Parvalbumin-positive GABAergic interneurons (PV-INs) provide inhibitory control of excitatory neuron activity, coordinate circuit function, and regulate behavior and cognition. PV-INs are uniquely susceptible to loss and dysfunction in traumatic brain injury (TBI) and epilepsy but the cause of this susceptibility is unknown. One hypothesis is that PV-INs use specialized metabolic systems to support their high-frequency action potential firing and that metabolic stress disrupts these systems, leading to their dysfunction and loss. Metabolism-based therapies can restore PV-IN function after injury in preclinical TBI models. Based on these findings, we hypothesize that (1) PV-INs are highly metabolically specialized, (2) these specializations are lost after TBI, and (3) restoring PV-IN metabolic specializations can improve PV-IN function as well as TBI-related outcomes. Using novel single-cell approaches, we can now quantify cell-type-specific metabolism in complex tissues to determine whether PV-IN metabolic dysfunction contributes to the pathophysiology of TBI.

The nervous system orchestrates adaptive behaviors by intricately coordinating responses to internal cues and environmental stimuli. This involves integrating sensory input, managing competing motivational states, and drawing on past experiences to anticipate future outcomes. While traditional models attribute this complexity to interactions between the mesocorticolimbic system and hypothalamic centers, the specific nodes of integration have remained elusive. Recent research, including our own, sheds light on the midline thalamus's overlooked role in this process. We propose that the midline thalamus integrates internal states with memory and emotional signals to guide adaptive behaviors. Our investigations into midline thalamic neuronal circuits have provided crucial insights into the neural mechanisms behind flexibility and adaptability. Understanding these processes is essential for deciphering human behavior and conditions marked by impaired motivation and emotional processing. Our research aims to contribute to this understanding, paving the way for targeted interventions and therapies to address such impairments.

Neurodevelopmental disorders (NDDs) impose a global burden, affecting an increasing number of individuals. While some causative genes have been identified, understanding the human-specific mechanisms involved in these disorders remains limited. Traditional gene-driven approaches for modeling brain diseases have failed to capture the diverse and convergent mechanisms at play. Centrosomes and cilia act as intermediaries between environmental and intrinsic signals, regulating cellular behavior. Mutations or dosage variations disrupting their function have been linked to brain formation deficits, highlighting their importance, yet their precise contributions remain largely unknown. Hence, we aim to investigate whether the centrosome/cilia axis is crucial for brain development and serves as a hub for human-specific mechanisms disrupted in NDDs. Towards this direction, we first demonstrated species-specific and cell-type-specific differences in the cilia-genes expression during mouse and human corticogenesis. Then, to dissect their role, we provoked their ectopic overexpression or silencing in the developing mouse cortex or in human brain organoids. Our findings suggest that cilia genes manipulation alters both the numbers and the position of NPCs and neurons in the developing cortex. Interestingly, primary cilium morphology is disrupted, as we find changes in their length, orientation and number that lead to disruption of the apical belt and altered delamination profiles during development. Our results give insight into the role of primary cilia in human cortical development and address fundamental questions regarding the diversity and convergence of gene function in development and disease manifestation. It has the potential to uncover novel pharmacological targets, facilitate personalized medicine, and improve the lives of individuals affected by NDDs through targeted cilia-based therapies.

Caroline Williams-Gray is a Principal Research Associate in the Department of Clinical Neurosciences, University of Cambridge, and an honorary consultant neurologist specializing in Parkinson’s disease and movement disorders. She leads a translational research group investigating the clinical and biological heterogeneity of PD, with the ultimate goal of developing more targeted therapies for different Parkinson’s subtypes. Her recent work has focused on the theory that the immune system plays a significant role in mediating the heterogeneity of PD and its progression. Her lab is investigating this using blood and CSF -based immune markers, PET neuroimaging and neuropathology in stratified PD cohorts; and she is leading the first randomized controlled trial repurposing a peripheral immunosuppressive drug (azathioprine) to slow the progression of PD.

Maladaptive emotional memories contribute to the persistence of numerous mental health disorders, including post-traumatic stress disorder (PTSD), drug addiction and obsessive-compulsive disorder (OCD). Using rodent behavioural models of the psychological processes relevant to these disorders, it is possible to identify potential treatment targets for the development of new therapies, including those based upon disrupting the reconsolidation of maladaptive emotional memories. Using examples from rodent models relevant to multiple mental health disorders, this talk will consider some of the opportunities and challenges that this approach provides.

On Thursday, April 27th, we will host Hayriye Cagnan and Philip A. Starr. Hayriye Cagnan, PhD, is an associate professor at the MRC Brain Network Dynamics Unit and University of Oxford. She will tell us about “Therapies orchestrated by patients’ own rhythms”. Philip A. Starr, MD, PhD, is a neurosurgeon and professor of Neurological Surgery at the University of California San Francisco. Besides his scientific presentation on “My evolution in invasive human neurophysiology: from basal ganglia single units to chronic electrocorticography”, he will give us a glimpse at the person behind the science. The talks will be followed by a shared discussion. You can register via talks.stimulatingbrains.org to receive the (free) Zoom link!

Current disease-modifying therapies in multiple sclerosis are all focused on suppressing the inflammatory phase of the disease. This has been extremely successful, and it is doubtful that significantly more efficacious anti-inflammatory treatments will be found. However, it remains the case that people with relapsing-remitting multiple sclerosis acquire disability on treatment, and enter the secondary progressive phase. I argue that we now need treatments that prevent neuronal degeneration. The most promising approach is to prevent axons degenerating by remyelination. Since the discovery that the adult brain contains stem cells which can remyelinate, the problem now is how to promote endogenous remyelination, and how to know when we have achieved this! We have successfully identified one drug which promotes remyelination but unfortunately it is too toxic for use in the clinic. So the hunt continues.

Epilepsy is a common and disabling neurologic condition affecting adults and children that results from complex dysfunction of neural networks and is ineffectively treated with current therapies in up to one third of patients. This dysfunction can have especially severe consequences in pediatric age group, where neurodevelopment may be irreversibly affected. Furthermore, although seizures are the most obvious manifestation of epilepsy, the cognitive and psychiatric dysfunction that often coexists in patients with this disorder has the potential to be equally disabling.  Given these challenges, her research program aims to better understand how epileptic activity disrupts the proper development and function of neural networks, with the overall goal of identifying novel biomarkers and systems level treatments for epileptic disorders and their comorbidities, especially those affecting children.

Chronic exercise is a powerful intervention that lowers the incidence of most age-related diseases while promoting healthy metabolism in humans. However, illness, injury or age prevent many humans from consistently exercising. Thus, identification of molecular targets that can mimic the benefits of exercise would be a valuable tool to improve health outcomes of humans with neurodegenerative or mitochondrial diseases, or those with enforced sedentary lifestyles. Using a novel exercise platform for Drosophila, we have identified octopaminergic neurons as a key subset of neurons that are critical for the exercise response, and shown that periodic daily stimulation of these neurons can induce a systemic exercise response in sedentary flies. Octopamine is released into circulation where it signals through various octopamine receptors in target tissues and induces gene expression changes similar to exercise. In particular, we have identified several key molecules that respond to octopamine in skeletal muscle, including the mTOR modulator Sestrin, the PGC-1α homolog Spargel, and the FNDC5/Irisin homolog Iditarod. We are currently testing these molecules as potential therapies for multiple diseases that reduce mobility, including the PolyQ disease SCA2 and the mitochondrial disease Barth syndrome.

SCN8A encodes a major voltage-gated sodium channel expressed in CNS and PNS neurons.  Gain-of-function and loss-of-function mutations contribute to  human disorders, most notably Developmental and Epileptic Encephalophy (DEE). More than 600 affected individuals have been reported, with the most common  mechanism of de novo, gain-of-function mutations.  We have developed constitutive  and conditional models of gain- and loss- of function mutations in the mouse and  characterized the effects of on neuronal firing and neurological phenotypes.  Using CRE lines with cellular and developmental specificity, we have probed the effects of activating  mutant alleles in various classes of neurons in the developing and adult mouse.   Most recently, we are testing genetic therapies that reduce the expression  of gain-of-function mutant alleles.  We are comparing the effectiveness of allele specific  oligos (ASOs), viral delivery of shRNAs, and allele-specific targeting of mutant alleles  using Crispr/Cas9 in mouse models of DEE.

Brain aging leads to cognitive decline and is the main risk factor for sporadic forms of neurodegenerative diseases including Alzheimer’s disease. While brain cell- and tissue-intrinsic factors are likely key determinants of the aging process recent studies document a remarkable susceptibility of the brain to circulatory factors. Thus, blood borne factors from young mice or humans are sufficient to slow aspects of brain aging and improve cognitive function in old mice and, vice versa, factors from old mice are detrimental for young mice and impair cognition. We found evidence that the cerebrovasculature is an important target of circulatory factors and that brain endothelial cells show prominent age-related transcriptional changes in response to plasma. Furthermore, plasma proteins are taken up broadly into the young brain through receptor mediated transport which declines with aging. At the same time, brain derived proteins are detectable in plasma allowing us to measure physiological changes linked to brain aging in plasma. We are exploring the relevance of these findings for neurodegeneration and potential applications towards therapies.

The visual system of the brain is highly parallel in its architecture. This is clearly evident in the outputs of the retina, which arise from neurons called ganglion cells. Work in our lab has shown that mammalian retinas contain more than a dozen distinct types of ganglion cells. Each type appears to filter the retinal image in a unique way and to relay this processed signal to a specific set of targets in the brain. My students and I are working to understand the meaning of this parallel organization through electrophysiological and anatomical studies. We record from light-responsive ganglion cells in vitro using the whole-cell patch method. This allows us to correlate directly the visual response properties, intrinsic electrical behavior, synaptic pharmacology, dendritic morphology and axonal projections of single neurons. Other methods used in the lab include neuroanatomical tracing techniques, single-unit recording and immunohistochemistry. We seek to specify the total number of ganglion cell types, the distinguishing characteristics of each type, and the intraretinal mechanisms (structural, electrical, and synaptic) that shape their stimulus selectivities. Recent work in the lab has identified a bizarre new ganglion cell type that is also a photoreceptor, capable of responding to light even when it is synaptically uncoupled from conventional (rod and cone) photoreceptors. These ganglion cells appear to play a key role in resetting the biological clock. It is just this sort of link, between a specific cell type and a well-defined behavioral or perceptual function, that we seek to establish for the full range of ganglion cell types. My research concerns the structural and functional organization of retinal ganglion cells, the output cells of the retina whose axons make up the optic nerve. Ganglion cells exhibit great diversity both in their morphology and in their responses to light stimuli. On this basis, they are divisible into a large number of types (>15). Each ganglion-cell type appears to send its outputs to a specific set of central visual nuclei. This suggests that ganglion cell heterogeneity has evolved to provide each visual center in the brain with pre-processed representations of the visual scene tailored to its specific functional requirements. Though the outline of this story has been appreciated for some time, it has received little systematic exploration. My laboratory is addressing in parallel three sets of related questions: 1) How many types of ganglion cells are there in a typical mammalian retina and what are their structural and functional characteristics? 2) What combination of synaptic networks and intrinsic membrane properties are responsible for the characteristic light responses of individual types? 3) What do the functional specializations of individual classes contribute to perceptual function or to visually mediated behavior? To pursue these questions, we label retinal ganglion cells by retrograde transport from the brain; analyze in vitro their light responses, intrinsic membrane properties and synaptic pharmacology using the whole-cell patch clamp method; and reveal their morphology with intracellular dyes. Recently, we have discovered a novel ganglion cell in rat retina that is intrinsically photosensitive. These ganglion cells exhibit robust light responses even when all influences from classical photoreceptors (rods and cones) are blocked, either by applying pharmacological agents or by dissociating the ganglion cell from the retina. These photosensitive ganglion cells seem likely to serve as photoreceptors for the photic synchronization of circadian rhythms, the mechanism that allows us to overcome jet lag. They project to the circadian pacemaker of the brain, the suprachiasmatic nucleus of the hypothalamus. Their temporal kinetics, threshold, dynamic range, and spectral tuning all match known properties of the synchronization or "entrainment" mechanism. These photosensitive ganglion cells innervate various other brain targets, such as the midbrain pupillary control center, and apparently contribute to a host of behavioral responses to ambient lighting conditions. These findings help to explain why circadian and pupillary light responses persist in mammals, including humans, with profound disruption of rod and cone function. Ongoing experiments are designed to elucidate the phototransduction mechanism, including the identity of the photopigment and the nature of downstream signaling pathways. In other studies, we seek to provide a more detailed characterization of the photic responsiveness and both morphological and functional evidence concerning possible interactions with conventional rod- and cone-driven retinal circuits. These studies are of potential value in understanding and designing appropriate therapies for jet lag, the negative consequences of shift work, and seasonal affective disorder.

MicroRNAs are small noncoding RNAs that provide a critical layer of gene expression control. Individual microRNAs variably exert effects across networks of genes via sequence-specific binding to mRNAs, fine-tuning protein levels. This helps coordinate the timing and specification of cell fate transitions during brain development and maintains neural circuit function and plasticity by activity-dependent (re)shaping of synapses and the levels of neurotransmitter components. MicroRNA levels have been found to be altered in tissue from the epileptogenic zone resected from adults with drug-resistant focal epilepsy and this has driven efforts to explore their therapeutic potential, in particular using antisense oligonucleotide (ASOs) inhibitors termed antimirs. Here, we review the molecular mechanisms by which microRNAs control brain excitability and the latest progress towards a microRNA-based treatment for temporal lobe epilepsy. We also look at whether microRNA-based approaches could be used to treat genetic epilepsies, correcting individual genes or dysregulated pathways. Finally, we look at how cells have evolved to maximise the efficiency of the microRNA system via RNA editing, where single base changes is capable of altering the repertoire of genes under the control of a single microRNA. The findings improve our understanding of the molecular landscape of the epileptic brain and may lead to new therapies.

WEBINAR 1 Breaking the barrier: Using focused ultrasound for the development of targeted therapies for brain tumours presented by Dr Ekaterina (Caty) Salimova, Monash Biomedical Imaging Glioblastoma multiforme (GBM) - brain cancer - is aggressive and difficult to treat as systemic therapies are hindered by the blood-brain barrier (BBB). Focused ultrasound (FUS) - a non-invasive technique that can induce targeted temporary disruption of the BBB – is a promising tool to improve GBM treatments. In this webinar, Dr Ekaterina Salimova will discuss the MRI-guided FUS modality at MBI and her research to develop novel targeted therapies for brain tumours. Dr Ekaterina (Caty) Salimova is a Research Fellow in the Preclinical Team at Monash Biomedical Imaging. Her research interests include imaging cardiovascular disease and MRI-guided focused ultrasound for investigating new therapeutic targets in neuro-oncology. - WEBINAR 2 Disposition of the Kv1.3 inhibitory peptide HsTX1[R14A], a novel attenuator of neuroinflammation presented by Sanjeevini Babu Reddiar, Monash Institute of Pharmaceutical Sciences The voltage-gated potassium channel (Kv1.3) in microglia regulates membrane potential and pro-inflammatory functions, and non-selective blockade of Kv1.3 has shown anti-inflammatory and disease improvement in animal models of Alzheimer’s and Parkinson’s diseases. Therefore, specific inhibitors of pro-inflammatory microglial processes with CNS bioavailability are urgently needed, as disease-modifying treatments for neurodegenerative disorders are lacking. In this webinar, PhD candidate Ms Sanju Reddiar will discuss the synthesis and biodistribution of a Kv1.3-inhibitory peptide using a [64Cu]Cu-DOTA labelled conjugate. Sanjeevini Babu Reddiar is a PhD student at the Monash Institute of Pharmaceutical Sciences. She is working on a project identifying the factors governing the brain disposition and blood-brain barrier permeability of a Kv1.3-blocking peptide.

My research uses electrophysiological techniques to evaluate normal retinal function, dysfunction caused by blinding retinal diseases and the restoration of function using a variety of therapeutic strategies. We can use our understanding or normal retinal function and disease-related changes to construct optimal therapeutic strategies and evaluate how they ameliorate the effects of disease. Retinitis pigmentosa (RP) is a family of blinding eye diseases caused by photoreceptor degeneration. The absence of the cells that for this primary signal leads to blindness. My interest in RP involves the evaluation of therapies to restore vision: replacing degenerated photoreceptors either with: (1) new stem or other embryonic cells, manipulated to become photoreceptors or (2) prosthetics devices that replace the photoreceptor signal with an electronic signal to light. Glaucoma is caused by increased intraocular pressure and leads to ganglion cell death, which eliminates the link between the retinal output and central visual processing. We are parsing out of the effects of increased intraocular pressure and aging on ganglion cells. Congenital Stationary Night Blindness (CSNB) is a family of diseases in which signaling is eliminated between rod photoreceptors and their postsynaptic targets, rod bipolar cells. This deafferents the retinal circuit that is responsible for vision under dim lighting. My interest in CSNB involves understanding the basic interplay between excitation and inhibition in the retinal circuit and its normal development. Because of the targeted nature of this disease, we are hopeful that a gene therapy approach can be developed to restore night vision. My work utilizes rodent disease models whose mutations mimic those found in human patients. While molecular manipulation of rodents is a fairly common approach, we have recently developed a mutant NIH miniature swine model of a common form of autosomal dominant RP (Pro23His rhodopsin mutation) in collaboration with the National Swine Resource Research Center at University of Missouri. More genetically modified mini-swine models are in the pipeline to examine other retinal diseases.

Controlling biological processes using light has increased the accuracy and speed with which researchers can manipulate many biological processes. Optical control allows for an unprecedented ability to dissect function and holds the potential for enabling novel genetic therapies. However, optogenetic experiments require adequate light sources with spatial, temporal, or intensity control, often a bottleneck for researchers. Here we detail how to build a low-cost and versatile LED illumination system that is easily customizable for different available optogenetic tools. This system is configurable for manual or computer control with adjustable LED intensity. We provide an illustrated step-by-step guide for building the circuit, making it computer-controlled, and constructing the LEDs. To facilitate the assembly of this device, we also discuss some basic soldering techniques and explain the circuitry used to control the LEDs. Using our open-source user interface, users can automate precise timing and pulsing of light on a personal computer (PC) or an inexpensive tablet. This automation makes the system useful for experiments that use LEDs to control genes, signaling pathways, and other cellular activities that span large time scales. For this protocol, no prior expertise in electronics is required to build all the parts needed or to use the illumination system to perform optogenetic experiments.

Temporal lobe epilepsy (TLE) is a progressive disorder mediated by pathological changes in molecular cascades and neural circuit remodeling in the hippocampus resulting in increased susceptibility to spontaneous seizures and cognitive dysfunction. Targeting these cascades could prevent or reverse symptom progression and has the potential to provide viable disease-modifying treatments that could reduce the portion of TLE patients (>30%) not responsive to current medical therapies. Changes in GABA(A) receptor subunit expression have been implicated in the pathogenesis of TLE, and the Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) pathway has been shown to be a key regulator of these changes. The JAK/STAT pathway is known to be involved in inflammation and immunity, and to be critical for neuronal functions such as synaptic plasticity and synaptogenesis. Our laboratories have shown that a STAT3 inhibitor, WP1066, could greatly reduce the number of spontaneous recurrent seizures (SRS) in an animal model of pilocarpine-induced status epilepticus (SE). This suggests promise for JAK/STAT inhibitors as disease-modifying therapies, however, the potential adverse effects of systemic or global CNS pathway inhibition limits their use. Development of more targeted therapeutics will require a detailed understanding of JAK/STAT-induced epileptogenic responses in different cell types. To this end, we have developed a new transgenic line where dimer-dependent STAT3 signaling is functionally knocked out (fKO) by tamoxifen-induced Cre expression specifically in forebrain excitatory neurons (eNs) via the Calcium/Calmodulin Dependent Protein Kinase II alpha (CamK2a) promoter. Most recently, we have demonstrated that STAT3 KO in excitatory neurons (eNSTAT3fKO) markedly reduces the progression of epilepsy (SRS frequency) in the intrahippocampal kainate (IHKA) TLE model and protects mice from kainic acid (KA)-induced memory deficits as assessed by Contextual Fear Conditioning. Using data from bulk hippocampal tissue RNA-sequencing, we further discovered a transcriptomic signature for the IHKA model that contains a substantial number of genes, particularly in synaptic plasticity and inflammatory gene networks, that are down-regulated after KA-induced SE in wild-type but not eNSTAT3fKO mice. Finally, we will review data from other models of brain injury that lead to epilepsy, such as TBI, that implicate activation of the JAK/STAT pathway that may contribute to epilepsy development.

Reflex circuits in the nervous system integrate changes in the environment with physiology. Compact clusters of brain neuron cell bodies, termed nuclei, are essential for receiving sensory input and for transmitting motor outputs to the body. These nucelii are critical relay stations which process incoming information and convert these signals to outgoing action potentials which regulate immune system functions. Thus, reflex neural circuits maintain parameters of immunological physiology within a narrow range optimal for health. Advances in neuroscience and immunology using optogenetics, pharmacogenetics, and functional mapping offer a new understanding of the importance of neural circuitry underlying immunity, and offer direct paths to new therapies.

Traumatic brain injury (TBI), a leading cause of acquired epilepsy, results in primary cellular injury as well as secondary neurophysiological and inflammatory responses which contribute to epileptogenesis. I will present our recent studies identifying a role for neuro-immune interactions, specifically, the innate immune receptor Toll-like receptor 4 (TLR4), in enhancing network excitability and cell loss in hippocampal dentate gyrus early after concussive brain injury. I will describe results indicating that the transient post-traumatic increases in dentate neurogenesis which occurs during the same early post-injury period augments dentate network excitability and epileptogenesis. I will provide evidence for the beneficial effects of targeting TLR4 and neurogenesis early after brain injury in limiting epileptogenesis. We will discuss potential mechanisms for convergence of the post-traumatic neuro-immune and neurogenic changes and the implications for therapies to reduce neurological deficits and epilepsy after brain injury.

Cluster headache is a brain disorder dominated clinically by dreadful episodes of excruciating pain with a circadian pattern and most often focused in bouts with circannual periodicity. As we have understood its neurobiology new therapies, including those directed at calcitonin gene-related peptide, are helpful improve the lives of sufferers.

Time and again we are faced with the question at what point in the treatment of schizophrenia a depot formulation should be used. The data on the so-called LAIs (Long-Acting Injectables) has steadily increased in recent years. Today, we have very good evidence for the early use of depot therapies. However, the willingness and consent of the patient for this form of pharmacotherapy remains central to the successful use of LAIs. In his lecture, Prof. Correll will talk about the current evidence for the use of LAIs summarizing the latest studies.

Parkinson's disease (PD) is the second most common neurodegenerative disorder, affecting 1% of over 65's; there is currently no effective treatment. Dopaminergic neuronal loss is hallmark in PD and yet despite decades of intensive research there is still no known therapeutic which will completely halt the disorder. As a result, identification of interventive therapies to reverse or prevent PD are essential. Using genetically faithful models (induced pluripotent stem cells and knock-in mice) of familial late onset PD (LRRK2 G2019S and GBA N370S) we have contributed to the literature that neuronal dysfunction precedes degeneration. Specifically, using whole cell patch clamp electrophysiology, biochemical, behavioural and molecular biological techniques, we have begun to investigate the fundamental processes that make neurons specialised i.e., synaptic function and neurotransmission. We illustrate those alterations to spontaneous neurotransmitter release, neuronal firing, and short-term plasticity as well as Ca2+ and energy dyshomeostasis, are some of the earliest observable pathological dysfunctions and are likely precursors to late-stage degeneration. These pathologies represent targets which can be manipulated to address causation, rather than the symptoms of the PD, and represent a marker that, if measurable in patients, could form the basis of early PD detection and intervention.

Reprogramming somatic cells to a pluripotent state via the induced pluripotent stem cell (iPSC) method offers an increasingly utilized approach for neurological disease modeling with patient-derived cells. Several groups, including ours, have applied the iPSC approach to model severe genetic developmental and epileptic encephalopathies (DEEs) with patient-derived cells. Although most studies to date involve 2-D cultures of patient-derived neurons, brain organoids are increasingly being employed to explore genetic DEE mechanisms. We are applying this approach to understand PMSE (Polyhydramnios, Megalencephaly and Symptomatic Epilepsy) syndrome, Rett Syndrome (in collaboration with Ben Novitch at UCLA) and Protocadherin-19 Clustering Epilepsy (PCE). I will describe our findings of robust structural phenotypes in PMSE and PCE patient-derived brain organoid models, as well as functional abnormalities identified in fusion organoid models of Rett syndrome. In addition to showing epilepsy-relevant phenotypes, both 2D and brain organoid cultures offer platforms to identify novel therapies. We will also discuss challenges and recent advances in the brain organoid field, including a new single rosette brain organoid model that we have developed. The field is advancing rapidly and our findings suggest that brain organoid approaches offers great promise for modeling genetic neurodevelopmental epilepsies and identifying precision therapies.

Large scale genetic studies and associated functional investigations have tremendously augmented our knowledge about the mechanisms underlying epileptic seizures, and sometimes also accompanying developmental problems. Pharmacotherapy of the epilepsies is routinely guided by trial and error, since predictors for a response to specific antiepileptic drugs are largely missing. The recent advances in the field of genetic epilepsies now offer an increasing amount of either well fitting established or new re-purposing therapies for genetic epilepsy syndromes based on understanding of the pathophysiological principles. Examples are provided by variants in ion channel or transporter encoding genes which cause a broad spectrum of epilepsy syndromes of variable severity and onset, (1) the ketogenic diet for glucose transporter defects of the blood-brain barrier, (2) Na+ channel blockers (e.g. carbamazepine) for gain-of-function Na+ channel mutations and avoidance of those drugs for loss-of-function mutations, and (3) specific K+ channel blockers for mutations with a gain-of-function defect in respective K+ channels. I will focus in my talk on the latter two including the underlying mechanisms, their relation to clinical phenotypes and possible therapeutic implications. In conclusion, genetic and mechanistic studies offer promising tools to predict therapeutic effects in rare epilepsies.

The establishment of effective therapies for neurodegenerative and neuropsychiatric diseases is still challenging and one of the reasons is that especially for age-associated neurodegenerative diseases pathology accumulates long before there are any clinical signs of disease. Thus, patients are often only diagnosed at an already advanced state of molecular pathology, when causative therapies fail. Thus, there is an urgent need for molecular biomarkers that could detect individuals at risk for developing a CNS disease and stratify patients. I will address epigenetic processes such as histone-modifications and non-coding RNAs as potential approaches for patient stratification and therapeutic interaction, with a specific focus on RNA-therapies. Here, I plan to cover examples from our recent research on Alzheimer’s disease and Schizophrenia.

Dr. Gupta is carrying out his post doctoral studies in the Buter Laboratory in UCLA. He is applying his his knowledge of embryology to stem cells for developing regenerative therapies to treat spinal cord injuries. In this talk, he will discuss how understanding the logic for spinal cord development led us to derive diverse sensory neuronal classes from embryonic stem cells. The spinal sensory neurons enableus to perceive our environment through modalities that are lost in spinal injury patients. These ESC derived senory neurons can help regain sensation in spina cord injury patients through regenerative therapies.

Studying the pathophysiology of late stage Parkinson’s disease (PD) – after the patients have experienced severe neuronal loss – has helped develop various symptomatic treatments for PD (e.g., deep brain stimulation). However, it has been of limited use in developing neuroprotective disease-modifying therapies (DMTs), because DMTs require interventions at much earlier stages of PD when vulnerable neurons are still intact. Because PD patients exhibit various non-motor prodromal symptoms (ie, symptoms that predate diagnosis), understanding the pathophysiology underlying these symptom could lead to earlier diagnosis and intervention. In my talk, I will present a recently elucidated example of how PD pathologies alter the channel biophysics of intact vagal motoneurons (known to be selectively vulnerable in PD) to drive dysautonomia that is reminiscent of prodromal PD. I will discuss how elucidating the pathophysiology of prodromal symptoms can lead to earlier diagnosis through the development of physiological biomarkers for PD.

Alzheimer’s disease is the most common age-related neurodegenerative disorder. Familial forms of Alzheimer’s disease associated with the accumulation of a toxic form of amyloid-β (Aβ) peptides are linked to mitochondrial impairment. The coenzyme nicotinamide adenine dinucleotide (NAD+) is essential for both mitochondrial bioenergetics and nuclear DNA repair through NAD+-consuming poly (ADP-ribose) polymerases (PARPs). Here, we analysed the metabolomic changes in flies over-expressing Aβ and showed a decrease of metabolites associated with nicotinate and nicotinamide metabolism, which is critical for mitochondrial function in neurons. We show that increasing the bioavailability of NAD+ protects against Aβ toxicity. Pharmacological supplementation using NAM, a form of vitamin B that acts as a precursor for NAD+ or a genetic mutation of PARP rescues mitochondrial defects, protects neurons against degeneration and reduces behavioural impairments in a fly model of Alzheimer’s disease. Next, we looked at links between PARP polymorphisms and vitamin B intake in patients with Alzheimer’s disease. We show that polymorphisms in the human PARP1 gene or the intake of vitamin B, are associated with a decrease in the risk and severity of Alzheimer’s disease. We suggest that enhancing the availability of NAD+ by either vitamin B supplements or the inhibition of NAD+-dependent enzymes, such as PARPs are potential therapies for Alzheimer’s disease.

There are currently no approved therapies to slow down the accumulation of neurological disability that occurs independently of relapses in multiple sclerosis (MS). International agencies are engaging to expedite the development of novel strategies capable of modifying disease progression, abrogating persistent CNS inflammation, and support degenerating axons in people with progressive MS. Understanding why regeneration fails in the progressive MS brain and developing new regenerative approaches is a key priority for the Pluchino Lab. In particular, we aim to elucidate how the immune system, in particular its cells called myeloid cells, affects brain structure and function under normal healthy conditions and in disease. Our objective is to find how myeloid cells communicate with the central nervous system and affect tissue healing and functional recovery by stimulating mechanisms of brain plasticity mechanisms such as the generation of new nerve cells and the reduction of scar formation. Applying combination of state-of-the-art omic technologies, and molecular approaches to study murine and human disease models of inflammation and neurodegeneration, we aim to develop experimental molecular medicines, including those with stem cells and gene therapy vectors, which slow down the accumulation of irreversible disabilities and improve functional recovery after progressive multiple sclerosis, stroke and traumatic injuries. By understanding the mechanisms of intercellular (neuro-immune) signalling, diseases of the brain and spinal cord may be treated more effectively, and significant neuroprotection may be achieved with new tailored molecular therapeutics.

Dravet syndrome is a severe epileptic encephalopathy that begins during the first year of life and leads to severe cognitive and social interaction deficits. It is mostly caused by heterozygous loss-of-function mutations in the SCN1A gene, which encodes for the alpha-subunit of the voltage-gated sodium channel (Nav1.1) and is responsible mainly of GABAergic interneuron excitability. While different therapies based on the upregulation of the healthy allele of the gene are being developed, the dynamics of reversibility of the pathology are still unclear. In fact, whether and to which extent the pathology is reversible after symptom onset and if it is sufficient to ensure physiological levels of Scn1a during a specific critical period of time are open questions in the field and their answers are required for proper development of effective therapies. We generated a novel Scn1a conditional knock-in mouse model (Scn1aSTOP) in which the endogenous Scn1a gene is silenced by the insertion of a floxed STOP cassette in an intron of Scn1a gene; upon Cre recombinase expression, the STOP cassette is removed, and the mutant allele can be reconstituted as a functional Scn1a allele. In this model we can reactivate the expression of Scn1a exactly in the neuronal subtypes in which it is expressed and at its physiological level. Those aspects are crucial to obtain a final answer on the reversibility of DS after symptom onset. We exploited this model to demonstrate that global brain re-expression of the Scn1a gene when symptoms are already developed (P30) led to a complete rescue of both spontaneous and thermic inducible seizures and amelioration of behavioral abnormalities characteristic of this model. We also highlighted dramatic gene expression alterations associated with astrogliosis and inflammation that, accordingly, were rescued by Scn1a gene expression normalization at P30. Moreover, employing a conditional knock-out mouse model of DS we reported that ensuring physiological levels of Scn1a during the critical period of symptom appearance (until P30) is not sufficient to prevent the DS, conversely, mice start to die of SUDEP and develop spontaneous seizures. These results offer promising insights in the reversibility of DS and can help to accelerate therapeutic translation, providing important information on the timing for gene therapy delivery to Dravet patients.

Empathy plays a critical role in social interactions, and many species, including rodents, display evolutionarily conserved behavioral antecedents of empathy. In both humans and rodents, the anterior cingulate cortex (ACC) encodes information about the affective state of others. However, little is known about which downstream targets of the ACC contribute to empathy behaviors. We optimized a protocol for the social transfer of pain behavior in mice and compared the ACC-dependent neural circuitry responsible for this behavior with the neural circuitry required for the social transfer of two related states: analgesia and fear. We found that a 1-hour social interaction between a bystander mouse and a cagemate experiencing inflammatory pain led to congruent mechanical hyperalgesia in the bystander. This social transfer led to activation of neurons in the ACC and several downstream targets, including the nucleus accumbens (NAc), which was revealed by monosynaptic rabies virus tracing to be directly connected to the ACC. Bidirectional manipulation of activity in ACC-to-NAc inputs influenced the acquisition of socially transferred pain. Further, the social transfer of analgesia also depended upon ACC-NAc inputs. By contrast, the social transfer of fear instead required activity in ACC projections to the basolateral amygdala. This shows that mice rapidly adopt the sensory-affective state of a social partner, regardless of the valance of the information (pain, fear, or pain relief). We find that the ACC generates specific and appropriate empathic behavioral responses through distinct downstream targets. More sophisticated understanding of evolutionarily conserved brain mechanisms of empathy will also expedite the development of new therapies for the empathy-related deficits associated with a broad range of neuropsychiatric disorders.

There are no effective disease-modifying therapies for neurodegenerative diseases such as Alzheimer’s, Parkinson’s, amyotrophic lateral sclerosis or Huntington’s disease. Huntington’s disease (HD) is a devastating autosomal dominantly inherited neurodegenerative disease and the world’s most common genetic dementia. I will present an overview of important approaches in development for targeting mutant HTT DNA and RNA (Tabrizi et al Neuron 2019), the cause of HD pathogenesis, and the translational pathway from bench to clinic for a HTT targeting antisense oligonucleotide (Tabrizi et al New England Journal of Medicine 2019, Tabrizi, Science 2020) which is now in phase 3 studies. In my talk I will also review some of the genetic approaches in development for other CNS diseases. I will talk a bit about my journey as a clinician scientist and share some of my learnings for young scientists on how to survive a career in science.

One of the major challenges in developing therapeutics for the neurodegenerative disorders is the blood-brain barrier, limiting the availability of systemically administered therapies such as recombinant proteins or monoclonal antibodies from reaching the brain. Direct central nervous system (CNS) gene therapy using adeno-associated virus vectors expressing a therapeutic protein, monoclonal antibody or inhibiting RNA-coding sequences has two characteristics ideal for therapy of neurodegenerative disorders: circumventing the blood-brain barrier by directly expressing the therapy in the brain and the ability to provide persistent therapy with only a single administration. There are several critical parameters relevant to successful CNS gene therapy, including choice of vector, design of the gene to be expressed, delivery/route of administration, dose and anti-vector immune responses. The presentation will focus on these issues, the current status of clinical trials of gene therapy for neurodegeneration and specific challenges that will need to be overcome to ensure the success of these therapies.

Brain and neuronal network development depend on a complex sequence of events, which include neurogenesis, migration, differentiation, synaptogenesis, and synaptic pruning. Perturbations to any of these processes, for example associated with ion channel gene mutations (i.e., channelopathies), can underlie neurodevelopmental disorders such as neonatal and infantile epilepsies, strongly impair psychomotor development and cause persistent deficits in cognition, motor skills, or motor control. The therapeutic options available are very limited, and prophylactic therapies for patients at an increased risk of developing such epilepsies do not exist yet. By using genetic mouse models in which we controlled the activities of Kv7/M or HCN/h-channels during different developmental periods, we obtained offspring with distinct neurological phenotypes that could not simply be reversed by the re-introduction of the affected ion channel in juvenile or adult animals. The results indicate that channelopathy/mutation-specific treatments of neonatal and infantile epilepsies and their comorbidities need to be targeted to specific sensitive periods.

Molecular imaging using Positron Emission Tomography (PET) has become a major biomedical imaging technology. Its application towards characterisation of biochemical processes in disease could enable early detection and diagnosis, development of novel therapies and treatment evaluation. The technology is underpinned by the use of imaging probes radiolabelled with short-lived radioisotopes which can be specific and selective for biological targets in vivo e.g. markers for receptors, protein deposits, enzymes and metabolism. My talk will focus on the increasing development and application of PET imaging to clinical research in neurodegenerative diseases, for which it can be applied to delineate and understand the various pathological components of these disorders.

Recent human gene discovery efforts show that gain-of-function (GOF) variants in the KCNT1gene, which encodes a Na+-activated K+ channel subunit, cause severe epilepsies and other neurodevelopmental disorders. Although the impact of these variants on the biophysical properties of the channels is well characterized, the mechanisms that link channel dysfunction to cellular and network hyperexcitability and human disease are unknown. Furthermore, precision therapies that correct channel biophysics in non-neuronal cells have had limited success in treating human disease, highlighting the need for a deeper understanding of how these variants affect neurons and networks. To address this gap, we developed a new mouse model with a pathogenic human variant knocked into the mouse Kcnt1gene. I will discuss our findings on the in vivo phenotypes of this mouse, focusing on our characterization of epileptiform neural activity using electrophysiology and widefield Ca++imaging. I will also talk about our investigations at the synaptic, cellular, and circuit levels, including the main finding that cortical inhibitory neurons in this model show a reduction in intrinsic excitability and action potential generation. Finally, I will discuss future directions to better understand the mechanisms underlying the cell-type specific effects, as well as the link between the cellular and network level effects of KCNT1 GOF.

Africa is blessed with a rich diversity and abundance in rodent and avian populations. This natural endowment on the continent portends research opportunities to study unique anatomical profiles and investigate animal models that may confer better neural architecture to study neurodegenerative diseases, adult neurogenesis, stroke and stem cell therapies. To this end, African researchers are beginning to pay closer attention to some of her indigenous rodents and birds in an attempt to develop spontaneous laboratory models for homegrown neuroscience-based research. For this presentation, I will be showing studies in our lab, involving cellular neuroanatomy of two rodents, the African giant rat (AGR) and Greater cane rat (GCR), Eidolon Bats (EB) and also the Striped Owl (SO). Using histological stains (Cresyl violet and Rapid Golgi) and immunohistochemical biomarkers (GFAP, NeuN, CNPase, Iba-1, Collagen 2, Doublecortin, Ki67, Calbindin, etc), and Electron Microscopy, morphology and functional organizations of neuronal and glial populations of the AGR , GCR, EB and SO brains have been described, with our work ongoing. In addition, the developmental profiles of the prenatal GCR brains have been chronicled across its entire gestational period. Brains of embryos/foetuses were harvested for gross morphological descriptions and then processed using immunofluorescence biomarkers to determine the pattern, onset, duration and peak of neurogenesis (Pax6, Tbr1, Tbr2, NF, HuCD, MAP2) and the onset and peak of glial cell expressions and myelination in the prenatal GCR. The outcome of these research efforts has shown unique neuroanatomical expressions and networks amongst Africa’s rich biodiversity. It is hopeful that continuous effort in this regard will provide sufficient basic research data on neural developments and cellular neuroanatomy with subsequent translational consequences.