism spectrum (AS; Study 1) and nine with Down syndrome (DS; Study 2) participated in a search task using simulated AAC displays with a main visual scene display (VSD) and a navigation bar of thumbnail VSDs. Participants were given an auditory prompt to find one of four thumbnail VSDs in the navigation bar. Eye tracking technologies measured how long it took participants to fixate visually on the thumbnail VSD, and recorded how long it took participants to select the thumbnail VSD with a finger. A statistically significant relationship emerged between visual fixation and selection latencies, confirming the positive relationship between visual processing and motor selection for both groups of participants. Eye tracking data may serve as a useful proxy measure for evaluating how display design influences selection of AAC symbols, especially when individuals are unwilling or unable to comply with traditional behaviorally-based assessment tasks.

Prefrontal-hippocampal functional connectivity encodes recognition memory and is impaired in intellectual disability.

Down syndrome (DS) is the most common form of intellectual disability. The cognitive alterations in DS are thought to depend on brain regions critical for learning and memory such as the prefrontal cortex (PFC) and the hippocampus (HPC). Neuroimaging studies suggest that increased brain connectivity correlates with lower intelligence quotients (IQ) in individuals with DS; however, its contribution to cognitive impairment is unresolved. We recorded neural activity in the PFC and HPC of the trisomic Ts65Dn mouse model of DS during quiet wakefulness, natural sleep, and the performance of a memory test. During rest, trisomic mice showed increased theta oscillations and cross-frequency coupling in the PFC and HPC while prefrontal-hippocampal synchronization was strengthened, suggesting hypersynchronous local and cross-regional processing. During sleep, slow waves were reduced, and gamma oscillations amplified in Ts65Dn mice, likely reflecting prolonged light sleep. Moreover, hippocampal sharp-wave ripples were disrupted, which may have further contributed to deficient memory consolidation. Memory performance in euploid mice correlated strongly with functional connectivity measures that indicated a hippocampal control over memory acquisition and retrieval at theta and gamma frequencies, respectively. By contrast, trisomic mice exhibited poor memory abilities and disordered prefrontal-hippocampal functional connectivity. Memory performance and key neurophysiological alterations were rescued after 1 month of chronic administration of a green tea extract containing epigallocatequin-3-gallate (EGCG), which improves executive function in young adults with DS and Ts65Dn mice. Our findings suggest that abnormal prefrontal-hippocampal circuit dynamics are candidate neural mechanisms for memory impairment in DS.

Obstructive sleep apneas naturally occur in mice during REM sleep and are highly prevalent in a mouse model of Down syndrome.

STUDY OBJECTIVES: The use of mouse models in sleep apnea study is limited by the belief that central (CSA) but not obstructive sleep apneas (OSA) occur in rodents. We aimed to develop a protocol to investigate the presence of OSAs in wild-type mice and, then, to apply it to a validated model of Down syndrome (Ts65Dn), a human pathology characterized by a high incidence of OSAs. METHODS: In a pilot study, nine C57BL/6J wild-type mice were implanted with electrodes for electroencephalography (EEG), neck electromyography (nEMG), and diaphragmatic activity (DIA), and then placed in a whole-body-plethysmographic (WBP) chamber for 8 h during the rest (light) phase to simultaneously record sleep and breathing activity. CSA and OSA were discriminated on the basis of WBP and DIA signals recorded simultaneously. The same protocol was then applied to 12 Ts65Dn mice and 14 euploid controls. RESULTS: OSAs represented about half of the apneic events recorded during rapid-eye-movement-sleep (REMS) in each experimental group, while the majority of CSAs were found during non-rapid eye movement sleep. Compared with euploid controls, Ts65Dn mice had a similar total occurrence rate of apneic events during sleep, but a significantly higher occurrence rate of OSAs during REMS, and a significantly lower occurrence rate of CSAs during NREMS. CONCLUSIONS: Mice physiologically exhibit both CSAs and OSAs. The latter appear almost exclusively during REMS, and are highly prevalent in Ts65Dn. Mice may, thus, represent a useful model to accelerate the understanding of the pathophysiology and genetics of sleep-disordered breathing and to help the development of new therapies.