Continuing trial responsibilities for implantable neural devices.

Participants of neural implant studies have research-related posttrial care needs (e.g., hardware replacements). Gaps in plans for posttrial care are currently common, which can have major consequences for patients. Professionals and organizations involved should address important unmet posttrial needs.

Advancing scientific excellence through inclusivity in the NIH BRAIN Initiative.

Leveraging breadth and depth of the scientific workforce invites creativity, relevance, and differing views that directly tie into innovation and problem solving. The NIH BRAIN Initiative is using a multi-pronged strategy to enhance diversity and inclusion toward promoting the best science.

A call to action to address rural mental health disparities.

Rural residents in the USA experience significant disparities in mental health outcomes even though the prevalence of mental illness in rural and metropolitan areas is similar. This is a persistent problem that requires innovative approaches to resolve. Adopting and appropriately modifying the National Institute on Minority Health and Health Disparities research framework are the potential approaches to understanding how these disparities might be addressed through research. Using this research framework can facilitate interrogation of multiple levels of influence, encompassing complex domains of influence and consideration of the entire life course trajectory, which is consistent with several National Institute of Mental Health priorities.

Alaska Native genomic research: perspectives from Alaska Native leaders, federal staff, and biomedical researchers.

Meaningful engagement of Alaska Native (AN) tribes and tribal health organizations is essential in the conduct of socially responsible and ethical research. As genomics becomes increasingly important to advancements in medicine, there is a risk that populations not meaningfully included in genomic research will not benefit from the outcomes of that research. AN people have historically been underrepresented in biomedical research; AN underrepresentation in genomics research is compounded by mistrust based on past abuses, concerns about privacy and data ownership, and cultural considerations specific to this type of research. Working together, the National Human Genome Research Institute and two Alaska Native health organizations, Southcentral Foundation and the Alaska Native Health Board, cosponsored a workshop in July 2018 to engage key stakeholders in discussion, strengthen relationships, and facilitate partnership and consideration of participation of AN people in community-driven biomedical and genomic research. AN priorities related to translation of genomics research to health and health care, return of genomic results, design of research studies, and data sharing were discussed. This report summarizes the perspectives that emerged from the dialogue and offers considerations for effective and socially responsible genomic research partnerships with AN communities.

Accelerating a paradigm shift: The Common Fund Single Cell Analysis Program.

It has become exceedingly important to understand the precise molecular profiles of the nearly 40 trillion cells in an adult human because of their role in determining health, disease, and therapeutic outcome. The National Institutes of Health (NIH) Common Fund-supported Single Cell Analysis Program (SCAP) was designed to address this challenge. In this review, we outline the original program goals and provide a perspective on the impact of the program as a catalyst for exploration of heterogeneity of human tissues at the cellular level. We believe that the technological advances in single-cell RNA sequencing and multiplexed imaging combined with computational methods made by this program will undoubtedly have an impact on broad and robust applications of single-cell analyses in both health and disease research.

The State of the NIH BRAIN Initiative.

The BRAIN Initiative arose from a grand challenge to "accelerate the development and application of new technologies that will enable researchers to produce dynamic pictures of the brain that show how individual brain cells and complex neural circuits interact at the speed of thought." The BRAIN Initiative is a public-private effort focused on the development and use of powerful tools for acquiring fundamental insights about how information processing occurs in the central nervous system (CNS). As the Initiative enters its fifth year, NIH has supported >500 principal investigators, who have answered the Initiative's challenge via hundreds of publications describing novel tools, methods, and discoveries that address the Initiative's seven scientific priorities. We describe scientific advances produced by individual laboratories, multi-investigator teams, and entire consortia that, over the coming decades, will produce more comprehensive and dynamic maps of the brain, deepen our understanding of how circuit activity can produce a rich tapestry of behaviors, and lay the foundation for understanding how its circuitry is disrupted in brain disorders. Much more work remains to bring this vision to fruition, and the National Institutes of Health continues to look to the diverse scientific community, from mathematics, to physics, chemistry, engineering, neuroethics, and neuroscience, to ensure that the greatest scientific benefit arises from this unique research Initiative.

Neuroepigenomics: Resources, Obstacles, and Opportunities.

Long-lived post-mitotic cells, such as the majority of human neurons, must respond effectively to ongoing changes in neuronal stimulation or microenvironmental cues through transcriptional and epigenomic regulation of gene expression. The role of epigenomic regulation in neuronal function is of fundamental interest to the neuroscience community, as these types of studies have transformed our understanding of gene regulation in post-mitotic cells. This perspective article highlights many of the resources available to researchers interested in neuroepigenomic investigations and discusses some of the current obstacles and opportunities in neuroepigenomics.

Community resources and technologies developed through the NIH Roadmap Epigenomics Program.

This chapter describes resources and technologies generated by the NIH Roadmap Epigenomics Program that may be useful to epigenomics researchers investigating a variety of diseases including cancer. Highlights include reference epigenome maps for a wide variety of human cells and tissues, the development of new technologies for epigenetic assays and imaging, the identification of novel epigenetic modifications, and an improved understanding of the role of epigenetic processes in a diversity of human diseases. We also discuss future needs in this area including exploration of epigenomic variation between individuals, single-cell epigenomics, environmental epigenomics, exploration of the use of surrogate tissues, and improved technologies for epigenome manipulation.

Outcome measures for clinical trials in fragile X syndrome.

OBJECTIVE: Progress in basic neuroscience has led to identification of molecular targets for treatment in fragile X syndrome (FXS) and other neurodevelopmental disorders; however, there is a gap in translation to targeted therapies in humans. One major obstacle to the demonstration of efficacy in human trials has been the lack of generally accepted endpoints to assess improvement in function in individuals with FXS. To address this problem, the National Institutes of Health convened a meeting of leading scientists and clinicians with the goal of identifying and standardizing outcome measures for use as potential endpoints in clinical trials in FXS. METHODS: Participants in the meeting included FXS experts, experts in the design and implementation of clinical trials and measure development, and representatives from advocacy groups, industry, and federal agencies. RESULTS: The group generated recommendations for optimal outcome measures in cognitive, behavioral, and biomarker/medical domains, including additional testing and validation of existing measures and development of new measures in areas of need. Although no one endpoint or set of endpoints could be identified that met all criteria as an optimal measure, recommendations are presented in this report. CONCLUSION: The report is expected to guide the selection of measures in clinical trials and lead to the use of a more consistent battery of measures across trials. Furthermore, this will help to direct research toward gaps in the development of validated FXS-specific outcome measures and to assist with interpretation of clinical trial data by creating templates for measurement of treatment efficacy.

Epigenetics in the nervous system.

It is becoming increasingly clear that epigenetic modifications are critical factors in the regulation of gene expression. With regard to the nervous system, epigenetic alterations play a role in a diverse set of processes and have been implicated in a variety of disorders. Gaining a more complete understanding of the essential components and underlying mechanisms involved in epigenetic regulation could lead to novel treatments for a number of neurological and psychiatric conditions.

Corticosterone response to acute stress in a mouse model of Fragile X syndrome.

Fragile X syndrome (FXS), the most common form of inherited mental retardation, results from the silencing of the Fmr1 gene that encodes the Fragile X mental retardation protein (FMRP). Because (1) mRNA for the glucocorticoid receptor is bound by FMRP and (2) the response to acute stress is elevated in children with FXS, we examined whether this heightened response is characteristic of a mouse model of FXS. Fmr1 knockout (KO) and wildtype (WT) control mice were exposed to 30 min of acute restraint; serum corticosterone levels were assayed from unstressed animals and those examined either immediately following stress or after a 15 or 60 min recovery period. Under unstressed conditions, KOs and WTs did not differ in serum corticosterone, although both genotype and sex affected corticosterone levels observed following exposure to acute stress. Similar to FXS patients, serum glucocorticoid levels of KO mice exhibited a protracted return to baseline following acute stress. This suggests that the stress response is misregulated in Fmr1 KO mice as in FXS patients and provides the first evidence for a link between a particular FMRP-binding mRNA and a functional phenotype of FXS (impaired glucocorticoid negative feedback).

Correlates across the structural, functional, and molecular phenotypes of fragile X syndrome.

Fragile X syndrome (FXS) is characterized by a pattern of morphological, functional, and molecular characteristics with, in at least some cases, apparent relationships among phenotypic features at different levels. Gross morphology differences in the sizes of some human brain regions are accompanied by fine structural alterations in the shapes and in the numbers of dendritic spines in both humans and the knockout mouse model. The excess number of spines, their immature appearance, and the impaired withdrawal of inappropriately oriented dendrites in FXS or the mouse model suggest impairment of neuronal maturation, including dendritic and spine pruning. It is not clear how these differences arise, although regionally or globally impaired translation of the mRNAs that interact with the Fmr1 protein product, FMRP, in the vicinity of the synapse, including genes involved in synapse development and plasticity and dendritic retraction, is certainly plausible. FMRP binds mRNA and may be involved in both transport and translation of the mRNAs it binds. The mRNAs it binds belong to multiple functional classes, apparently indicating that FMRP may impact multiple cellular processes. In one example, the glucocorticoid receptor, whose mRNA binds FMRP, regulates the stress-sensitive glucocorticosteroids. Both human FXS and the mouse model exhibit a protracted elevation in glucocorticosteroids after stress. Possible relationships of other genes to morphological and functional characteristics of FXS are also discussed.

RNA cargoes associating with FMRP reveal deficits in cellular functioning in Fmr1 null mice.

The Fragile X mental retardation-1 (Fmr1) gene encodes a multifunctional protein, FMRP, with intrinsic RNA binding activity. We have developed an approach, antibody-positioned RNA amplification (APRA), to identify the RNA cargoes associated with the in vivo configured FMRP messenger ribonucleoprotein (mRNP) complex. Using APRA as a primary screen, putative FMRP RNA cargoes were assayed for their ability to bind directly to FMRP using traditional methods of assessing RNA-protein interactions, including UV-crosslinking and filter binding assays. Approximately 60% of the APRA-defined mRNAs directly associate with FMRP. By examining a subset of these mRNAs and their encoded proteins in brain tissue from Fmr1 knockout mice, we have observed that some of these cargoes as well as the proteins they encode show discrete changes in abundance and/or differential subcellular distribution. These data are consistent with spatially selective regulation of multiple biological pathways by FMRP.

Effects of Fragile X syndrome and an FMR1 knockout mouse model on forebrain neuronal cell biology.

The neurological deficits exhibited by patients with Fragile X syndrome (FraX) have been attributed to the absence of the Fragile X Mental Retardation Protein (FMRP), the product of the FMR1 gene, which is nonfunctional in these individuals. While a great deal has been learned about FraX using non-invasive techniques and autopsy tissue from humans, the limited availability of subjects and specimens severely restricts the rate at which such data can be collected and the types of experimental questions posed. In view of these limitations, a transgenic mouse model of FraX has been constructed in which the FMR1 gene is selectively knocked out (KO) [Bakker et al. (1994) Cell 78:23-33]. These mice show molecular, morphological, and behavioral alterations consistent with phenotypes observed in FraX patients, making them good models to study the absence of FMRP expression.

Poly(A) tail length-dependent stabilization of GAP-43 mRNA by the RNA-binding protein HuD.

The neuronal ELAV-like RNA-binding protein HuD binds to a regulatory element in the 3'-untranslated region of the growth-associated protein-43 (GAP-43) mRNA. Here we report that overexpression of HuD protein in PC12 cells stabilizes the GAP-43 mRNA by delaying the onset of mRNA degradation and that this process depends on the size of the poly(A) tail. Using a polysome-based in vitro mRNA decay assay, we found that addition of recombinant HuD protein to the system increased the half-life of full-length, capped, and polyadenylated GAP-43 mRNA and that this effect was caused in part by a decrease in the rate of deadenylation of the mRNA. This stabilization was specific for GAP-43 mRNA containing the HuD binding element in the 3'-untranslated region and a poly(A) tail of at least 150 A nucleotides. In correlation with the effect of HuD on GAP-43 mRNA stability, we found that HuD binds GAP-43 mRNAs with long tails (A150) with 10-fold higher affinity than to those with short tails (A30). We conclude that HuD stabilizes the GAP-43 mRNA through a mechanism that is dependent on the length of the poly(A) tail and involves changes in its affinity for the mRNA.