Analysis of NINDS Health Disparities and Health Equity Research Portfolio, 2016-2020: Results and a Process for Transparency, Accuracy, and Reliability.

BACKGROUND AND OBJECTIVES: As detailed throughout this special issue, the National Institute of Neurological Disorders and Stroke (NINDS) recently undertook a strategic planning effort to guide the Institute's efforts and priorities in health disparities and health equity (HD/HE) research. One input into this effort was to conduct a 5-year longitudinal, in-depth analysis of NINDS-supported HD/HE research newly funded between the years 2016 and 2020. The goals of this analysis were to describe NINDS's portfolio according to consistent, contemporary definitions and HD/HE disciplinary theory. This required the development of a novel, systematic, and validated analysis protocol. The portfolio analysis was designed to inform the recommendations of an expert working group convened by the NINDS and internal efforts to support high-priority research, training, and infrastructure efforts. METHODS: NINDS staff developed and validated this HD/HE research portfolio analysis protocol. Ultimately, HD/HE projects were characterized by their disease focus, populations of study, the health equity determinant(s) addressed, and the type and phase of research being conducted. For all interventional research, there was further assessment of the type and setting of intervention delivery as well as utilization of evidence-based community engagement and intervention sustainability approaches. RESULTS: A total of 58 new HD/HE research projects were funded from 2016 to 2020. The results of the descriptive analysis described here help provide a holistic picture of NINDS's HD/HE research portfolio, revealing strengths and gaps in the portfolio as well as opportunities ripe for future investment. DISCUSSION: NINDS developed a standardized HD/HE research categorization methodology with imbedded quality control checks that is intended to be transparent, accurate, and reproducible. The results of this HD/HE research portfolio analysis will serve as a baseline from which to assess the success of NINDS's research investments going forward.

Examining trends in the diversity of the U.S. National Institutes of Health participating and funded workforce.

Here, we use recent U.S. National Institutes of Health (NIH) data to document trends in the NIH-funded workforce over time. Consistent with previous studies that were initiated by NIH, we find that the number of scientists funded on competing R01-equivalent (R01 Eq.) and research project grants (RPGs) increased 2-5% per year between 2009 and 2016. Primary beneficiaries of this growth were experienced investigators (Exp), whereas the share of funding awarded to early-stage investigators (ESIs) and new investigators (NIs) declined. The decline occurred even after NIH instituted the New and Early-Stage Investigator policy in 2009. When we evaluate the investigator pool, we find that women and racial and ethnic minorities represent a higher percentage of NIs and ESIs relative to Exp. Thus, trends of diminishing support for NIs and ESIs may negatively impact the diversity of the current and future biomedical research workforce. We find some recent gains among women and Hispanics as part of the applicant and awardee pool for both R01 Eq. and RPGs, but significant, large gaps persist among nationally underrepresented racial minorities. Our findings suggest a need to prioritize investments and support of ESIs and NIs, groups in which women and racial and ethnic minorities represent a larger proportion of the applicant pool, to enhance diversity in the NIH-funded workforce.-Nikaj, S., Roychowdhury, D., Lund, P. K., Matthews, M., Pearson, K. Examining trends in the diversity of the U.S. National Institutes of Health participating and funded workforce.

Research review: Functional brain connectivity and child psychopathology--overview and methodological considerations for investigators new to the field.

BACKGROUND: Functional connectivity MRI is an emerging technique that can be used to investigate typical and atypical brain function in developing and aging populations. Despite some of the current confounds in the field of functional connectivity MRI, the translational potential of the technique available to investigators may eventually be used to improve diagnosis, early disease detection, and therapy monitoring. METHOD AND SCOPE: Based on a comprehensive survey of the literature, this review offers an introduction of resting-state functional connectivity for new investigators to the field of resting-state functional connectivity. We discuss a brief history of the technique, various methods of analysis, the relationship of functional networks to behavior, as well as the translational potential of functional connectivity MRI to investigate neuropsychiatric disorders. We also address some considerations and limitations with data analysis and interpretation. CONCLUSIONS: The information provided in this review should serve as a foundation for investigators new to the field of resting-state functional connectivity. The discussion provides a means to better understand functional connectivity and its application to typical and atypical brain function.

Attention deficit hyperactivity disorder.

Over the last two decades, there have been numerous technical and methodological advances available to clinicians and researchers to better understand attention deficit hyperactivity disorder (ADHD) and its etiology. Despite the growing body of literature investigating the disorder's pathophysiology, ADHD remains a complex psychiatric disorder to characterize. This chapter will briefly review the literature on ADHD, with a focus on its history, the current genetic insights, neurophysiologic theories, and the use of neuroimaging to further understand the etiology. We address some of the major concerns that remain unclear about ADHD, including subtype instability, heterogeneity, and the underlying neural correlates that define the disorder. We highlight that the field of ADHD is rapidly evolving; the descriptions provided here will hopefully provide a sturdy foundation for which to build and improve our understanding of the disorder.

Reduced presynaptic dopamine activity in adolescent dorsal striatum.

Adolescence coincides with symptomatic onset of several psychiatric illnesses including schizophrenia and addiction. Excess limbic dopamine activity has been implicated in these vulnerabilities. We combined molecular and dynamic indices of dopamine neurotransmission to assess dopamine function in adolescent rats in two functionally distinct striatal subregions: nucleus accumbens (NAc) and dorsal striatum (DS). In adolescents, we find an overall reduction in dopamine availability selective to the DS. Dopamine release in the DS, but not in the NAc, was less responsive to amphetamine in adolescents compared to adults. The dopamine transporter (DAT) inhibitor, nomifensine, similarly inhibited basal and amphetamine-induced dopamine release in either regions of both the age groups, suggesting that the reduced effectiveness of amphetamine is not due to differences in DAT function. Furthermore, DAT and vesicular monoamine transporter-2 expressions were similar in the DS and NAc of adolescent rats. In contrast, expression of tyrosine hydroxylase (TH) was reduced in the DS, but not in the NAc, of adolescents compared to adults. Behaviorally, adolescents were less sensitive to amphetamine but more sensitive to a TH inhibitor. These data indicate that, in contrast to the general notion that dopamine is hyperactive in adolescents, there is diminished presynaptic dopamine activity in adolescents that is selective to the DS and may result from attenuated TH activity. Given recent reports of altered dopamine activity in associative/dorsal striatum of individuals at a clinically high risk of psychosis, our data further support the idea that dorsal, as opposed to ventral, regions of the striatum are a locus of vulnerability for psychosis.

Glutamatergic animal models of schizophrenia.

Dysregulation of glutamate neurotransmission has been implicated in schizophrenia primarily because antagonists of the n-methyl-d-aspartate (NMDA) subtype of glutamate receptors exacerbate preexisting symptoms of schizophrenia in patients and produce behavioral disruptions that resemble some symptoms of schizophrenia in healthy individuals. Given this, NMDA receptor antagonists have been used extensively to model aspects of the disease in laboratory animals and have provided a useful preclinical tool for testing novel treatment strategies. More recent genetic and postmortem findings have implicated proteins other than the NMDA receptor in the pathophysiology of schizophrenia which play a role in regulation of the glutamate synapse. Animal models developed based on these findings have the potential of increasing our mechanistic understanding of the disease. Here we review some of the pertinent literature related to pharmacological and genetic animal models of glutamate dysfunction in schizophrenia.

Putative γ-aminobutyric acid neurons in the ventral tegmental area have a similar pattern of plasticity as dopamine neurons during appetitive and aversive learning.

Dopamine influences affective, motor and cognitive processing, and multiple forms of learning and memory. This multifaceted functionality, which operates across long temporal windows, is broader than the narrow and temporally constrained role often ascribed to dopamine neurons as reward prediction error detectors. Given the modulatory nature of dopamine neurotransmission, that dopamine release is activated by both aversive and appetitive stimuli, and that dopamine receptors are often localized extrasynaptically, a role for dopamine in transmitting precise error signals has been questioned. Here we recorded from ventral tegmental area (VTA) neurons, while exposing rats to novel stimuli that were predictive of an appetitive or aversive outcome in the same behavioral session. The VTA contains dopamine and -aminobutyric acid (GABA) neurons that project to striatal and cortical regions and are strongly implicated in learning and affective processing. The response of VTA neurons, regardless of whether they had putative dopamine or GABA waveforms, transformed flexibly as animals learned to associate novel stimuli from different sensory modalities to appetitive or aversive outcomes. Learning the appetitive association led to larger excitatory VTA responses, whereas acquiring the aversive association led to a biphasic response of brief excitation followed by sustained inhibition. These responses shifted rapidly as outcome contingencies changed. These data suggest that VTA neurons interface sensory information with representational memory of aversive and appetitive events. This pattern of plasticity was not selective for putative dopamine neurons and generalized to other cells, suggesting that the temporally precise information transfer from the VTA may be mediated by faster acting GABA neurons.