Environmental enrichment intervention for Rett syndrome: an individually randomised stepped wedge trial

Molecular insights into enriched environments and behavioral improvements in autism: a systematic review and meta-analysis

Aims

Autism is a multifaceted developmental disorder of the nervous system, that necessitates novel therapeutic approaches beyond traditional medications and psychosomatic therapy, such as appropriate sensory integration training. This systematic mapping review aims to synthesize existing knowledge on enriching environmental interventions as an alternative avenue for improving autism, guiding future research and practice.

Method

A comprehensive search using the terms ASD and Enriched Environment was conducted across PubMed, EMBASE, ISI, Cochrane, and OVID databases. Most of the literature included in this review was derived from animal model experiments, with a particular focus on assessing the effect of EE on autism-like behavior, along with related pathways and molecular mechanisms. Following extensive group discussion and screening, a total of 19 studies were included for analysis.

Results

Enriched environmental interventions exhibited the potential to induce both behavioral and biochemical changes, ameliorating autism-like behaviors in animal models. These improvements were attributed to the targeting of BDNF-related pathways, enhanced neurogenesis, and the regulation of glial inflammation.

Conclusion

This paper underscores the positive impact of enriched environmental interventions on autism through a review of existing literature. The findings contribute to a deeper understanding of the underlying brain mechanisms associated with this intervention.

A Severity Comparison between Italian and Israeli Rett Syndrome Cohorts

Rett syndrome (RTT) is a neurodevelopmental disorder marked by profound cognitive, communication, and motor impairments. Despite identified genotype/phenotype connections, the extent of clinical severity varies even among individuals sharing the same genetic mutation. Diverse sociocultural environments, such as the level of inclusivity of the scholar system, the time spent with family, and the intensity of the rehabilitative intervention provided, might influence their development diversely. This study examines the severity of RTT in people in Italy and Israel, countries with distinct contradictory approaches to caring for those with intricate disabilities, across two age groups. Data from 136 Italian and 59 Israeli girls and women with RTT were assessed and divided into two age categories: above and below 12 years. The RARS, a standardized RTT-specific clinical severity tool, was administered. Despite no differences in age and genetic characteristics, the Italian group showed better scores in the RARS motor and disease-related characteristics areas in both age groups. Moreover, the young Italian participants gathered better total RARS scores and emotional and behavioral characteristics area scores. Furthermore, the young group showed significantly less scoliosis, foot problems, and epilepsy than the older group. These findings endorse the inclusion of girls with RTT in the regular schooling system for a limited daily period, investing in high activity levels within the home and community environments, and suggest continuously providing the person with daily occasions of physical activity and socialization.

Translation, cross-cultural adaptation and validation of the Rett syndrome motor evaluation scale (RESMES): Spanish version

OBJECTIVE

To develop a Spanish version of the Rett Syndrome Motor Evaluation Scale (RESMES) for the locomotor function of Rett Syndrome (RTT) using a transcultural methodology.

METHODS

The RESMES was cross-culturally adaptated and validated in the Spanish language (RESMES-sp). This study was divided into two well-differentiated phases: 1) a cross-cultural translation and adaptation; 2) psychometric characteristics analysis of the RESMES-sp (reliability, test-retest, construct validity, criteria validity, error measurements). For criteria validity, PAINAD questionnaire, the scoliosis values and PedsQL™, were used.

RESULTS

A total of 63 girls and women diagnosed with RTT participated in this validation study. The total value of the RESMES-sp correlates significantly with all its dimensions, with the correlation value oscillating between 0.645 and 0.939. The correlation value with PAINAD ranges between 0.439 and 0.805; the scoliosis values ranges between 0.245 and 0.564; with PedsQOL™ questionnaire, the correlation values range between 0.273 and 0.663 for the PedsQL™ dimensions, and between 0.447 and 0.648 for the total value of PedsQOL™ questionnaire. The reliability values of Crombach's alpha ranged between 0.897 and 0.998 for the intra-observer analyses and between 0.904 and 0.998 for the inter-observer reliability. The SEM showed a value of 2,829, while the MDC90 showed a value of 6601. The Exploratory Factor Analysis showed 6 factors and values of variance of 86.163%.

CONCLUSIONS

The Spanish version of the RESMES is a reliable and valid tool for the functional assessment and follow-up of patients with RTT.

Ayres Sensory Integration Therapy for a Child With Rett Syndrome: A Case Report

Rett syndrome (RTT) is a neurodevelopmental disorder characterized by severe dyspraxia, hand stereotypies, and sensory processing issues for which there is no known treatment. This case describes a child with classic RTT and the child's responses to an Ayres Sensory Integration (ASI) treatment intervention (36 one-hour sessions, 3 per week). We coded and analyzed 36 detailed treatment notes to answer the following questions: What strategies and factors facilitated or interfered with participation in the intervention? What critical elements of treatment documentation might detect small changes in praxis and participation? How do patterns of motor or praxis milestones that emerge over time relate to this child's level of participation? We observed an increase in participation when the therapist incorporated elements of neurodevelopmental treatment (NDT) and motor learning theory- treatment strategies commonly used with children who have neuromotor conditions. This increase in participation in the ASI intervention emerged at approximately the same time that the therapist documented acquisition of new motor and praxis skills. We observed the importance of using: lateral movement activities to develop weight-shifting and bilateral coordination, rotary play to increase trunk rotation and improve postural transitions, and rhythm to promote continuing or initiating actions. The documentation of the specific amounts of assistance and prompting needed during treatment sessions was an important tool for tracking small yet meaningful responses to treatment. This case illustrates a novel use of ASI intervention supplemented with strategies that developed foundational skills, and the emergence of praxis and participation in the therapeutic intervention. We suggest further research is needed to determine efficacy of ASI for other children with this rare disorder.

Regulatory Effects of Maternal Immune Activation and Environmental Enrichment on Glucocorticoid Receptor and FKBP5 Expression in Stress-sensitive Regions of the Offspring Brain

A mother's exposure to immune challenge during pregnancy is well known to be a detrimental factor to the development of the offspring's brain and an impetus for neuropsychiatric disorders. Previous studies have shown that these adverse events can dysregulate the stress response machinery. Two crucial components of the stress axis considered to be affected have been targets in these studies: the glucocorticoid receptor (GR), and FKBP5 which regulates GR activity. The implementation of interventions such as Environmental Enrichment (EE) have shown positive results in protecting the brain against the consequences associated with gestational insults. In light of this, we investigated the transcriptional regulation of GR and FKBP5 from six stress-sensitive brain regions of the offspring using a rat model of maternal immune activation (MIA). Furthermore, we analyzed the effect of an enriched environment on their expression. We found an increase in FKBP5 in MIA rats in five brain regions. RT-qPCR analysis of MIA's effect on GR yielded insignificant results. However, we found that EE increased GR expression in the medial preoptic area which could be indicative of a positive regulation by EE. This study provides evidence of the impact of both gestational insult and EE on the regulation of stress responsive genes in the developing brain.

Development and Psychometric Properties of the Multi-System Profile of Symptoms Scale in Patients with Rett Syndrome

Background: Rett Syndrome (RTT) is a rare, neurodevelopmental disorder characterised by a range of problematic symptoms. There is yet to be a robust instrument to adequately capture the range of disease severity across the lifespan. In this study, we aimed to develop and assess the validity of an RTT-specific electronic Observer Reported Outcome (eObsRO), the Multi-System Profile of Symptoms Scale (MPSS). Methods: The study was conducted in two phases. Phase 1 consisted of a systematic literature review, focus groups, expert feedback, and a pilot test of the new scale. Modifications were made based on preliminary analysis and feedback collected in the pilot phase. Phase 2 consisted of the validation of the questionnaire based on two samples (Sample 1, n = 18; Sample 2, n = 106). Participants were all parents or caregivers of individuals with RTT. Results: The MPSS consists of 12 validated sub-scales (mental health problems, autonomic problems, cardiac problems, communication problems, problems in social behaviour, problems in engagement, gastrointestinal problems, problems in motor skills, neurological problems, orofacial problems, respiratory problems, and sleep problems), which explore symptom frequency in the past month and a supplement to the scale consisting of five sub-scales (sensory problems, immune dysfunction and infection, endocrine problems, skeletal problems, and dermatological problems), which is designed to capture symptom changes over a longer time period. The frequency of symptoms was rated on a 10-point slider scale, which then was automatically transformed into a 0 to 5 Likert score. All 12 sub-scales showed strong internal consistency (α ≥ 0.700) and good stability, ranging from 0.707 to 0.913. Pearson’s correlation showed a statistically significant (r = 0.649) correlation between the MPSS and the Rett Syndrome Behaviour Questionnaire (RSBQ) total score and significant correlations between sub-scales with items that were presented in both the MPSS and RSBQ. Conclusions: The MPSS is a psychometrically validated eObsRO using the HealthTrackerTM platform and has the potential to be used in clinical trials.

[Early prognostic of ASD: A challenge]

Autism Spectrum Disorders (ASD) are born in the womb generated by intrauterine genetic or environmental insult. ASD diagnostic is made at the age of 3-5 years in Europe and in the US. Relying on this, we have tested the hypothesis of identifying already at birth babies who might be diagnosed later with ASD, thereby facilitating an early use of psychoeducative techniques to attenuate the severity of the symptoms. Here, we discuss the various approaches that have been used to enable an early diagnosis. We have ourselves used an approach based on a "without a priori" machine learning analysis of all maternity biological and ultrasound data available in French maternities (around 116) in utero and after birth. This program made it possible to identify at birth almost all (96%) of babies who will be later neurotypical and around half of those who will be diagnosed with ASD. Some of the parameters allowing this identification were largely unexpected with no known links with ASD. This approach will enable an early identification of babies at risk, but also might be used to diagnose ASD later on, and perhaps could help to get a better understanding of the heterogeneity of ASD.

Dysregulated cortical synaptic plasticity under methyl-CpG binding protein 2 deficiency and its implication in motor impairments

Caused by the mutation of methyl-CpG binding protein 2 (MeCP2), Rett syndrome leads to a battery of severe neural dysfunctions including the regression of motor coordination and motor learning. Current understanding has revealed the motor cortex as the critical region mediating voluntary movement. In this review article, we will summarize major findings from human patients and animal models regarding the cortical synaptic plasticity under the regulation of MeCP2. We will also discuss how mutation of MeCP2 leads to the disruption of cortical circuitry homeostasis to cause motor deficits. Lastly, potential values of physical exercise and neuromodulation approaches to recover neural plasticity and motor function will be evaluated. All of this evidence may help to accelerate timely diagnosis and effective interventions for Rett syndrome patients.

The Rett Syndrome Gross Motor Scale - Dutch Version (RSGMS-NL) Can Reliably Assess Gross Motor Skills in Dutch Individuals with Rett Syndrome

AIM

The Rett Syndrome Gross Motor Scale (RSGMS) is an observational measurement, assessing gross motor skills in individuals with Rett syndrome. A Dutch version is lacking. The current study aims to translate and cross-culturally adapt the original RSMGS to Dutch and assess its inter-rater and intra-rater reliability.

DESIGN

Translation and cross-cultural adaptation were performed in concordance with internationally accepted guidelines. A pretest was performed, and expert validation was assured. Video data of three girls with Rett syndrome was independently assessed by 27 physiotherapists via an online webinar to measure inter-rater reliability. Additionally, videos of 17 individuals with Rett syndrome were scored twice by two raters to assess intra-rater reliability. The reliability of the total score, the three subscale scores and the new items were analyzed using Intraclass Correlation Coefficients (ICC).

RESULTS

Good comprehensibility and expert validation of the RSMGS-NL was achieved, and four items were added to the original scale. Inter-rater reliability for the total score was excellent (ICC 0.97, 95% CI 0.89-0.99), and good to perfect inter-rater reliability for the three subscales; Sitting, Standing & walking and Challenge was found (ICC values 1.0 (95% CI 0), 0.98 (95% CI 0.91-0.99) and 0.82 (95% CI 0.93-0.99) respectively). The intra-rater reliability was excellent for the total test score (ICC 0.98, 95% CI 0.97-0.99) and good to excellent for the subscale scores (ICC values 0.87 (95% CI 0.75-0.94), 0.99 (95% CI 0.98-1.0) and 0.97 (95% CI 0.95-0.99) respectively). The four new items (Standing to sitting, walking down a slope, ascending the stairs, descending the stairs) showed good to excellent intra-rater reliability.

CONCLUSION

The RSGMS-NL is a reliable measure of gross motor skills in Dutch individuals with Rett syndrome.

Rett Syndrome and MECP2 Duplication Syndrome: Disorders of MeCP2 Dosage

Rett syndrome (RTT) is a neurodevelopmental disorder caused predominantly by loss-of-function mutations in the gene Methyl-CpG-binding protein 2 (MECP2), which encodes the MeCP2 protein. RTT is a MECP2-related disorder, along with MECP2 duplication syndrome (MDS), caused by gain-of-function duplications of MECP2. Nearly two decades of research have advanced our knowledge of MeCP2 function in health and disease. The following review will discuss MeCP2 protein function and its dysregulation in the MECP2-related disorders RTT and MDS. This will include a discussion of the genetic underpinnings of these disorders, specifically how sporadic X-chromosome mutations arise and manifest in specific populations. We will then review current diagnostic guidelines and clinical manifestations of RTT and MDS. Next, we will delve into MeCP2 biology, describing the dual landscapes of methylated DNA and its reader MeCP2 across the neuronal genome as well as the function of MeCP2 as a transcriptional modulator. Following this, we will outline common MECP2 mutations and genotype-phenotype correlations in both diseases, with particular focus on mutations associated with relatively mild disease in RTT. We will also summarize decades of disease modeling and resulting molecular, synaptic, and behavioral phenotypes associated with RTT and MDS. Finally, we list several therapeutics in the development pipeline for RTT and MDS and available evidence of their safety and efficacy.

A semi-standardized music therapy intervention for girls with Rett syndrome: A descriptive essay

Rett syndrome (RTT) is a severe neurodevelopmental disorder resulting in a wide range of functional impairments and therefore greatly impacts the lives of both patients and their families. While genetic and medical aspects have been studied for several decades, rehabilitation intervention research is still in its infancy. In this study, the investigating researchers have presented a rehabilitative framework by using music therapy for girls with RTT. This model is founded upon the use of music therapy in light of Stern's proposal of subjective experience and affect attunement; it also refers to Rosenbaum's family-centered rehabilitation medicine perspective. This study both describes the theory behind this intervention and presents a newly developed outcome measure. This novel tool may have future clinical and research applications. Music therapy for patients with RTT has not been well researched yet, and, as a result, is not universally recommended. However this study's findings suggest that music therapy is an important component of multidisciplinary therapy. Further collaborative research should be encouraged in order to study and implement the use of music therapy in the treatment of severe disabilities. Projects such as the Enablin+ program with the support from the European Commission constitute fundamental tools in promoting integrative medical research and international networks.

Movement disorders in patients with Rett syndrome: A systematic review of evidence and associated clinical considerations

AIM

This systematic review identified and thematically appraised clinical evidence of movement disorders in patients with Rett syndrome (RTT).

METHOD

Using PRISMA criteria, six electronic databases were searched from inception to April 2021. A thematic analysis was then undertaken on the extracted data to identify potential themes.

RESULTS

Following the thematic analysis, six themes emerged: (i) clinical features of abnormal movement behaviors; (ii) mutational profile and its impact on movement disorders; (iii) symptoms and stressors that impact on movement disorders; (iv) possible underlying neurobiological mechanisms; (v) quality of life and movement disorders; and (vi) treatment of movement disorders. Current guidelines for managing movement disorders in general were then reviewed to provide possible treatment recommendations for RTT.

CONCLUSION

Our study offers an enriched data set for clinical investigations and treatment of fine and gross motor issues in RTT. A detailed understanding of genotype-phenotype relationships of movement disorders allows for more robust genetic counseling for families but can also assist healthcare professionals in terms of monitoring disease progression in RTT. The synthesis also showed that environmental enrichment would be beneficial for improving some aspects of movement disorders. The cerebellum, basal ganglia, alongside dysregulation of the cortico-basal ganglia-thalamo-cortical loop, are likely anatomical targets. A review of treatments for movement disorders also helped to provide recommendations for treating and managing movement disorders in patients with RTT.

Motor training improves coordination and anxiety in symptomatic Mecp2-null mice despite impaired functional connectivity within the motor circuit

Rett syndrome (RTT) is a severe neurodevelopmental disorder caused by loss of function of the X-linked methyl-CpG–binding protein 2 (MECP2). Several case studies report that gross motor function can be improved in children with RTT through treadmill walking, but whether the MeCP2-deficient motor circuit can support actual motor learning remains unclear. We used two-photon calcium imaging to simultaneously observe layer (L) 2/3 and L5a excitatory neuronal activity in the motor cortex (M1) while mice adapted to changing speeds on a computerized running wheel. Despite circuit hypoactivity and weakened functional connectivity across L2/3 and L5a, the Mecp2-null circuit’s firing pattern evolved with improved performance over 2 weeks. Moreover, trained mice became less anxious and lived 20% longer than untrained mice. Because motor deficits and anxiety are core symptoms of RTT, which is not diagnosed until well after symptom onset, these results underscore the benefit of motor learning.

Proteomic and transcriptional changes associated with MeCP2 dysfunction reveal nodes for therapeutic intervention in Rett syndrome

Mutations in the methyl-CpG binding protein 2 (MECP2) gene cause Rett syndrome (RTT), an X-linked neurodevelopmental disorder predominantly impacting females. MECP2 is an epigenetic transcriptional regulator acting mainly to repress gene expression, though it plays multiple gene regulatory roles and has distinct molecular targets across different cell types and specific developmental stages. In this review, we summarize MECP2 loss-of-function associated transcriptome and proteome disruptions, delving deeper into the latter which have been comparatively severely understudied. These disruptions converge on multiple biochemical and cellular pathways, including those involved in synaptic function and neurodevelopment, NF-κB signaling and inflammation, and the vitamin D pathway. RTT is a complex neurological disorder characterized by myriad physiological disruptions, in both the central nervous system and peripheral systems. Thus, treating RTT will likely require a combinatorial approach, targeting multiple nodes within the interactomes of these cellular pathways. To this end, we discuss the use of dietary supplements and factors, namely, vitamin D and polyunsaturated fatty acids (PUFAs), as possible partial therapeutic agents given their demonstrated benefit in RTT and their ability to restore homeostasis to multiple disrupted cellular pathways simultaneously. Further unravelling the complex molecular alterations induced by MECP2 loss-of-function, and contextualizing them at the level of proteome homeostasis, will identify new therapeutic avenues for this complex disorder.

Enhancing Effects of Environmental Enrichment on the Functions of Natural Killer Cells in Mice

The environment of an organism can convey a powerful influence over its biology. Environmental enrichment (EE), as a eustress model, has been used extensively in neuroscience to study neurogenesis and brain plasticity. EE has also been used as an intervention for the treatment and prevention of neurological and psychiatric disorders with limited clinical application. By contrast, the effects of EE on the immune system are relatively less investigated. Recently, accumulating evidence has demonstrated that EE can robustly impact immune function. In this review, we summarize the major components of EE, the impact of EE on natural killer (NK) cells, EE's immunoprotective roles in cancer, and the underlying mechanisms of EE-induced NK cell regulation. Moreover, we discuss opportunities for translational application based on insights from animal research of EE-induced NK cell regulation.

Decline in gross motor skills in adult Rett syndrome; results from a Danish longitudinal study

Longevity of individuals with neurodevelopmental diseases as Rett syndrome (RTT) has increased and many reach adulthood and old age. There is therefore a need to increase knowledge about the course of RTT in adults in order to improve medical care management and quality of life. We did a longitudinal study to address if a possible decline in motor skills in adults with RTT can be explained by the presence of common medical conditions as epilepsy, breathing disturbance, and scoliosis. Data from the Danish RTT database, medical files, and videos from visits at the national Center for Rett syndrome were reviewed. The study included 24 individuals aged 30-66 years at last visit after a follow-up period of 6-12 years. Results showed a clinically observable and significant decline in gross motor skills using the Rett syndrome Gross Motor Scale (RSGMS) with a tendency of less decline in the individuals with the best motor abilities. The frequencies of comorbidities were high. Decline in RSGMS score was associated with the presence of epilepsy and severe scoliosis that had been conservatively managed. The results emphasize that epilepsy plays a significant role in the adult RTT life and management of severe scoliosis in the younger years has impact on the motor abilities in adulthood.

Effects of a remotely supervised motor rehabilitation program for individuals with Rett syndrome at home

PURPOSE

In this study, the effect of a remotely supervised, home-based, family-centered individualized rehabilitation program of motor activities for individuals with Rett syndrome (RTT) was evaluated.

MATERIALS AND METHODS

Thirteen participants with classic genetically confirmed RTT followed by a three-month program of motor activities at home. A total of 47 rehabilitative goals were set. Goals achievement, motor function, and parental satisfaction were evaluated. Each program was carried out by the participant's parents and remotely supervised via Skype calls, twice by a therapist experienced in RTT rehabilitation.

RESULTS

Thirty-seven (78.7%) rehabilitative goals were achieved or overachieved. Ten participants (76.9%) significantly increased their gross motor functional level with a medium size effect (0.604). Parental reports of the involved families suggest, on average, a high level of usefulness of the program (4.4/5), adherence to the program (4.4/5), and general satisfaction (4.5/5).

CONCLUSIONS

Our findings strongly support the implementation of such programs for this population. As these programs were remotely supervised, they can be implemented when the children are away from referenced facilities for long durations, such as during long holidays or a Covid-19 type lockdown.Implications for rehabilitationA remote supervised motor activity program carried out by the primary caregiver supports motor functioning in RTT.Therapists should consider family members' motivation to carry out the activities and integrate them into the family's daily routine.The program should be flexible to adapt to any sudden change in medical and environmental conditions, functional ability, and family members' motivational levels.

Music-Based Intervention Ameliorates Mecp2-Loss-Mediated Sociability Repression in Mice through the Prefrontal Cortex FNDC5/BDNF Pathway

Patients with Rett syndrome (RTT) show severe difficulties with communication, social withdrawl, and learning. Music-based interventions improve social interaction, communication skills, eye contact, and physical skills and reduce seizure frequency in patients with RTT. This study aimed to investigate the mechanism by which music-based interventions compromise sociability impairments in mecp2 ^null/y mice as an experimental RTT model. Male mecp2 ^null/y mice and wild-type mice (24 days old) were randomly divided into control, noise, and music-based intervention groups. Mice were exposed to music or noise for 6 h/day for 3 consecutive weeks. Behavioral patterns, including anxiety, spontaneous exploration, and sociability, were characterized using open-field and three-chamber tests. BDNF, TrkB receptor motif, and FNDC5 expression in the prefrontal cortex (PFC), hippocampus, basal ganglia, and amygdala were probed using RT-PCR or immunoblotting. mecp2 ^null/y mice showed less locomotion in an open field than wild-type mice. The social novelty rather than the sociability of these animals increased following a music-based intervention, suggesting that music influenced the mecp2-deletion-induced social interaction repression rather than motor deficit. Mechanically, the loss of BDNF signaling in the prefrontal cortex and hippocampal regions, but not in the basal ganglia and amygdala, was compromised following the music-based intervention in mecp2 ^null/y mice, whereas TrkB signaling was not significantly changed in either region. FNDC5 expression in the prefrontal cortex region in mecp2 ^null/y mice also increased following the music-based intervention. Collective evidence reveals that music-based interventions improve mecp2-loss-induced social dysfunction. BDNF and FNDC5 signaling in the prefrontal cortex region mediates the music-based-intervention promotion of social interactions. This study gives new insight into the mechanisms underlying the improvement of social behaviors in mice suffering from experimental Rett syndrome following a music-based intervention.

Presymptomatic training mitigates functional deficits in a mouse model of Rett syndrome

Mutations in the X-linked gene MECP2 cause Rett syndrome, a progressive neurological disorder in which children develop normally for the first one or two years of life before experiencing profound motor and cognitive decline^1-3. At present there are no effective treatments for Rett syndrome, but we hypothesized that using the period of normal development to strengthen motor and memory skills might confer some benefit. Here we find, using a mouse model of Rett syndrome, that intensive training beginning in the presymptomatic period dramatically improves the performance of specific motor and memory tasks, and significantly delays the onset of symptoms. These benefits are not observed when the training begins after symptom onset. Markers of neuronal activity and chemogenetic manipulation reveal that task-specific neurons that are repeatedly activated during training develop more dendritic arbors and have better neurophysiological responses than those in untrained animals, thereby enhancing their functionality and delaying symptom onset. These results provide a rationale for genetic screening of newborns for Rett syndrome, as presymptomatic intervention might mitigate symptoms or delay their onset. Similar strategies should be studied for other childhood neurological disorders.

Hypothalamic gene transfer of BDNF promotes healthy aging

The aging process and age-related diseases all involve metabolic decline and impaired ability to cope with adversity. Environmental enrichment (EE)-a housing environment which recapitulates aspects of active lifestyle-exerts a wide range of health benefits in laboratory rodents. Brain-derived neurotrophic factor (BDNF) in the hypothalamus orchestrates autonomic and neuroendocrine processes, serving as one key brain mediator of EE-induced resistance to obesity, cancer, and autoimmunity. Recombinant adeno-associated virus (AAV)-mediated hypothalamic BDNF gene transfer alleviates obesity, diabetes, and metabolic syndromes in both diet-induced and genetic models. One recent study by our lab demonstrates the efficacy and safety of a built-in autoregulatory system to control transgene BDNF expression, mimicking the body's natural feedback systems in middle-age mice. Twelve-month old mice were treated with autoregulatory BDNF vector and monitored for 7months. BDNF gene transfer prevented age-associated metabolic decline by: reducing adiposity, preventing the decline of brown fat activity, increasing adiponectin while reducing leptin and insulin in circulation, improving glucose tolerance, increasing energy expenditure, alleviating hepatic steatosis, and suppressing inflammatory genes in the hypothalamus and adipose tissues. Furthermore, BDNF treatment reduced anxiety-like and depression-like behaviors. This chapter summarizes this work and discusses potential roles that hypothalamic BDNF might play in promoting healthy aging.

Role of phosphodiesterases in the pathophysiology of neurodevelopmental disorders

Phosphodiesterases (PDEs) are enzymes involved in the homeostasis of both cAMP and cGMP. They are members of a family of proteins that includes 11 subfamilies with different substrate specificities. Their main function is to catalyze the hydrolysis of cAMP, cGMP, or both. cAMP and cGMP are two key second messengers that modulate a wide array of intracellular processes and neurobehavioral functions, including memory and cognition. Even if these enzymes are present in all tissues, we focused on those PDEs that are expressed in the brain. We took into consideration genetic variants in patients affected by neurodevelopmental disorders, phenotypes of animal models, and pharmacological effects of PDE inhibitors, a class of drugs in rapid evolution and increasing application to brain disorders. Collectively, these data indicate the potential of PDE modulators to treat neurodevelopmental diseases characterized by learning and memory impairment, alteration of behaviors associated with depression, and deficits in social interaction. Indeed, clinical trials are in progress to treat patients with Alzheimer's disease, schizophrenia, depression, and autism spectrum disorders. Among the most recent results, the application of some PDE inhibitors (PDE2A, PDE3, PDE4/4D, and PDE10A) to treat neurodevelopmental diseases, including autism spectrum disorders and intellectual disability, is a significant advance, since no specific therapies are available for these disorders that have a large prevalence. In addition, to highlight the role of several PDEs in normal and pathological neurodevelopment, we focused here on the deregulation of cAMP and/or cGMP in Down Syndrome, Fragile X Syndrome, Rett Syndrome, and intellectual disability associated with the CC2D1A gene.

Rehabilitation therapies in Rett syndrome across the lifespan: A scoping review of human and animal studies

PURPOSE

To perform a scoping review of the evidence for therapeutic interventions to manage functional impairments associated with Rett syndrome (RTT) throughout the lifespan.

METHODS

MEDLINE, EMBASE, PsycINFO, CENTRAL, CINAHL, Scopus and Index to Chiropractic Literature were searched systematically up to December 2019. Two investigators independently reviewed all search results and extracted those that met the inclusion criteria. Human and animal model studies pertaining to therapies that increase functional ability or treat RTT-associated symptoms in all age groups were included. Relevant studies were grouped into intervention categories and rated using the Oxford Centre of Evidence Based Medicine Levels of Evidence. Demographics of participants, interventions, and outcomes were summarized.

RESULTS

Ninety-one articles representing 88 studies met the inclusion criteria, of which 80 were human clinical studies and eight were studies using animal models. Study designs were primarily case series and only six studies involved participants above the age of 40.

CONCLUSION

A small number of rigorously studied rehabilitation interventions have been published. Published studies aim to address a wide variety of functional impairments. Research regarding implementation of therapies for older patients with RTT is lacking and requires further exploration.

Induction of long-term potentiation at Schaffer collateral-CA1 synapses in mice hippocampus after IMPX977 administration

Objective

To investigate the effects of IMPX977 on long term potentiation (LTP) at Schaffer collateral-CA1 synapses in vitro and on methyl CpG binding protein 2 (Mecp2) expression in mice cortex and hippocampus.

Methods

Thirty-two C57BL/6 mice were randomly divided into four groups: control, olive oil (vehicle), IMPX977 low (5 mg/kg) and high (15 mg/kg) groups. Mice were administrated every other day orally for two weeks. Extracellular recording technique in vitro was used to record the effects of IMPX977 on Schaffer collateral-CA1 LTP pathway in acute mice hippocampal slices. The Mecp2 protein expression level was detected by Western blotting.

Results

Compared to the control group, vehicle did not alter the synaptic transmission in Schaffer collateral-CA1 synapses, however, IMPX977 at concentrations of 5 mg/kg and 15 mg/kg significantly enhanced fEPSP (field excitatory postsynaptic potential) slope in Schaffer collateral-CA1 pathway to (179.6 ± 17.8)% and (191.4 ± 21.4)%, individually 60 min after HFS, IMPX977 improved LTP induction significantly at Schaffer collateral-CA1 pathway at least. Also, IMPX977 significantly elevated MeCP2 protein level in cortex.

Conclusion

The effects of IMPX977 on synaptic transmission and Mecp2 protein expression provided convincing evidence that IMPX977 could be promising new drug candidates for Rett syndrome treatment.

Implementing telehealth support to increase physical activity in girls and women with Rett syndrome-ActivRett: protocol for a waitlist randomised controlled trial

INTRODUCTION

Individuals with Rett syndrome (RTT) experience impaired gross motor skills, limiting their capacity to engage in physical activities and participation in activities. There is limited evidence of the effectiveness of supported physical activity interventions. This study aims to evaluate the effects of a telehealth-delivered physical activity programme on physical activity, sedentary behaviour and quality of life in RTT.

METHODS AND ANALYSIS

This is a multicentre study, conducted in Australia, Denmark and Israel. It is a randomised waitlist-controlled trial comparing an intervention to support physical activity with usual care. Participants are children and adults with RTT, recruited from the Australian Rett Syndrome Database, the Danish Center for Rett Syndrome and the Rett Syndrome Association of Israel. The intervention duration is 12 weeks, including fortnightly telephone contact to plan, monitor and develop individual activity programmes. Outcomes are measured at baseline, at 13 weeks and then at 25 weeks. The primary outcomes are sedentary behaviour assessed with an activPAL accelerometer and the number of daily steps measured with a StepWatch Activity Monitor. Secondary outcomes include sleep, behaviour and quality of life. Caregiver experiences will be assessed immediately after the intervention using a satisfaction questionnaire. Group differences for each outcome will be evaluated with analysis of covariance, adjusting for baseline values on an intention-to-treat basis.

ETHICS AND DISSEMINATION

Ethics approval has been obtained in Western Australia from the Child and Adolescent Health Services (RGS3371), in Denmark from the Capital Region Ethics Committee (H-19040514) and in Israel from the Ariel University Institutional Review Board (AU-HEA-ML-20190331). Manuscripts on the development of the intervention from pilot work and the results of the intervention will be submitted to peer-reviewed journals. Results will be presented at conferences and consumer forums. We will develop an online resource documenting the physical activity programme and available supporting evidence.

TRIAL REGISTRATION NUMBER

NCT04167059; Pre-results.

Gross Motor, Physical Activity and Musculoskeletal Disorder Evaluation Tools for Rett Syndrome: A Systematic Review

In recent years, much attention has been paid to motor impairment of persons with Rett Syndrome (RTT), with increasing literature aimed to describe gross motor functioning and musculoskeletal disorders of the RTT population. The aim of this systematic review is to describe clinical evaluation tools used in the last decade to assess motor functioning and musculoskeletal abnormalities of patients with RTT. Thirty-four studies were reviewed and 20 tools were presented. Results showed that only two tools were used to measure functional change after rehabilitative or therapeutic interventions. This review underlies the lack of adequate evaluation tools to assess musculoskeletal abnormalities and deformities in RTT population. The absence of these assessments could be due to a statistical difficulty as it is challenging to build an evaluation tool that can score the entities of the abnormalities related to the amount of disability they cause.

Voluntary Physical Exercise Reduces Motor Dysfunction and Hampers Tumor Cell Proliferation in a Mouse Model of Glioma

Currently, high-grade gliomas are the most difficult brain cancers to treat and all the approved experimental treatments do not offer long-term benefits regarding symptom improvement. Epidemiological studies indicate that exercise decreases the risk of brain cancer mortality, but a direct relationship between physical exercise and glioma progression has not been established so far. Here, we exploited a mouse model of high-grade glioma to directly test the impact of voluntary physical exercise on the tumor proliferation and motor capabilities of affected animals. We report that exposing symptomatic, glioma-bearing mice to running wheels (i) reduced the proliferation rate of tumors implanted in the motor cortex and (ii) delayed glioma-induced motor dysfunction. Thus, voluntary physical exercise might represent a supportive intervention that complements existing neuro-oncologic therapies, contributing to the preservation of functional motor ability and counteracting the detrimental effects of glioma on behavioral output.

Rehabilitation interventions in Rett syndrome: a scoping review

AIM

To summarize existing interventions and their outcomes in Rett syndrome (RTT) rehabilitation and identify gaps in the literature.

METHOD

Five databases (Ovid MEDLINE, Ovid Embase Classic, Ovid PsycINFO, EBSCO CINAHL Plus, and ProQuest ERIC) were systematically searched up to 23rd July 2018 for studies describing rehabilitation interventions. Data on study participants, design, and outcomes were extracted.

RESULTS

Sixty-two articles were included in the final review. Evidence consistently demonstrated that females with RTT can improve their gross motor, fine motor, and communicative skills with rehabilitation. All 11 interventions targeting gross motor function, namely ambulation, achieved functional improvements. Twenty of 24 articles describing fine motor rehabilitation studies succeeded in decreasing stereotypies, improving functional hand use, and/or reducing self-injurious behaviors. Twenty-one of 22 studies describing communication interventions succeeded in training choice-making, communicative language, or socialization behavior. Other key findings include the positive interplay between physical and communicative rehabilitation outcomes, and the ability of females with RTT to improve their cognitive abilities during intervention.

INTERPRETATION

Rehabilitation can impact the daily lives of females with RTT and their caregivers in clinically meaningful ways.

Evidence-Based Physical Therapy for Individuals with Rett Syndrome: A Systematic Review

Rett syndrome is a rare genetic disorder that affects brain development and causes severe mental and physical disability. This systematic review analyzes the most recent evidence concerning the role of physical therapy in the management of individuals with Rett syndrome. The review was carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A total of 17319 studies were found in the main scientific databases. Applying the inclusion/exclusion criteria, 22 studies were admitted to the final phase of the review. Level of evidence of the included studies was assessed using the Oxford Centre for Evidence-Based Medicine—Levels of Evidence guide. Nine approaches to physical therapy for patients with Rett syndrome were identified: applied behavior analysis, conductive education, environmental enrichment, traditional physiotherapy with or without aids, hydrotherapy, treadmill, music therapy, computerized systems, and sensory-based treatment. It has been reported that patients had clinically benefited from the analysed approaches despite the fact that they did not have strong research evidence. According to the results, a multimodal individualized physical therapy program should be regularly recommended to patients with Rett syndrome in order to preserve autonomy and to improve quality of life. However, more high-quality studies are needed to confirm these findings.

Consensus guidelines on managing Rett syndrome across the lifespan

BACKGROUND

Rett syndrome (RTT) is a severe neurodevelopmental disorder with complex medical comorbidities extending beyond the nervous system requiring the attention of health professionals. There is no peer-reviewed, consensus-based therapeutic guidance to care in RTT. The objective was to provide consensus on guidance of best practice for addressing these concerns.

METHODS

Informed by the literature and using a modified Delphi approach, a consensus process was used to develop guidance for care in RTT by health professionals.

RESULTS

Typical RTT presents early in childhood in a clinically recognisable fashion. Multisystem comorbidities evolve throughout the lifespan requiring coordination of care between primary care and often multiple subspecialty providers. To assist health professionals and families in seeking best practice, a checklist and detailed references for guidance were developed by consensus.

CONCLUSIONS

The overall multisystem issues of RTT require primary care providers and other health professionals to manage complex medical comorbidities within the context of the whole individual and family. Given the median life expectancy well into the sixth decade, guidance is provided to health professionals to achieve current best possible outcomes for these special-needs individuals.

Environmental influences on placental programming and offspring outcomes following maternal immune activation

Adverse experiences during pregnancy induce placental programming, affecting the fetus and its developmental trajectory. However, the influence of 'positive' maternal experiences on the placenta and fetus remain unclear. In animal models of early life stress, environmental enrichment (EE) has ameliorated and even prevented associated impairments in brain and behavior. Here, using a maternal immune activation (MIA) model in rats, we test whether EE attenuates maternal, placental and/or fetal responses to an inflammatory challenge, thereby offering a mechanism by which fetal programming may be prevented. Moreover, we evaluate life-long EE exposure on offspring development and examine a constellation of genes and epigenetic writers that may protect against MIA challenges. In our model, maternal plasma corticosterone and interleukin-1β were elevated 3 h after MIA, validating the maternal inflammatory response. Evidence for developmental programming was demonstrated by a simultaneous decrease in the placental enzymes Hsd11b2 and Hsd11b2/Hsd11b1, suggesting disturbances in glucocorticoid metabolism. Reductions of Hsd11b2 in response to challenge is thought to result in excess glucocorticoid exposure to the fetus and altered glucocorticoid receptor expression, increasing susceptibility to behavioral impairments later in life. The placental, but not maternal, glucocorticoid implications of MIA were attenuated by EE. There were also sustained changes in epigenetic writers in both placenta and fetal brain as a consequence of environmental experience and sex. Following MIA, both male and female juvenile animals were impaired in social discrimination ability. Life-long EE mitigated these impairments, in addition to the sex specific MIA associated disruptions in central Fkbp5 and Oprm1. These data provide the first evidence that EE protects placental functioning during stressor exposure, underscoring the importance of addressing maternal health and well-being throughout pregnancy. Future work must evaluate critical periods of EE use to determine if postnatal EE experience is necessary, or if prenatal exposure alone is sufficient to confer protection.

Kinematics associated with treadmill walking in Rett syndrome

BACKGROUND AND PURPOSE

Individuals with Rett syndrome suffer from severely impaired cognitive and motor performance. Current movement-related therapeutic programs often include traditional physical therapy activities and assisted treadmill walking routines for those individuals who are ambulatory. However, there are no quantitative reports of kinematic gait parameters obtained during treadmill walking. The purpose of this research was to characterize the kinematic patterns of the lower limbs during treadmill walking as speed was slowly increased.

METHODS

Seventeen independently ambulatory females diagnosed with a methyl-CpG-binding protein 2 gene mutation walked on a motorized treadmill while joint kinematics were obtained by a camera-based motion capture system and analysis software.

RESULTS

Stride times progressively decreased as treadmill speeds increased. There were significant main effects of speed on sagittal knee and hip ranges of motion and hip velocity. There were large joint asymmetries and variance values relative to other ambulatory patient populations, although variance values decreased as walking speed increased.

CONCLUSIONS

The results indicate that individuals with Rett syndrome can adapt their kinematic gait patterns in response to increasing treadmill speed, but only within a narrow range of speeds. We suggest that treadmill training for ambulatory individuals with Rett syndrome may promote improved walking kinematics and possibly provide overall health benefits.Implications for rehabilitationWalking is an activity that can counter the negative impacts of the sedentary lifestyle of many individuals with disabilities, including those individuals with Rett syndrome.Documentation of the lower limb kinematic patterns displayed during walking by ambulatory females with Rett syndrome can be used by clinicians to evaluate their patients' gait performance in response to therapeutic and pharmacological interventions designed to promote walking.The ability to adapt to increases in treadmill speed suggests that a training program of treadmill walking may be effective in promoting improved gait performance in individuals with Rett syndrome.

Towards a better diagnosis and treatment of Rett syndrome: a model synaptic disorder

With the recent 50th anniversary of the first publication on Rett syndrome, and the almost 20 years since the first report on the link between Rett syndrome and MECP2 mutations, it is important to reflect on the tremendous advances in our understanding and their implications for the diagnosis and treatment of this neurodevelopmental disorder. Rett syndrome features an interesting challenge for biologists and clinicians, as the disorder lies at the intersection of molecular mechanisms of epigenetic regulation and neurophysiological alterations in synapses and circuits that together contribute to severe pathophysiological endophenotypes. Genetic, clinical, and neurobiological evidences support the notion that Rett syndrome is primarily a synaptic disorder, and a disease model for both intellectual disability and autism spectrum disorder. This review examines major developments in both recent neurobiological and preclinical findings of Rett syndrome, and to what extent they are beginning to impact our understanding and management of the disorder. It also discusses potential applications of knowledge on synaptic plasticity abnormalities in Rett syndrome to its diagnosis and treatment.

From Basic Visual Science to Neurodevelopmental Disorders: The Voyage of Environmental Enrichment-Like Stimulation

Genes and environmental stimuli cooperate in the regulation of brain development and formation of the adult neuronal architecture. Genetic alterations or exposure to perturbing environmental conditions, therefore, can lead to altered neural processes associated with neurodevelopmental disorders and brain disabilities. In this context, environmental enrichment emerged as a promising and noninvasive experimental treatment for favoring recovery of cognitive and sensory functions in different neurodevelopmental disorders. The aim of this review is to depict, mainly through the much explicative examples of amblyopia, Down syndrome, and Rett syndrome, the increasing interest in the potentialities and applications of enriched environment-like protocols in the field of neurodevelopmental disorders and the understanding of the molecular mechanisms underlying the beneficial effects of these protocols, which might lead to development of pharmacological interventions.

Resilience priming: Translational models for understanding resiliency and adaptation to early life adversity

Despite the increasing attention to early life adversity and its long-term consequences on health, behavior, and the etiology of neurodevelopmental disorders, our understanding of the adaptations and interventions that promote resiliency and rescue against such insults are underexplored. Specifically, investigations of the perinatal period often focus on negative events/outcomes. In contrast, positive experiences (i.e. enrichment/parental care//healthy nutrition) favorably influence development of the nervous and endocrine systems. Moreover, some stressors result in adaptations and demonstrations of later-life resiliency. This review explores the underlying mechanisms of neuroplasticity that follow some of these early life experiences and translates them into ideas for interventions in pediatric settings. The emerging role of the gut microbiome in mediating stress susceptibility is also discussed. Since many negative outcomes of early experiences are known, it is time to identify mechanisms and mediators that promote resiliency against them. These range from enrichment, quality parental care, dietary interventions and those that target the gut microbiota.

Key issues in Rett syndrome: emotional, behavioural and autonomic dysregulation (EBAD) - a target for clinical trials

Complex neurodevelopmental disorders need multi-disciplinary treatment approaches for optimal care. The clinical effectiveness of treatments is limited in patients with rare genetic syndromes with multisystem morbidity. Emotional and behavioural dysregulation is common across many neurodevelopmental disorders. It can manifest in children across multiple diagnostic groups, including those on the autism spectrum and in rare genetic syndromes such as Rett Syndrome (RTT). There is, however a remarkable scarcity in the literature on the impact of the autonomic component on emotional and behavioural regulation in these disorders, and on the longer-term outcomes on disorder burden.RTT is a debilitating and often life-threatening disorder involving multiple overlapping physiological systems. Autonomic dysregulation otherwise known as dysautonomia is a cardinal feature of RTT characterised by an imbalance between the sympathetic and parasympathetic arms of the autonomic nervous system. Unlocking the autonomic component of emotional and behavioural dysregulation would be central in reducing the impairment seen in patients with RTT. In this vein, Emotional, Behavioural and Autonomic Dysregulation (EBAD) would be a useful construct to target for treatment which could mitigate burden and improve the quality of life of patients.RTT can be considered as a congenital dysautonomia and because EBAD can give rise to impairments occurring in multiple overlapping physiological systems, understanding these physiological responses arising out of EBAD would be a critical part to consider when planning treatment strategies and improving clinical outcomes in these patients. Biometric guided pharmacological and bio-feedback therapy for the behavioural and emotional aspects of the disorder offers an attracting perspective to manage EBAD in these patients. This can also allow for the stratification of patients into clinical trials and could ultimately help streamline the patient care pathway for optimal outcomes.The objectives of this review are to emphasise the key issues relating to the management of EBAD in patients with RTT, appraise clinical trials done in RTT from the perspective of autonomic physiology and to discuss the potential of EBAD as a target for clinical trials.

Environmental Enrichment and Successful Aging

The human brain sustains a slow but progressive decline in function as it ages and these changes are particularly profound in cognitive processing. A potential contributor to this deterioration is the gradual decline in the functioning of multiple sensory systems and the effects they have on areas of the brain that mediate cognitive function. In older adults, diminished capacity is typically observed in the visual, auditory, masticatory, olfactory, and motor systems, and these age-related declines are associated with both a decline in cognitive proficiency, and a loss of neurons in regions of the brain. We will review how the loss of hearing, vision, mastication skills, olfactory impairment, and motoric decline accompany cognitive loss, and how improved functioning of these systems may aid in the restoration of the cognitive abilities in older adults. The human brain appears to require a great deal of stimulation to maintain its cognitive efficacy as people age and environmental enrichment may aid in its maintenance and recovery.