NanoString has started an ambitious project called the "Spatial Organ Atlas." The goal of this initiative is to map the architecture of tissues with spatially resolved whole transcriptomics. In this study, we used the GeoMx® Mouse Whole Transcriptome Atlas (WTA) to segment and profile different structures of the mouse brain at the cellular and molecular level. Spatial whole transcriptomic data was benchmarked to orthogonal platforms as an independent validation of the results.

In a follow-up study done in conjunction with our collaborators at Emory University in Ellen Hess’ lab, we performed deep spatial transcriptomic profiling using GeoMx Mouse WTA on subpopulations of spiny projection neurons (SPNs) in the mouse striatum. SPN subpopulations are generally divided into those that express D1 dopamine receptors and those that express D2 dopamine receptors. Recently, it was shown that these subpopulations are more complex than previously thought whereby gene expression in SPNs is, in part, mediated by their position within regional striatal subdivisions.

To analyze SPNs, 10um fresh frozen coronal sections from six C57/BL6 (WT) mice (n=3 female, n=3 male) were placed across two slides. D1 and D2 SPNs were identified using Drd1 and Adora2a RNAScope probes respectively in combination with Syto13 for visualization of all nuclei. Regions of interest (ROIs) were selected in dorsomedial, dorsolateral, and ventrolateral striatum to identify cell-type specific gene expression signatures in regions previously associated with unique functional roles within the striatum. GeoMx data was benchmarked against bulk and single-cell RNAseq from matched samples with high concordance across all metrics, and spatial analysis yielded novel insights into striatal organization of SPNs in WT mice. 

FOR RESEARCH USE ONLY. Not for use in diagnostic procedures.

Learning Objectives:

1. Explain the concept of the Spatial Organ Atlas and how the Whole Transcriptome Atlas works.

2. Describe the different structures and substructures of the mouse brain and how their gene expression differs spatially.

3. Summarize the transcriptional differences between D1 and D2 spiny projection neurons in the mouse brain and how their gene expression is regulated by position in the striatum.

There are currently no approved therapeutics to promote neural repair following central nervous system (CNS) damage. Groundbreaking studies in neurotrauma and disease found that a family of extracellular matrix (ECM) molecules known as chondroitin sulfate proteoglycans (CSPGs) are increased at sites of CNS damage and inhibit endogenous repair mechanisms. The inhibitory effects of CSPGs are mediated through protein tyrosine phosphatase sigma (PTPσ), a potent CSPG receptor. NervGen has developed a novel, first-in-class PTPσ modulator, known as NVG-291, for treatment of nervous system damage due to trauma or disease. NVG-291 is a systemically administered, blood-brain barrier penetrating peptide currently undergoing a Phase 1 trial in healthy volunteers to investigate safety, tolerability and pharmacokinetics.

NVG-291 modulates the cellular response and impact of CSPGs on neural repair, regeneration, remyelination, plasticity and other processes within the central and peripheral nervous systems. Following nervous system damage, CSPGs are upregulated within the forming scar around areas of damage, where they inhibit regeneration of injured axons. In non-damaged CNS tissue, CSPGs are a key component of the perineuronal net (PNN), an ECM structure surrounding synapses, where they help maintain synaptic connections by restricting axonal sprouting and plasticity. However, the presence of PNNs in an injured environment inhibits synaptic and axonal plasticity, which could otherwise facilitate recovery through the generation of novel circuits to compensate for injured or dysfunctional pathways. NVG-291 modulation of the CSPG receptor, PTPσ, promotes injured axons to regenerate through areas of damage, and non-injured axons away from damage to sprout and form novel circuits to compensate for the loss of, and promote the return of, function. NVG-291 has been shown to promote clinically relevant improvements in a variety of preclinical models including spinal cord injury, peripheral nerve injury, stroke, and multiple sclerosis. Our goal is to explore NVG-291’s potential as a therapeutic intervention to facilitate recovery from neurodegenerative diseases.

Learning Objectives:

1. Describe how PTPσ and CSPGs inhibit functional recovery following nervous system damage.

2. Discuss potential applications of NVG-291 to promote regeneration, plasticity, and remyelination following nerve damage.

3. Analyze the rationale for NVG-291 and/or PTPσ modulation as a therapeutic intervention in degenerative diseases

The ability of light sheet microscopy to interrogate organoids, whole brain, and systems in 3D enables the study of complex neurological pathways, vasculature and disease models in unique ways. We will discuss considerations in tissue clearing and staining as well as state of the art technology that provides automation, cutting-edge optics, and flexibility of samples from batch imaging all the way up to an entire cleared adult mouse. We will show examples of how this technology is used in several areas of research to study neurological disease and function.

Learning Objectives:

1. Discuss advantages of light sheet fluorescence microscopy.

2. Break down automated high resolution 3D light sheet technology.

3. List practical applications for 3D light sheet microscopy in neuroscience.

Patients with implanted neural devices offer researchers unique opportunities to study the basic workings of the human brain. This is made possible by patients undergoing epilepsy monitoring or the surgical implantation of a deep brain stimulation device, patients with chronic implants like RNS systems, and patients participating in brain-machine interface studies to develop new neurotechnology. Should we utilize these opportunities to answer scientific questions about the brain and what’s at stake when we do? What do patients understand and value about their participation in these studies, which offer no direct therapeutic benefits? This talk will provide an overview of the ethical issues in basic human neuroscience research with implanted devices and the unique contextual features that engender them. Special attention will be given to intraoperative studies and challenges for consent.

Learning Objectives:

1. Explain the fundamental ethical challenges of basic human neuroscience research with implanted devices

2. Evaluate current practices against two leading ethical principles: maintaining the integrity of clinical care and ensuring voluntariness of participation.

Neuropore Therapies is discovering and developing novel small molecule disease-modifying therapeutics to treat patients with neurodegenerative diseases, including Parkinson’s disease and Amyotrophic Lateral Sclerosis. Due to a lack of validated clinical biomarkers for most neurodegenerative diseases, our early translational biomarker development strategy is necessarily based on evaluations of multivariate and multimodal measures in in vivo and in vitro preclinical target engagement and efficacy models. In this context, I will present our utilization of the Luminex MAGPIX® platform in an early preclinical discovery and development program evaluating dual toll-like receptor 2 and 9 antagonists for the treatment of neurodegenerative diseases. Our Luminex-based multiplexed evaluations of cell-based screening systems and animal model or human derived samples is providing valuable information to guide program candidate molecule selection, target indication selection, and translational biomarker development.

Learning Objectives:

1. Identify some of the challenges of developing disease-modifying therapeutics for neurodegenerative diseases.

2. Explain what types of biomarkers are needed to overcome these challenges.

3. Discuss how Luminex platform based multiplexed evaluations are being used in preclinical studies to inform clinical development strategy for evaluating putative neurodegenerative disease-modifying therapeutics.

Reading is a rapid, distributed process that engages multiple components across the cortical surface. To understand the neural substrates and their dynamic interactions that allow us to identify and read written words, we performed direct intracranial recordings in large cohorts of humans. This allowed us to isolate a dynamic spatiotemporal map of visual word recognition across the entire language-dominant cortex. We used this to track the bottom-up and top-down flows of information related to behaviorally relevant factors that govern reading speed. By combining these recordings with direct cortical stimulation, inducing transient disruption of processing, we also gain causal links between the neural computations and behaviour. These results can help us better understand this uniquely human ability and move us closer to more targeted interventions for people with dyslexia and other reading disabilities.

Learning Objectives:

1. Identify brain areas essential for the ability to read.

2. Describe cognitive and behavioural factors that affect our ability to identify and read words.

3. Explain dual-route cognitive models of reading and the brain areas associated with each route.

Several age-related neurodegenerative disorders are characterized by the deposition of aberrantly folded proteins. The histopathological hallmark of synucleinopathies is the deposition of ɑ-synuclein (ɑSyn) protein in the central and peripheral nervous system and these pathological features are often associated with region-specific symptomatology. Symptoms in the urogenital organs, as well as urinary tract infections, are common in multiple system atrophy (MSA), also in the years preceding the MSA diagnosis. It is unknown how MSA is triggered and these observations in prodromal MSA led us to hypothesize that synucleinopathy could be triggered by bacterial infection of the genitourinary tract causing ɑ-synuclein (ɑSyn) to aggregate in peripheral nerves innervating these organs. We show that bacterial infection of the urinary bladder can cause synucleinopathy in mice and we propose a novel role of ɑSyn in the innate immune system response to bacteria. Urinary tract infection with uropathogenic E. coli results in the de novo aggregation of ɑSyn during neutrophil infiltration. During infection, ɑSyn is released extracellularly from neutrophils as part of their extracellular traps. Chronic urinary tract infections aggravate ɑSyn pathology in humanized ɑSyn mice. Injection of human MSA aggregates into the urinary bladder leads to motor deficits and propagates ɑSyn pathology to the central nervous system in humanized mice overexpressing ɑSyn. With this work we link bacterial infections with synucleinopathy and show that a host response to environmental triggers can result in ɑSyn pathology that bears semblance to MSA.

Learning Objectives:

1. Define synucleinopathies and describe the histopathological hallmarks of multiple system atrophy.

2. Explain triggers of synucleinopathy and how peripheral triggers might propagate to the central nervous system.

3. Identify strategies to stop the progression of synucleinopathy.

Alzheimer’s and Parkinson’s diseases (AD, PD) are the two most common neurodegenerative disorders. Despite their debilitating effects and increasing prevalence in our society, no cure is known. Both diseases are characterized by the presence of aggregates in the brain, which include alpha-synuclein, tau and amyloid beta proteins. These proteins normally have distinct functions in neurons, yet they share a common pathological mechanism involving aggregation into oligomers and fibrils that form plaques in the brain.  Alpha-synuclein, tau and amyloid beta aggregates are associated with neuronal cell death and seed additional plaques as disease progresses. A key goal in advancing AD/PD drug discovery is developing disease models that effectively mimic the pathology observed in vivo. We developed consistent, scalable production methods to generate active alpha-synuclein, tau and amyloid beta oligomers and fibrils in vitro. We demonstrate that recombinant alpha synuclein aggregates are toxic to primary cortical neuron cultures, are transferred between neurons, and induce Parkinson’s pSer129 pathology in mouse brains. Further, we show that recombinant tau aggregates induce Alzheimer’s pSer202/pThr205 pathology in mouse brains, and synthetic amyloid beta aggregates are toxic to primary rat cortical neurons.  These molecular tools demonstrate exciting utility for seeding pathology in AD/PD disease models and facilitating primary research and drug discovery.

Learning Objectives:

1. Define key proteins aggregates targeted by Alzheimer’s and Parkinson’s disease drug development efforts.

2. Explain how protein aggregates are utilized to develop novel Alzheimer’s and Parkinson’s disease models.

Behavior in complex environments requires decisions that flexibly combine stimulus representations with context, goals, and memory. Two key aspects of such cognitive flexibility are the retrieval of information from memory when needed, and the ability to selectively utilize relevant information depending on task demands. These aspects, it is believed, depend on the medial frontal cortex (MFC) and the medial temporal lobe (MTL), but it is unclear how these structures interact during memory retrieval. To study this, we simultaneously recorded single neurons in MFC and MTL while human subjects alternated between making memory and categorization-based decisions. In our population analysis, we compared the neural representations of choice, familiarity, and image category across tasks using cross-condition generalization performance. We found a striking difference between brain areas: In the MTL, representations of stimulus familiarity and stimulus category were task-demand independent, whereas in the MFC, representations of stimulus familiarity, stimulus category, and choices were all highly sensitive to task demands. Choice representations in the MFC were also task-specific but not effector specific. Lastly, choices requiring memory retrieval selectively engaged phase-locking between theta-frequency band oscillations in MTL and MFC neurons. This work reveals a mechanism for selectively engaging memory retrieval and shows that, unlike perceptual decision-making, memory-related information is only represented in the medial frontal cortex when choices require it.

Learning Objectives:

1. Demonstrate the importance of studying neural representations across multiple tasks.

2. Introduce cross-task decoding and multi-dimensional scaling as quantitative and qualitative (respectively) measures of generalization performance.

3. Demonstrate task-specific interareal communication between the medial temporal lobe and medial frontal cortex.

We are in critical need of targeted and individualized treatments for mental health disorders, which affect nearly 50% of Americans during our lifetimes. Brain stimulation treatments, including repetitive transcranial magnetic stimulation (rTMS), represent the front-line of innovative approaches to correct dysfunctional brain networks for patients suffering from mental illness. rTMS is FDA-approved for depression and obsessive- compulsive disorder (OCD) with clinical trials underway for post-traumatic stress disorder (PTSD) and substance use, among others. However, as currently administered, rTMS lacks a biomarker to individually optimize treatment and thus suffers from a poor clinical response rate (<50%). Without personalization of rTMS, we risk a one-size-fits-all treatment for all psychiatric disorders, not dissimilar to how antidepressants are administered. In this talk, I provide an overview of the noninvasive brain stimulation field and outline the steps needed to improve the precision and efficacy of our treatments. Specifically, I first discuss how intracranial brain recordings paired with invasive and noninvasive stimulation can help us tease out the underlying neural mechanisms of stimulation-induced neural plasticity. I think move to noninvasive approaches, where we combine TMS with EEG to 1) develop and refine a brain biomarker related to depression, 2) start to explore the relationship between this biomarker and the multidimensional nature of stimulation parameters, and finally 3) outline pathways towards real-time monitoring and closed-loop adaptive brain stimulation.

Learning Objectives:

1. Discuss the challenges associated with noninvasive closed-loop brain stimulation technologies.

2. Discuss how electrophysiology can help guide and personalize these approaches.

Neuroscience is experiencing an exciting era of integrating novel materials and tools to record neural activity made possible through significant advances in materials science, electrical engineering, and computer science. Certain technologies integrating these advances, such as Neuropixels, has exponentially moved forward our understanding of brain function in rodents and other model systems. However, even though current standards recording from human brain cells in vivo have provided incredible insight into how the human brain works in the past 30 years, the shift from lower spatial resolution (e.g. single channel, contact to contact spacing >150 µm) to higher spatial resolution technologies (contact to contact spacing <150 µm) in recording single cell activity has not been broadly adopted in the human recording studies. Reasons can include regulatory and safety concerns as well as questions of whether these advanced, high-resolution technologies can offer anything more than what has been working for many researchers and clinical teams for decades.  I will attempt to lay out a series of studies we performed at multiple institutes including MGH that may paint a picture of the type and kind of neural activity these new tools could provide even in the operating room setting ranging from basic science to clinically relevant studies. In addition, I will discuss some of the challenges we had in implementing, and translating, these technologies for use in humans as well as try to answer questions on what these tools can offer in advancing our understanding of human single neurons.

Learning Objectives:

1. Define the limitations and challenges in current clinical brain recording devices in characterizing human brain activity.

2. Identify various challenges in translating novel neural recording devices to recording from the human brain in the clinical domain.

3. Define the clinically and scientifically relevant advances in our knowledge of the brain afforded by bringing these technologies into the human brain recording domain.

While our lives unfold over time, weaving dynamic information into continuous experience, our memories are organized as discrete events. Detection of cognitive boundaries is critical for segmenting continuous experience and structuring episodic memories. However, how this process is implemented remains unclear. Supported by the BRAIN Initiative, we form a multi-institutional consortium (Cedars-Sinai/Caltech, Boston Children’s/Harvard, Johns Hopkin, U Toronto, U Colorado, and UC Santa Barbara) to reveal the underlying neural dynamics and capitalize on the unique opportunity of multi-regional recordings from human single neurons in drug-resistant epilepsy patients. 

In this talk, I will first provide a scientific overview that motivates our study of cognitive boundaries. I will introduce our experimental paradigm and technical approaches that can capture neural responses to cognitive boundaries at different levels and test their impacts on the encoding and retrieval of episodic memory. I will also share our findings from the behavioral, single neuron, neural population perspectives and their interconnections. We observed neurons that respond to abstract cognitive boundaries between different episodes. Boundary-induced neural state changes during encoding predicted subsequent recognition accuracy but impaired event order memory, mirroring a fundamental behavioral tradeoff between content and time memory. Furthermore, the neural state following boundaries is reinstated during both successful retrieval and false memories. Together, these findings reveal a neuronal substrate for detecting cognitive boundaries that transform experience into mnemonic episodes and structure mental time travel during memory retrieval.

Learning Objectives:

1.     Demonstrate the precious opportunities for human neuroscience under the clinical setup.

2.     Explain the neural mechanism for detecting cognitive boundaries and its impact on episodic memory.

Detection of neural signatures related to pathological behavioral states could enable adaptive deep brain stimulation (DBS), a potential strategy for improving efficacy of DBS for neurological and psychiatric disorders. This approach requires identifying neural biomarkers of relevant behavioral states, a task best performed in ecologically valid environments. Here, in human participants with obsessive-compulsive disorder (OCD) implanted with recording-capable DBS devices, we synchronized chronic ventral striatum local field potentials with relevant, disease-specific behaviors. We captured over 1,000 h of local field potentials in the clinic and at home during unstructured activity, as well as during DBS and exposure therapy. The wide range of symptom severity over which the data were captured allowed us to identify candidate neural biomarkers of OCD symptom intensity. This work demonstrates the feasibility and utility of capturing chronic intracranial electrophysiology during daily symptom fluctuations to enable neural biomarker identification, a prerequisite for future development of adaptive DBS for OCD and other psychiatric disorders.

Learning Objectives:

1. Discuss the background on why adaptive deep brain stimulation for OCD may help to improve its therapeutic efficacy. 

2. Explain the challenges of conducting and analyzing ecological electrophysiological recordings with individuals suffering from severe psychiatric illness.

We present intracranial recordings that tap into some elementary components of linguistic meaning, with implications for our understanding of sentence processing and the distribution of concepts across the cortex. First, we review the spatiotemporal dynamics of basic phrase processing, exploring cortical signatures of combining two simple words into a larger phrase. We find a unique response in posterior superior temporal sulcus to meaningful phrases, relative to pairs of words that have no meaning. Second, we review cortical responses to concrete (“chair”) and abstract (“time”) words, revealing how abstract words rely on inferior frontal language areas while concrete words yield greater activation across lateral and medial temporal cortices. Third, we explore cortical responses for a naming-to-definition task involving either coherent or incoherent sentences. We find greater broadband gamma activity in medial parietal cortex and inferior frontal sulcus for sentences that generate a coherent meaning. Overall, these three independent directions for exploring language reveal how the human brain processes some of the most crucial aspects of meaning necessary for worldly engagements: combining words; understanding concrete concepts; processing meaningful sentences."

Learning Objectives:

1. Identify aspects of human language that are essential for everyday interactions.

2. Isolate areas of cortex that these language functions appear to rely on.

3. Consider implications of these findings for therapeutic interventions in aphasia.

Major depression (MDD) is a common psychiatric condition and a leading cause of disability worldwide. While psychotherapy and pharmacotherapy are effective treatments for the majority of people, a substantial number of patients remain refractory to all available treatments.  Neuromodulation such as deep brain stimulation (DBS), is a promising solution for these people.  However, results from randomized controlled trials of DBS for depression have been inconsistent, suggesting novel strategies for neuromodulation are needed. One such strategy is personalized closed-loop neurostimulation.  It addresses the challenge posed by the etiological and diagnostic heterogeneity of depression.   Personalized closed-loop neurostimulation involves individualized target selection, customized biomarker driven stimulation, and continuous neural sensing so that treatment is both spatially and temporally individualized. In this talk, I will discuss efforts toward personalizing brain stimulation. I will then present interim findings from a safety and feasibility study of personalized closed-loop DBS at UCSF.

Learning Objectives:

1. State 3 approaches for personalized deep brain stimulation.

2. Identify 3 important properties of stimulation response.

3. Explain the concept of closed-loop control.

4. Explain how spectral and network features can be integrated to identify individual depression subnetworks.

Rates of mental health disorders have risen globally in the past two years. The term "mental health crisis" has been widely used and a sense of urgency has been present in health care institutions and for mental health professionals about how to address increased suffering and the subsequent need for more mental health services. Drawing upon current research in the field and my own clinical experience I will provide context to how symptoms of depression, anxiety, and ptsd are manifesting in individuals and communities. Further, I will discuss a socioecological approach to address resilience, recovery, and wellbeing from and individual, societal, and systemic perspective. 

Learning Objectives:

1. List current statistics on mental health disorders related to the COVID-19 pandemic.

2. Explain depression/anxiety/ptsd from a loss and grief framework.

3. Examine a socioecological perspective to recovery and wellbeing.

4. Apply a mindfulness activity to aid in restoring a sense of vitality.

Treatment-resistant depression is an immense source of disability and suffering, and represents a major unmet clinical need for innovative and effective therapies. Deep brain stimulation trials for treatment-resistant depression have evaluated a variety of targets, but have not yet led to clarity on the neural circuit modulation necessary for sustained treatment response. The current study represents a step toward greater mechanistic understanding of the pathophysiological state underlying treatment-resistant depression, as well as contributing new means of characterizing the system-wide response to direct intracranial stimulation modulating sub-components of the network. In this study, deep brain stimulation electrodes are implanted in two canonical targets (ventral capsule/ventral striatum and subcallosal cingulate), alongside temporarily-implanted stereotactic EEG electrodes across the frontotemporal networks of depression. Recordings from the network at rest, during depression-relevant tasks, and during targeted exploration of stimulation parameter space are then used to constrain our understanding of the disease state signature, with new implications for how best to modulate it to drive treatment response in and individualized fashion. 

Learning Objectives:

1. Describe the structure and purpose of Stereo-EEG as a diagnostic tool.

2. Describe a method of selecting stimulation parameters based on individual intracranial recordings.

3. Name one limitation of diffusion tensor imaging in defining affective networks for neuromodulation.

Brain wave synchronization, also called neuronal coherence, is a fundamental mechanism of communication in the brain, where synchronized field potentials coordinate synaptic and spiking events to support plasticity and learning. Although the spread of field potentials has garnered great interest, little is known about the spatial reach of neuronal coherence. Here we used simultaneous recordings from electrocorticography grids and high-density microelectrode arrays to estimate the spatial reach of neuronal coherence and spike-field coherence (SFC) across frontal, temporal, and occipital cortices during cognitive tasks in humans. We observed the strongest coherence within a 2-3 cm distance from the microelectrode arrays, potentially defining an effective range for local communication. This range was consistent across brain regions, frequencies, and cognitive tasks. The magnitude of coherence showed power law decay with increasing distance from the microelectrode arrays, where the highest coherence occurred between ECoG contacts, followed by coherence between ECoG and deep cortical LFP, and then SFC (ECoG > LFP > SFC). The spectral frequency of coherence also affected its magnitude. Alpha coherence was generally higher than other frequencies for signals nearest the microelectrode arrays, whereas delta coherence was higher for signals that were farther away. Action potentials in all brain regions were most coherent with the phase of alpha oscillations, which suggests that alpha waves could play a larger, more spatially local role in spike timing than other frequencies. These findings provide a deeper understanding of the spatial and spectral dynamics of neuronal coherence, further advancing knowledge about how activity propagates across the human brain.

Learning Objectives:

1.    Describe the underlying nature of brain waves.

2.    Explain the importance of brain wave synchronization to cognition and behavior.

3.    Identify factors that play a role in how synchronization spreads across the brain.