Neuroethics guidance documents: principles, analysis, and implementation strategies

Innovations in neurotechnologies have ignited conversations about ethics around the world, with implications for researchers, policymakers, and the private sector. The human rights impacts of neurotechnologies have drawn the attention of United Nations bodies; nearly 40 states are tasked with implementing the Organization for Economic Co-operation and Development's principles for responsible innovation in neurotechnology; and the United States is considering placing export controls on brain-computer interfaces. Against this backdrop, we offer the first review and analysis of neuroethics guidance documents recently issued by prominent government, private, and academic groups, focusing on commonalities and divergences in articulated goals; envisioned roles and responsibilities of different stakeholder groups; and the suggested role of the public. Drawing on lessons from the governance of other emerging technologies, we suggest implementation and evaluation strategies to guide practitioners and policymakers in operationalizing these ethical norms in research, business, and policy settings.

Assessing the Perceived Value of Neuroethics Questions and Policy to Neuro-Entrepreneurs

Neuroscience and its findings have deep personal and cultural meaning, so the implications of brain science raise new flavors of ethical issues not covered by traditional bioethics. The field of neuroethics bridges this gap, addressing and responding to the ethical, legal, and social issues intimately related to the evolving landscape of neuroscience. Neuroethical concerns have registered at the highest levels of government. In 2018, an interdisciplinary global neuroethics group working with leading scientists from the International Brain Initiative, a consortium of seven large-scale national-level brain research projects around the globe, published “Neuroethics Questions to Guide Ethical Research in the International Brain Initiatives.” The document provides guiding questions to consider throughout the lifecycle of neuroscience research. These questions tackle issues such as identity, morality, cross-cultural differences, privacy, and potential stakeholder involvement in ethical decision-making. In our work with the International Brain Initiative, we noted the important role that the private sector will play in translating and scaling neuroscience for society. We also noticed a gap in communication and collaboration between government, academia and the private sector. These guiding questions were largely co-created with policy makers and academics, so it was unclear how these issues might be received by neuro-entrepreneurs and neuro-industry. We hoped to identify not only common concerns, but also a common language for discussing neuroethical issues with stakeholders outside of government and academia. We used empirical ethics methods to assess the perceived value and attitudes of neuro-entrepreneurs toward neuroethical issues and whether or not these issues align with the process of neuro-innovation. We conducted one-on-one structured interviews with 21 neuro-entrepreneurs in the private sector and used two independent reviewers to analyze for themes. From this preliminary research, we identified key neuroethical themes and processual pain points of neurotech entrepreneurs throughout the innovation process. We also provide a preliminary neuroethics needs assessment for neuro-industry and suggest avenues through which neuroethicists can work with neurotech leadership to build an ethically aligned future. Overall, we hope to raise awareness and provide actionable steps toward advancing and accelerating societally impactful neuroscience.

Stigma and functional neurological disorder: a research agenda targeting the clinical encounter

Stigma against patients with functional neurological disorder (FND) presents obstacles to diagnosis, treatment, and research. The lack of biomarkers and the potential for symptoms to be misunderstood, invalidated, or dismissed can leave patients, families, and healthcare professionals at a loss. Stigma exacerbates suffering and unmet needs of patients and families, and can result in poor clinical management and prolonged, repetitive use of healthcare resources. Our current understanding of stigma in FND comes from surveys documenting frustration experienced by providers and distressing healthcare interactions experienced by patients. However, little is known about the origins of FND stigma, its prevalence across different healthcare contexts, its impact on patient health outcomes, and optimal methods for reduction. In this paper, we set forth a research agenda directed at better understanding the prevalence and context of stigma, clarifying its impact on patients and providers, and promoting best practices for stigma reduction.

Outcome measurement in functional neurological disorder: a systematic review and recommendations

OBJECTIVES

We aimed to identify existing outcome measures for functional neurological disorder (FND), to inform the development of recommendations and to guide future research on FND outcomes.

METHODS

A systematic review was conducted to identify existing FND-specific outcome measures and the most common measurement domains and measures in previous treatment studies. Searches of Embase, MEDLINE and PsycINFO were conducted between January 1965 and June 2019. The findings were discussed during two international meetings of the FND-Core Outcome Measures group.

RESULTS

Five FND-specific measures were identified-three clinician-rated and two patient-rated-but their measurement properties have not been rigorously evaluated. No single measure was identified for use across the range of FND symptoms in adults. Across randomised controlled trials (k=40) and observational treatment studies (k=40), outcome measures most often assessed core FND symptom change. Other domains measured commonly were additional physical and psychological symptoms, life impact (ie, quality of life, disability and general functioning) and health economics/cost-utility (eg, healthcare resource use and quality-adjusted life years).

CONCLUSIONS

There are few well-validated FND-specific outcome measures. Thus, at present, we recommend that existing outcome measures, known to be reliable, valid and responsive in FND or closely related populations, are used to capture key outcome domains. Increased consistency in outcome measurement will facilitate comparison of treatment effects across FND symptom types and treatment modalities. Future work needs to more rigorously validate outcome measures used in this population.

The NIH BRAIN Initiative: Integrating Neuroethics and Neuroscience

The NIH Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative is focused on developing new tools and neurotechnologies to transform our understanding of the brain, and neuroethics is an essential component of this research effort. Coordination with other brain projects around the world will help maximize success.

Neuroethics and the NIH BRAIN Initiative

The Brain Research through Advancing Innovative Neurotechnologies® (BRAIN) Initiative is focused on developing new tools and neurotechnologies to revolutionize our understanding of how the brain functions in health and disease, in large part to address the growing societal impact of neurological, mental health, and substance abuse disorders. Recent advances in neurotechnology are delivering unprecedented ways to interrogate and modulate brain function, and the BRAIN Initiative is focused on translation for human medical uses over the next decade. Since its inception, the NIH component of the BRAIN Initiative has utilized an iterative model of integrating ethics into the scientific trajectory of the Initiative, most recently with the creation of a Neuroethics Division of the NIH BRAIN Initiative Multi-Council Working Group. The Division serves as a resource of expertise, to help the BRAIN Initiative navigate issues involving ethics. Here we discuss the BRAIN Initiative, and its implications and aspirations for neuroethics. We also discuss new opportunities for collaboration and for integrating stakeholder voices.

Disentangling Stigma from Functional Neurological Disorders: Conference Report and Roadmap for the Future

A multidisciplinary expert review of key issues and future directions from the conference “Controversial labels and clinical uncertainties: psychogenic disorders, conversion disorder, and functional symptoms.”

On October 9 and 10, 2015, a conference entitled “Controversial labels and clinical uncertainties: psychogenic disorders, conversion disorder, and functional symptoms” was held at the Center for Ethics, Emory University, Atlanta, GA, USA. This conference brought together a select group of 30 distinguished thought leaders and practitioners, including ethicists, researchers, clinicians, humanities scholars, and advocates to discuss the unique challenges and controversies related to the diagnosis, treatment, and stigma for patients with what is currently recognized as functional (“psychogenic”) neurological disorders. Our group of experts explored the conflicts and ethical tensions within health care that must be addressed in order to advance care for these disorders. What follows is a reflection on the conversations between conference attendees outlining key challenges and value conflicts in the diagnosis and treatment of patients with functional disorders. With this report, we aim to provide a roadmap for reducing stigma and improving care for functional neurological disorders (FND). A path forward would involve (1) setting a multifactorial research agenda that equally prioritized access to effective psychotherapy as well as identification of novel biomarkers; (2) empowering patients with FND to be heard and to drive changes in care; and (3) reducing isolation for clinicians by providing formal training and setting up multidisciplinary care teams and support networks.

Noradrenergic regulation of plasticity marker expression in the adult rodent piriform cortex

The adult rodent piriform cortex has been reported to harbor immature neurons that express markers associated with neurodevelopment and plasticity, namely polysialylated neural cell adhesion molecule (PSA-NCAM) and doublecortin (DCX). We characterized the expression of PSA-NCAM and DCX across the rostrocaudal axis of the rat piriform cortex and observed higher numbers of PSA-NCAM and DCX positive cells in the posterior subdivision. As observed in the rat piriform cortex, Nestin-GFP reporter mice also revealed a similar gradient of GFP-positive cells with an increasing rostro-caudal gradient of expression. Given the extensive noradrenergic innervation of the piriform cortex and its role in regulating piriform cortex function and synaptic plasticity, we addressed the influence of norepinephrine (NE) on piriform cortex plasticity marker expression. Depletion of NE by treatment with the noradrenergic neurotoxin DSP-4 significantly increased the number of DCX and PSA-NCAM immunopositive cells in the piriform cortex of adult rats. Similarly, DSP-4 treated Nestin-GFP reporter mice revealed a robust induction of GFP-positive cells within the piriform cortex following NE depletion. Genetic loss of NE in dopamine β-hydroxylase knockout (Dbh -/-) mice phenocopied the effects of DSP-4, with an increase noted in PSA-NCAM and DCX positive cells in the piriform cortex. Further, chronic α₂-adrenergic receptor stimulation with the agonist guanabenz increased PSA-NCAM and DCX positive cells in the piriform cortex of adult rats and GFP-positive cells in the piriform cortex of Nestin-GFP mice. By contrast, chronic α₂-adrenergic receptor blockade with the antagonist yohimbine reduced PSA-NCAM and DCX positive cells in the piriform cortex of adult rats. Our results provide novel evidence for a role of NE in regulating the expression of plasticity markers, including PSA-NCAM, DCX, and nestin, within the adult mouse and rat piriform cortex.

The role of placebo in the diagnosis and treatment of functional neurologic disorders

Placebo therapy can produce meaningful, clinical relief for a variety of conditions. While placebos are not without their ethically fraught history, they continue to be used, largely covertly, even today. Because the prognosis for psychogenic disorders is often poor and recovery may be highly dependent on the patient's belief in the diagnosis and treatment regimen, some physicians find placebo therapy for psychogenic disorders compelling, but also particularly contentious. Yet placebos also have a long tradition of being used for provocative diagnosis (wherein placebo is used to elicit and/or terminate the symptoms as a way of diagnosing symptoms as "psychogenic"). In this chapter we discuss cases describing placebo as therapy for psychogenic disorders and the challenges related to embedded Cartesian beliefs in Western medicine. The legitimate ethical reservations against placebo therapy, in general, have been related to assumptions about their "inertness" and a requirement for deception, both which are being refuted by emerging data. In this chapter, we also re-evaluate the concerns associated with placebo therapy for psychogenic disorders by asking, "Are we harming patients by withholding placebo treatment?"

Localization and function of dopamine receptors in the subthalamic nucleus of normal and parkinsonian monkeys

The subthalamic nucleus (STN) receives a dopaminergic innervation from the substantia nigra pars compacta, but the role of this projection remains poorly understood, particularly in primates. To address this issue, we used immuno-electron microscopy to localize D1, D2, and D5 dopamine receptors in the STN of rhesus macaques and studied the electrophysiological effects of activating D1-like or D2-like receptors in normal and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated parkinsonian monkeys. Labeling of D1 and D2 receptors was primarily found presynaptically, on preterminal axons and putative glutamatergic and GABAergic terminals, while D5 receptors were more significantly expressed postsynaptically, on dendritic shafts of STN neurons. The electrical spiking activity of STN neurons, recorded with standard extracellular recording methods, was studied before, during, and after intra-STN administration of the dopamine D1-like receptor agonist SKF82958, the D2-like receptor agonist quinpirole, or artificial cerebrospinal fluid (control injections). In normal animals, administration of SKF82958 significantly reduced the spontaneous firing but increased the rate of intraburst firing and the proportion of pause-burst sequences of firing. Quinpirole only increased the proportion of such pause-burst sequences in STN neurons of normal monkeys. In MPTP-treated monkeys, the D1-like receptor agonist also reduced the firing rate and increased the proportion of pause-burst sequences, while the D2-like receptor agonist did not change any of the chosen descriptors of the firing pattern of STN neurons. Our data suggest that dopamine receptor activation can directly modulate the electrical activity of STN neurons by pre- and postsynaptic mechanisms in both normal and parkinsonian states, predominantly via activation of D1 receptors.

Guidelines for the ethical use of neuroimages in medical testimony: report of a multidisciplinary consensus conference

SUMMARY

With rapid advances in neuroimaging technology, there is growing concern over potential misuse of neuroradiologic imaging data in legal matters. On December 7 and 8, 2012, a multidisciplinary consensus conference, Use and Abuse of Neuroimaging in the Courtroom, was held at Emory University in Atlanta, Georgia. Through this interactive forum, a highly select group of experts-including neuroradiologists, neurologists, forensic psychiatrists, neuropsychologists, neuroscientists, legal scholars, imaging statisticians, judges, practicing attorneys, and neuroethicists-discussed the complex issues involved in the use of neuroimaging data entered into legal evidence and for associated expert testimony. The specific contexts of criminal cases, child abuse, and head trauma were especially considered. The purpose of the conference was to inform the development of guidelines on expert testimony for the American Society of Neuroradiology and to provide principles for courts on the ethical use of neuroimaging data as evidence. This report summarizes the conference and resulting recommendations.

Selective loss of noradrenaline exacerbates early cognitive dysfunction and synaptic deficits in APP/PS1 mice

BACKGROUND

Degeneration of the locus coeruleus (LC), the major noradrenergic nucleus in the brain, occurs early and is ubiquitous in Alzheimer's disease (AD). Experimental lesions to the LC exacerbate AD-like neuropathology and cognitive deficits in several transgenic mouse models of AD. Because the LC contains multiple neuromodulators known to affect amyloid β toxicity and cognitive function, the specific role of noradrenaline (NA) in AD is not well understood.

METHODS

To determine the consequences of selective NA deficiency in an AD mouse model, we crossed dopamine β-hydroxylase (DBH) knockout mice with amyloid precursor protein (APP)/presenilin-1 (PS1) mice overexpressing mutant APP and PS1. Dopamine β-hydroxylase (-/-) mice are unable to synthesize NA but otherwise have normal LC neurons and co-transmitters. Spatial memory, hippocampal long-term potentiation, and synaptic protein levels were assessed.

RESULTS

The modest impairments in spatial memory and hippocampal long-term potentiation displayed by young APP/PS1 or DBH (-/-) single mutant mice were augmented in DBH (-/-)/APP/PS1 double mutant mice. Deficits were associated with reduced levels of total calcium/calmodulin-dependent protein kinase II and N-methyl-D-aspartate receptor 2A and increased N-methyl-D-aspartate receptor 2B levels and were independent of amyloid β accumulation. Spatial memory performance was partly improved by treatment with the NA precursor drug L-threo-dihydroxyphenylserine.

CONCLUSIONS

These results indicate that early LC degeneration and subsequent NA deficiency in AD may contribute to cognitive deficits via altered levels of calcium/calmodulin-dependent protein kinase II and N-methyl-D-aspartate receptors and suggest that NA supplementation could be beneficial in early AD.

Extrastriatal D2-like receptors modulate basal ganglia pathways in normal and Parkinsonian monkeys

According to traditional models of the basal ganglia-thalamocortical network of connections, dopamine exerts D2-like receptor (D2LR)-mediated effects through actions on striatal neurons that give rise to the "indirect" pathway, secondarily affecting the activity in the internal and external pallidal segments (GPi and GPe, respectively) and the substantia nigra pars reticulata (SNr). However, accumulating evidence from the rodent literature suggests that D2LR activation also directly influences synaptic transmission in these nuclei. To further examine this issue in primates, we combined in vivo electrophysiological recordings and local intracerebral microinjections of drugs with electron microscopic immunocytochemistry to study D2LR-mediated modulation of neuronal activities in GPe, GPi, and SNr of normal and MPTP-treated (parkinsonian) monkeys. D2LR activation with quinpirole increased firing in most GPe neurons, likely due to a reduction of striatopallidal GABAergic inputs. In contrast, local application of quinpirole reduced firing in GPi and SNr, possibly through D2LR-mediated effects on glutamatergic inputs. Injections of the D2LR antagonist sulpiride resulted in effects opposite to those of quinpirole in GPe and GPi. D2 receptor immunoreactivity was most prevalent in putative striatal-like GABAergic terminals and unmyelinated axons in GPe, GPi, and SNr, but a significant proportion of immunoreactive boutons also displayed ultrastructural features of glutamatergic terminals. Postsynaptic labeling was minimal in all nuclei. The D2LR-mediated effects and pattern of distribution of D2 receptor immunoreactivity were maintained in the parkinsonian state. Thus, in addition to their preferential effects on indirect pathway striatal neurons, extrastriatal D2LR activation in GPi and SNr also influences direct pathway elements in the primate basal ganglia under normal and parkinsonian conditions.

Extrastriatal dopaminergic circuits of the Basal Ganglia

The basal ganglia are comprised of the striatum, the external and internal segment of the globus pallidus (GPe and GPi, respectively), the subthalamic nucleus (STN), and the substantia nigra pars compacta and reticulata (SNc and SNr, respectively). Dopamine has long been identified as an important modulator of basal ganglia function in the striatum, and disturbances of striatal dopaminergic transmission have been implicated in diseases such as Parkinson's disease (PD), addiction and attention deficit hyperactivity disorder. However, recent evidence suggests that dopamine may also modulate basal ganglia function at sites outside of the striatum, and that changes in dopaminergic transmission at these sites may contribute to the symptoms of PD and other neuropsychiatric disorders. This review summarizes the current knowledge of the anatomy, functional effects and behavioral consequences of the dopaminergic innervation to the GPe, GPi, STN, and SNr. Further insights into the dopaminergic modulation of basal ganglia function at extrastriatal sites may provide us with opportunities to develop new and more specific strategies for treating disorders of basal ganglia dysfunction.

Light and electron microscopic localization of alpha-1 adrenergic receptor immunoreactivity in the rat striatum and ventral midbrain

Electrophysiological and pharmacological studies have demonstrated that alpha-1 adrenergic receptor (alpha1AR) activation facilitates dopamine (DA) transmission in the striatum and ventral midbrain. However, because little is known about the localization of alpha1ARs in dopaminergic regions, the substrate(s) and mechanism(s) underlying this facilitation of DA signaling are poorly understood. To address this issue, we used light and electron microscopy immunoperoxidase labeling to examine the cellular and ultrastructural distribution of alpha1ARs in the caudate putamen, nucleus accumbens, ventral tegmental area, and substantia nigra in the rat. Analysis at the light microscopic level revealed alpha1AR immunoreactivity mainly in neuropil, with occasional staining in cell bodies. At the electron microscopic level, alpha1AR immunoreactivity was found primarily in presynaptic elements, with scarce postsynaptic labeling. Unmyelinated axons and about 30-50% terminals forming asymmetric synapses contained the majority of presynaptic labeling in the striatum and midbrain, while in the midbrain a subset of terminals forming symmetric synapses also displayed immunoreactivity. Postsynaptic labeling was scarce in both striatal and ventral midbrain regions. On the other hand, only 3-6% of spines displayed alpha1AR immunoreactivity in the caudate putamen and nucleus accumbens. These data suggest that the facilitation of dopaminergic transmission by alpha1ARs in the mesostriatal system is probably achieved primarily by pre-synaptic regulation of glutamate and GABA release.

Norepinephrine: The redheaded stepchild of Parkinson's disease

Parkinson's disease (PD) affects approximately 1% of the world's aging population. Despite its prevalence and rigorous research in both humans and animal models, the etiology remains unknown. PD is most often characterized by the degeneration of dopamine (DA) neurons in the substantia nigra pars compacta (SNc), and models of PD generally attempt to mimic this deficit. However, PD is a true multisystem disorder marked by a profound but less appreciated loss of cells in the locus coeruleus (LC), which contains the major group of noradrenergic neurons in the brain. Historic and more recent experiments exploring the role of norepinephrine (NE) in PD will be analyzed in this review. First, we examine the evidence that NE is neuroprotective and that LC degeneration sensitizes DA neurons to damage. The second part of this review focuses on the potential contribution of NE loss to the behavioral symptoms associated with PD. We propose that LC loss represents a crucial turning point in PD progression and that pharmacotherapies aimed at restoring NE have important therapeutic potential.

Reduced MPTP toxicity in noradrenaline transporter knockout mice

The noradrenergic neurons of the locus coeruleus (LC) are damaged in Parkinson's disease (PD). Neurotoxin ablation of the LC noradrenergic neurons has been shown to exacerbate the dopaminergic toxicity of MPTP, suggesting that the noradrenergic system protects dopamine neurons. We utilized mice that exhibit elevated synaptic noradrenaline (NA) by genetically deleting the noradrenaline transporter (NET), a key regulator of the noradrenergic system (NET KO mice). NET KO and wild-type littermates were administered MPTP and striatal dopamine terminal integrity was assessed by HPLC of monoamines, immmunoblotting for dopaminergic markers and tyrosine hydroxylase (TH) immunohistochemistry. MPTP significantly reduced striatal dopamine in wild-type mice, but not in the NET KO mice. To confirm that the protection observed in the NET KO mice was due to the lack of NET, we treated wild-type mice with the specific NET inhibitor, nisoxetine, and then challenged them with MPTP. Nisoxetine conferred protection to the dopaminergic system. These data indicate that NA can modulate MPTP toxicity and suggest that manipulation of the noradrenergic system may have therapeutic value in PD.