Wireless tools for neuromodulation

Epilepsy is a spectrum of diseases characterized by recurrent seizures. It is estimated that 50 million individuals worldwide are affected and 30% of cases are medically refractory or drug resistant. Vagus nerve stimulation (VNS) and deep brain stimulation (DBS) are the only FDA approved device based therapies. Neither therapy offers complete seizure freedom in a majority of users. Novel methodologies are needed to better understand mechanisms and chronic nature of epilepsy. Most tools for neuromodulation in rodents are tethered. The few wireless devices use batteries or are inductively powered. The tether restricts movement, limits behavioral tests, and increases the risk of infection. Batteries are large and heavy with a limited lifetime. Inductive powering suffers from rapid efficiency drops due to alignment mismatches and increased distances. Miniature wireless tools that offer behavioral freedom, data acquisition, and stimulation are needed. This dissertation presents a platform of electrical, optical and radiofrequency (RF) technologies for device based neuromodulation. The platform can be configured with features including: two channels differential recording, one channel electrical stimulation, and one channel optical stimulation. Typical device operation consumes less than 4 mW. The analog front end has a bandwidth of 0.7 Hz - 1 kHz and a gain of 60 dB, and the constant current driver provides biphasic electrical stimulation. For use with optogenetics, the deep brain optical stimulation module provides 27 mW/mm2 of blue light (473 nm) with 21.01 mA. Pairing of stimulating and recording technologies allows closed-loop operation. A wireless powering cage is designed using the resonantly coupled filter energy transfer (RCFET) methodology. RF energy is coupled through magnetic resonance. The cage has a PTE ranging from 1.8-6.28% for a volume of 11 x 11 x 11 in3. This is sufficient to chronically house subjects. The technologies are validated through various in vivo preparations. The tools are designed to study epilepsy, SUDEP, and urinary incontinence but can be configured for other studies. The broad application of these technologies can enable the scientific community to better study chronic diseases and closed-loop therapies

Why Internal Moral Enhancement Might Be politically Better than External Moral Enhancement

Technology could be used to improve morality but it could do so in different ways. Some technologies could augment and enhance moral behaviour externally by using external cues and signals to push and pull us towards morally appropriate behaviours. Other technologies could enhance moral behaviour internally by directly altering the way in which the brain captures and processes morally salient information or initiates moral action. The question is whether there is any reason to prefer one method over the other? In this article, I argue that there is. Specifically, I argue that internal moral enhancement is likely to be preferable to external moral enhancement, when it comes to the legitimacy of political decision-making processes. In fact, I go further than this and argue that the increasingly dominant forms of external moral enhancement may already be posing a significant threat to political legitimacy, one that we should try to address. Consequently, research and development of internal moral enhancements should be prioritised as a political project

Mild guanidinoacetate increase under partial guanidinoacetate methyltransferase deficiency strongly affects brain cell development.

Among cerebral creatine deficiency syndromes, guanidinoacetate methyltransferase (GAMT) deficiency can present the most severe symptoms, and is characterized by neurocognitive dysfunction due to creatine deficiency and accumulation of guanidinoacetate in the brain. So far, every patient was found with negligible GAMT activity. However, GAMT deficiency is thought under-diagnosed, in particular due to unforeseen mutations allowing sufficient residual activity avoiding creatine deficiency, but enough guanidinoacetate accumulation to be toxic. With poorly known GAA-specific neuropathological mechanisms, we developed an RNAi-induced partial GAMT deficiency in organotypic rat brain cell cultures. As expected, the 85% decrease of GAMT protein was insufficient to cause creatine deficiency, but generated guanidinoacetate accumulation causing axonal hypersprouting and decrease in natural apoptosis, followed by induction of non-apoptotic cell death. Specific guanidinoacetate-induced effects were completely prevented by creatine co-treatment. We show that guanidinoacetate accumulation without creatine deficiency is sufficient to affect CNS development, and suggest that additional partial GAMT deficiencies, which may not show the classical brain creatine deficiency, may be discovered through guanidinoacetate measurement

Virtual Clinical Trials: One Step Forward, Two Steps Back

Virtual clinical trials have entered the medical research landscape. Today’s clinical trials recruit subjects online, obtain informed consent online, send treatments such as medications or devices to the subjects’ homes, and require subjects to record their responses online. Virtual clinical trials could be a way to democratize clinical research and circumvent geographical limitations by allowing access to clinical research for people who live far from traditional medical research centers. But virtual clinical trials also depart dramatically from traditional medical research studies in ways that can harm individuals and the public at large. This article addresses the issues presented by virtual clinical trials with regard to: (1) recruitment methods; (2) informed consent; (3) confidentiality; (4) potential risks to the subjects; and (5) the safety and efficacy of treatments that are approved

The spatio-temporal segregation of GAD forms defines distinct GABA signaling functions in the developing mouse olfactory system and provides novel insights into the origin and migration of GnRH neurons.

GABA (gamma-aminobutyric acid) has a dual role as an inhibitory neurotransmitter in the adult central nervous system (CNS) and as a signaling molecule exerting largely excitatory actions during development. The rate-limiting step of GABA synthesis is catalyzed by two glutamic acid decarboxylase isoforms GAD65 and GAD67 co-expressed in the GABAergic neurons of the CNS. Here we report that the two GADs show virtually non-overlapping expression patterns consistent with distinct roles in the developing peripheral olfactory system. GAD65 is expressed exclusively in undifferentiated neuronal progenitors confined to the proliferative zones of the sensory vomeronasal and olfactory epithelia. In contrast GAD67 is expressed in a subregion of the non-sensory epithelium/vomeronasal organ epithelium containing the putative GnRH progenitors and GnRH neurons migrating from this region through the frontonasal mesenchyme (FNM) into the basal forebrain. Only GAD67+, but not GAD65+ cells accumulate detectable GABA. We further demonstrate that GAD67 and its embryonic splice variant EGAD concomitant with GnRH are dynamically regulated during GnRH neuronal migration in vivo and in two immortalized cell lines representing migratory (GN11) and post-migratory (GT1-7) stage GnRH neurons, respectively. Analysis of GAD65/67 single and double knock-out (KO) embryos revealed that the two GADs play complementary (inhibitory) roles in GnRH migration ultimately modulating the speed and/or direction of GnRH migration. Our results also suggest that GAD65 and GAD67/EGAD characterized by distinct subcellular localization and kinetics have disparate functions during olfactory system development mediating proliferative and migratory responses putatively through specific subcellular GABA pools. (c) 2014 Wiley Periodicals, Inc. Develop Neurobiol, 2014

Trust and Transparency in Artificial Intelligence. Ethics & Society Opinion. European Commission

The Ethics and Society Subproject has developed this Opinion in order to clarify lessons the Human Brain Project (HBP) can draw from the current discussion of artificial intelligence, in particular the social and ethical aspects of AI, and outline areas where it could usefully contribute. The EU and numerous other bodies are promoting and implementing a wide range of policies aimed to ensure that AI is beneficial - that it serves society. The HBP as a leading project bringing together neuroscience and ICT is in an excellent position to contribute to and to benefit from these discussions. This Opinion therefore highlights some key aspects of the discussion, shows its relevance to the HBP and develops a list of six recommendations

Disruption of Cell-Cell Adhesion Codes Underlies the Unique X-linked Inheritance Pattern of Protocadherin 19 Girls Clustering Epilepsy

Epilepsy is a disease of the central nervous system (CNS) caused by increased neuronal activity resulting in seizures and often loss of consciousness. Epilepsy can result from both traumas to the brain or a genetic predisposition. Recent advances in DNA sequencing technology has identified many forms of epilepsy caused by mutations in single genes. Although such monogenic epilepsies are rare, investigating their underlying molecular mechanisms provides important insights into pathways and processes that cause seizures and assists in the application of pharmacotherapy and surgical strategies. The second most common form of monogenic epilepsy is Protocadherin 19 Girls Clustering Epilepsy (PCDH19-GCE) caused by mutation of the X-linked gene PCDH19. This disorder is characterised by clusters of febrile seizures beginning in early childhood that is often accompanied by variable intellectual disability and autism spectrum disorder. The most striking feature of PCDH19-GCE is its unique X-linked inheritance pattern; heterozygous females with PCDH19 mutations are affected whereas hemizygous males are not. It is hypothesised that the mixture of PCDH19-WT and PCDH19-mutant neurons (generated by random X-inactivation in female brains) causes abnormal neuronal connections leading to disease. However, there is no experimental evidence supporting this hypothesis and the cellular and molecular mechanisms underpinning this unique inheritance pattern are unknown. To better understand how mutation of PCDH19 leads to the unique X-linked inheritance pattern this thesis uses a Pcdh19 null mouse, cell culture assays and unique CRISPR-Cas9 engineered mouse models. It is shown that heterozygous and homozygous deletion of Pcdh19 in mice does not cause any gross brain morphological abnormalities and that Pcdh19 null neurons are present within the correct layers in the cortex despite their slight increase in migration potential in vitro. Using cultured K562 cells it is shown that PCDH19 and other non-clustered (NC) PCDH members contribute to combinatorial adhesion codes that dictate specific cell-cell interactions. Similarly, mosaic expression of Pcdh19 in heterozygous mice leads to abnormal cell sorting in the developing cortex such that cells separate into PCDH19 positive and negative patches, correlating with altered brain network activity consistent with changes that can underlie seizures in adult mice. Deletion of Pcdh19 in heterozygous embryos using CRISPR-Cas9 technology eliminates this incompatibility of adhesion codes and prevents abnormal cell sorting from occurring. In addition, variable cortical folding malformations in PCDH19-GCE epilepsy patients were identified. Collectively these results highlight the role of PCDH19 in determining specific adhesion codes during brain development and how disruption of these codes is associated with the unique X-linked inheritance pattern of PCDH19-GCE. Importantly, a framework is provided for investigating how this abnormal neuronal segregation phenotype leads to seizures and cognitive deficits.Thesis (Ph.D.) -- University of Adelaide, School of Biological Sciences, 201

Identification of neural oscillations and epileptiform changes in human brain organoids

Brain organoids represent a powerful tool for studying human neurological diseases, particularly those that affect brain growth and structure. However, many diseases manifest with clear evidence of physiological and network abnormality in the absence of anatomical changes, raising the question of whether organoids possess sufficient neural network complexity to model these conditions. Here, we explore the network-level functions of brain organoids using calcium sensor imaging and extracellular recording approaches that together reveal the existence of complex network dynamics reminiscent of intact brain preparations. We demonstrate highly abnormal and epileptiform-like activity in organoids derived from induced pluripotent stem cells from individuals with Rett syndrome, accompanied by transcriptomic differences revealed by single-cell analyses. We also rescue key physiological activities with an unconventional neuroregulatory drug, pifithrin-α. Together, these findings provide an essential foundation for the utilization of brain organoids to study intact and disordered human brain network formation and illustrate their utility in therapeutic discovery