Neurology Commons^™

Shared Neural Geometries For Bilingual Semantic Representations In Human Hippocampal Neurons, Xinyuan Yan, Ana G Chavez, Melissa Franch, Kalman A Katlowitz, Ivy Gautam, Brian Kim, Aaditya Krishna, Aadit Shrivastava, Katie Van Arsdel, James Belanger, Assia Chericoni, Taha Ismail, Elizabeth A Mickiewicz, Danika Paulo, Hanlin Zhu, Alica M Goldman, Vaishnav Krishnan, Atul Maheshwari, Eleonora Bartoli, Nicole R Provenza, Seng Bum Michael Yoo, Benjamin Y Hayden, Sameer A Sheth

Duncan NRI Faculty and Staff Publications

The human brain has the remarkable ability to comprehend and express similar concepts in multiple languages. To understand how it does so, we examined responses of hippocampal neurons during passive listening, directed speaking, and spontaneous conversation in both English and Spanish in a small group of balanced bilinguals. We found a small number of putative "cross-language neurons," whose responses to equivalent words (e.g., "tierra" and "earth") are correlated. However, neurons' semantic tunings differed substantially by language, suggesting language-specific neural implementations. Instead, the crucial driver of translation was a preserved geometric organization of neural responses between the two languages, one that …

Neuropathological Hallmarks During The Chronic Phase Of Ischemic Stroke In Mice And Humans, Romeesa Khan, Gary Guzman, Trang Do, Patrick Devlin, John Ahn, Chunfeng Tan, Venugopal Reddy Venna, Sean P Marrelli, Haniyeh Koochak, Claudia M Di Gesù, Anthony Flores, Louise D Mccullough, Rodney M Ritzel

Faculty, Staff and Student Publications

Background: Advances in acute stroke care, including endovascular thrombectomy and improved neurocritical management, have increased survival after ischemic stroke. However, stroke remains a leading cause of long-term disability, with many survivors experiencing persistent neurological and cognitive impairments. The chronic neurological consequences of stroke, particularly its potential to accelerate brain aging, remain poorly understood.

Methods: We examined chronic neurobehavioral changes at 2 and 6 months after middle cerebral artery occlusion in male C57Bl/6 mice. Behavioral assessments included the open field test (OFT), novel object recognition test (NORT), fear conditioning (FC), nesting activity, and tail suspension testing. Transcriptomic profiling was performed using …

Cerebellar Oligodendrocytic Α-Synuclein Pathology And Dentate Nucleus Neuronal Hypertrophy In Parkinson’S Disease, Diego Iacono, Hui Peng, John Paul Bouffard, Roger Kurlan

Department of Neurology Faculty Papers

Idiopathic Parkinson's disease (iPD) research has historically prioritized basal ganglia dysfunction and neuronal Lewy body pathology, often overlooking cerebellar and non-neuronal cells contributions. This study investigates cerebellar neuropathology in iPD, specifically focusing on neuronal and non-neuronal cells of the dentate nucleus (DN) and its adjacent white matter (DN-WM). We systematically assessed autopsy-confirmed iPD brains vs. age-matched controls using immunohistochemistry and stereology-based morphometry methods. The study evaluated α-synuclein pathology, other common age-related co-occurring pathologies (β-amyloid, Tau, neuroinflammation), myelin integrity (Luxol-Fast-Blue), and neuronal volumetric changes in the DN of the cerebellum. In iPD brains, we identified intracytoplasmic α-synuclein inclusions within oligodendrocytes across …

Non-Synaptic Function And Localization Of Syntaxin-Binding Protein 1 In A Mouse Model Of Stxbp1-Related Epileptic Encephalopathy, Tao Yang, Rajat Banerjee, Yamei Deng, Sheetal Jahagirdar, Joo Hyun Kim, Wu Chen, Mingshan Xue, Alexey I Nesvizhskii, Michael D Uhler, Jack M Parent, Yu Wang

Duncan NRI Faculty and Staff Publications

Objective: De novo mutations in the syntaxin-binding protein 1 (STXBP1), encoded by STXBP1, are among the most prevalent causes of variable neurodevelopmental disorders, including epileptic encephalopathy, developmental delay, and movement disorders. Although STXBP1 has been proposed as a critical presynaptic protein controlling synaptic vesicle exocytosis, clinical phenotypes also suggest that its biological function could be more diverse.

Methods: The expression pattern of STXBP1 was studied using immunostaining in vitro and in vivo. Synaptosome isolation was performed to investigate the synaptic and non-synaptic localization of STXBP1 in the brain. STXBP1 immunoprecipitation followed by mass spectrometry (MS) was conducted to identify protein …

A Distinct Pp2a Subunit Regulates Local Protein Phosphorylation At The Axon Initial Segment, Andrew P Anderson, Sanghyun Kim, Allison J Melton, Xiaoyun Ding, Wei Zhang, Alexander B Saltzman, Anna Malovannaya, Matthew N Rasband, Yudong Gao

Faculty, Staff and Students Publications

Protein phosphorylation plays a crucial role in regulating the cytoskeletal and membrane proteins at the axon initial segment (AIS). However, our knowledge of AIS-specific kinases and phosphatases is very limited. Here, we report the identification of a protein phosphatase 2A (PP2A) B55 regulatory subunit enriched at the AIS in mice: Ppp2r2c. Our results demonstrate that PP2A-B55 subunits exhibit substantial heterogeneity in their subcellular localization and function. Notably, the Ppp2r2c subunit is selectively concentrated at the AIS, and this enrichment is driven by its unique structure. Utilizing a microelectrode array system (MEA), we show that Ppp2r2c modulates neuronal activity during in …

Ezhip Boosts Neuronal-Like Synaptic Gene Programs And Depresses Polyamine Metabolism, Elham Hasheminasabgorji, Huey-Miin Chen, Taylor A Gatesman, Subhi Talal Younes, Gabrielle A Nobles, Farhang Jaryani, Heather Mao, Kwanha Yu, Benjamin Deneen, Wee Yong, Michael D Taylor, Sameer Agnihotri, Marco Gallo

Faculty, Staff and Students Publications

It is currently understood that the characteristic loss of the repressive histone mark H3K27me3 in PFA ependymoma and diffuse midline glioma (DMG) are caused by complementary mechanisms mediated by EZHIP and the oncohistone H3K27M, respectively. To support the complementarity of these mechanisms, rare H3K27M-negative DMGs express EZHIP. Interestingly, EZHIP is one of the few genes recurrently mutated in PFA. The significance of EZHIP mutations in PFA, and whether EZHIP has wider functions in addition to repression of H3K27me3 deposition, are not known. Here, we investigated the mutational landscape of EZHIP in pediatric brain tumors. We found that EZHIP mutations occur …

Microglia Sensing Of Peripheral Signals That Bridge The Brain And Body, Claire E Young, Melanie A Samuel

Faculty, Staff and Students Publications

Microglia are the resident immune cell of the brain, and alterations in microglia signaling have been implicated in many neurodegenerative disorders. While microglia responses to central cues and other brain cell types are well documented, studies are increasingly investigating the impact of peripherally derived signals on microglia function. A diverse array of peripheral cues, including dietary components, hormones, and bacteria metabolites and components from the microbiome cross the blood brain barrier and directly influence microglia state through ligand-receptor interactions. This review highlights the complexity of brain-body interactions from the perspective of microglia function and proposes the idea that microglia could …

The Synaptic Architecture Of Layer 5 Thick Tufted Excitatory Neurons In Mouse Visual Cortex, Agnes L Bodor, Casey M Schneider-Mizell, Chi Zhang, Leila Elabbady, Alex Mallen, Andi Bergeson, Derrick Brittain, Joann Buchanan, Daniel J Bumbarger, Rachel Dalley, Clare Gamlin, Emily Joyce, Daniel Kapner, Sam Kinn, Gayathri Mahalingam, Sharmishtaa Seshamani, Shelby Suckow, Marc Takeno, Russel Torres, Wenjing Yin, J Alexander Bae, Manuel A Castro, Sven Dorkenwald, Akhilesh Halageri, Zhen Jia, Chris Jordan, Nico Kemnitz, Kisuk Lee, Kai Li, Ran Lu, Thomas Macrina, Eric Mitchell, Shanka Subhra Mondal, Shang Mu, Barak Nehoran, Sergiy Popovych, William Silversmith, Nicholas L Turner, Szi-Chieh Yu, William Wong, Jingpeng Wu, Brendan Celii, Luke Campagnola, Stephanie C Seeman, Tim Jarsky, Naixin Ren, Anton Arkhipov, Jacob Reimer, H Sebastian Seung, R Clay Reid, Forrest Collman, Nuno Maçarico Da Costa

Faculty, Staff and Students Publications

Despite significant progress in characterizing neocortical cell types, a complete understanding of the synaptic connections of individual excitatory cells remains elusive. This study investigates the connectivity of mouse visual cortex thick tufted layer 5 pyramidal cells, also known as extratelencephalic neurons (L5-ETns), using a 1 mm3 publicly available electron microscopy dataset. The analysis reveals that, in their immediate vicinity, L5-ETns primarily establish connections with a group of inhibitory cell types, which, in turn, specifically target the L5-ETns back. The most common excitatory targets of L5-ETns are layer 5 intertelencephalic neurons (L5-ITns) and layer 6 (L6) pyramidal cells, whereas synapses with …

Rapid Dissection And Dissociation Of The Mouse Olfactory Epithelium For Single-Nucleus Suspensions, Benjamin D W Belfort, Anthony M Insalaco, Claude C Chew, Johnathan D Jia, Julia Younis, Benjamin R Arenkiel

Duncan NRI Faculty and Staff Publications

The murine olfactory epithelium is the initial entry point of the olfactory system, housing various cell types that include olfactory sensory neurons, their regenerating progenitors, and support cells. Olfactory sensory neurons transduce chemical odorants into neural signals, yet the mechanisms underlying how these cells develop and turnover, create synapses with the olfactory bulb, and regulate their odorant receptors remain areas of intense study. Located on the dorsal aspect of the nasal cavity, the olfactory epithelium adheres to intricate bony structures known as turbinates. This anatomy poses unique challenges for its extraction and dissociation, especially in the context of preparing viable …

The Metastatic Role Of The Cxcl10-Cxcr3 Axis And Its Therapeutic Potential In Osteosarcoma, Benjamin B Gyau, Junyan Wang, Xiang Chen, Margaret A Clement, Zoe D Man, Angela M Major, Mathew C Weiser, Jun Xu, John Hicks, Tsz-Kwong Man

Faculty, Staff and Students Publications

The CXCL10-CXCR3 axis regulates immunity, tumorigenesis, and metastasis in multiple cancers. Yet, its roles in osteosarcoma (OS), the predominant pediatric malignant bone tumor, are not fully defined. Our prior work has shown that elevated serum CXCL10 levels correlate with poor OS prognosis. The current study delves deeper by investigating how CXCL10-mediated CXCR3 signaling influences OS growth and metastatic spread. In vitro, CXCL10 and related CXCR3 ligands (CXCL4, CXCL9, and CXCL11) enhanced OS tumor cell migration. In an orthotopic xenograft mouse model with a newly created CXCR3 knockout (KO) mutant, tumor growth and lung metastasis decreased significantly when compared with …

Alzheimer’S Disease Protective Allele Of Clusterin Modulates Neuronal Excitability Through Lipid-Droplet-Mediated Neuron-Glia Communication, Xiaojie Zhao, Yan Li, Siwei Zhang, Ari Sudwarts, Hanwen Zhang, Alena Kozlova, Matthew J Moulton, Lindsey D Goodman, Zhiping P Pang, Alan R Sanders, Hugo J Bellen, Gopal Thinakaran, Jubao Duan

Duncan NRI Faculty and Staff Publications

Background: Genome-wide association studies (GWAS) of Alzheimer's disease (AD) have identified a plethora of risk loci. However, the disease variants/genes and the underlying mechanisms have not been extensively studied.

Methods: Bulk ATAC-seq was performed in induced pluripotent stem cells (iPSCs) differentiated various brain cell types to identify allele-specific open chromatin (ASoC) SNPs. CRISPR-Cas9 editing generated isogenic pairs, which were then differentiated into glutamatergic neurons (iGlut). Transcriptomic analysis and functional studies of iGlut co-cultured with mouse astrocytes assessed neuronal excitability and lipid droplet formation.

Results: We identified a putative causal SNP of CLU that impacted neuronal chromatin accessibility to transcription-factor(s), with …

The Potential Of Brain Organoids In Addressing The Heterogeneity Of Synucleinopathies, Xiao-Jun Diao, Claudio Soto, Fei Wang, Yu Wang, Yun-Cheng Wu, Abhisek Mukherjee

Faculty, Staff and Student Publications

Synucleinopathies are a group of diseases characterized by neuronal and glial accumulation of α-synuclein (aSyn) linked with different clinical presentations, including Parkinson's disease (PD), Parkinson's disease with dementia (PDD), Dementia with Lewy Bodies (DLB) and Multiple system atrophy (MSA). Interestingly, the structure of the aSyn aggregates can vary across different synucleinopathies. Currently, it is unclear how the aSyn protein can aggregate into diverse structures and affect distinct cell types and various brain regions, leading to different clinical symptoms. Recent advances in induced pluripotent stem cells (iPSCs)-based brain organoids (BOs) technology provide an unprecedented opportunity to define the etiology of synucleinopathies …

An Unsupervised Map Of Excitatory Neuron Dendritic Morphology In The Mouse Visual Cortex, Marissa A Weis, Stelios Papadopoulos, Laura Hansel, Timo Lüddecke, Brendan Celii, Paul G Fahey, Eric Y Wang, J Alexander Bae, Agnes L Bodor, Derrick Brittain, Joann Buchanan, Daniel J Bumbarger, Manuel A Castro, Forrest Collman, Nuno Maçarico Da Costa, Sven Dorkenwald, Leila Elabbady, Akhilesh Halageri, Zhen Jia, Chris Jordan, Dan Kapner, Nico Kemnitz, Sam Kinn, Kisuk Lee, Kai Li, Ran Lu, Thomas Macrina, Gayathri Mahalingam, Eric Mitchell, Shanka Subhra Mondal, Shang Mu, Barak Nehoran, Sergiy Popovych, R Clay Reid, Casey M Schneider-Mizell, H Sebastian Seung, William Silversmith, Marc Takeno, Russel Torres, Nicholas L Turner, William Wong, Jingpeng Wu, Wenjing Yin, Szi-Chieh Yu, Jacob Reimer, Philipp Berens, Andreas S Tolias, Alexander S Ecker

Faculty, Staff and Students Publications

Neurons in the neocortex exhibit astonishing morphological diversity, which is critical for properly wiring neural circuits and giving neurons their functional properties. However, the organizational principles underlying this morphological diversity remain an open question. Here, we took a data-driven approach using graph-based machine learning methods to obtain a low-dimensional morphological "bar code" describing more than 30,000 excitatory neurons in mouse visual areas V1, AL, and RL that were reconstructed from the millimeter scale MICrONS serial-section electron microscopy volume. Contrary to previous classifications into discrete morphological types (m-types), our data-driven approach suggests that the morphological landscape of cortical excitatory neurons is …

Neurd Offers Automated Proofreading And Feature Extraction For Connectomics, Brendan Celii, Stelios Papadopoulos, Zhuokun Ding, Paul G Fahey, Eric Wang, Christos Papadopoulos, Alexander B Kunin, Saumil Patel, J Alexander Bae, Agnes L Bodor, Derrick Brittain, Joann Buchanan, Daniel J Bumbarger, Manuel A Castro, Erick Cobos, Sven Dorkenwald, Leila Elabbady, Akhilesh Halageri, Zhen Jia, Chris Jordan, Dan Kapner, Nico Kemnitz, Sam Kinn, Kisuk Lee, Kai Li, Ran Lu, Thomas Macrina, Gayathri Mahalingam, Eric Mitchell, Shanka Subhra Mondal, Shang Mu, Barak Nehoran, Sergiy Popovych, Casey M Schneider-Mizell, William Silversmith, Marc Takeno, Russel Torres, Nicholas L Turner, William Wong, Jingpeng Wu, Szi-Chieh Yu, Wenjing Yin, Daniel Xenes, Lindsey M Kitchell, Patricia K Rivlin, Victoria A Rose, Caitlyn A Bishop, Brock Wester, Emmanouil Froudarakis, Edgar Y Walker, Fabian Sinz, H Sebastian Seung, Forrest Collman, Nuno Maçarico Da Costa, R Clay Reid, Xaq Pitkow, Andreas S Tolias, Jacob Reimer

Faculty, Staff and Students Publications

We are in the era of millimetre-scale electron microscopy volumes collected at nanometre resolution1,2. Dense reconstruction of cellular compartments in these electron microscopy volumes has been enabled by recent advances in machine learning3–6. Automated segmentation methods produce exceptionally accurate reconstructions of cells, but post hoc proofreading is still required to generate large connectomes that are free of merge and split errors. The elaborate 3D meshes of neurons in these volumes contain detailed morphological information at multiple scales, from the diameter, shape and branching patterns of axons and dendrites, down to the fine-scale …

Foundation Model Of Neural Activity Predicts Response To New Stimulus Types, Eric Y Wang, Paul G Fahey, Zhuokun Ding, Stelios Papadopoulos, Kayla Ponder, Marissa A Weis, Andersen Chang, Taliah Muhammad, Saumil Patel, Zhiwei Ding, Dat Tran, Jiakun Fu, Casey M Schneider-Mizell, Microns Consortium, R Clay Reid, Forrest Collman, Nuno Maçarico Da Costa, Katrin Franke, Alexander S Ecker, Jacob Reimer, Xaq Pitkow, Fabian H Sinz, Andreas S Tolias

Faculty, Staff and Students Publications

The complexity of neural circuits makes it challenging to decipher the brain’s algorithms of intelligence. Recent breakthroughs in deep learning have produced models that accurately simulate brain activity, enhancing our understanding of the brain’s computational objectives and neural coding. However, it is difficult for such models to generalize beyond their training distribution, limiting their utility. The emergence of foundation models1 trained on vast datasets has introduced a new artificial intelligence paradigm with remarkable generalization capabilities. Here we collected large amounts of neural activity from visual cortices of multiple mice and trained a foundation model to accurately predict neuronal responses …

Functional Connectomics Reveals General Wiring Rule In Mouse Visual Cortex, Zhuokun Ding, Paul G Fahey, Stelios Papadopoulos, Eric Y Wang, Brendan Celii, Christos Papadopoulos, Andersen Chang, Alexander B Kunin, Dat Tran, Jiakun Fu, Zhiwei Ding, Saumil Patel, Lydia Ntanavara, Rachel Froebe, Kayla Ponder, Taliah Muhammad, J Alexander Bae, Agnes L Bodor, Derrick Brittain, Joann Buchanan, Daniel J Bumbarger, Manuel A Castro, Erick Cobos, Sven Dorkenwald, Leila Elabbady, Akhilesh Halageri, Zhen Jia, Chris Jordan, Dan Kapner, Nico Kemnitz, Sam Kinn, Kisuk Lee, Kai Li, Ran Lu, Thomas Macrina, Gayathri Mahalingam, Eric Mitchell, Shanka Subhra Mondal, Shang Mu, Barak Nehoran, Sergiy Popovych, Casey M Schneider-Mizell, William Silversmith, Marc Takeno, Russel Torres, Nicholas L Turner, William Wong, Jingpeng Wu, Wenjing Yin, Szi-Chieh Yu, Dimitri Yatsenko, Emmanouil Froudarakis, Fabian Sinz, Krešimir Josić, Robert Rosenbaum, H Sebastian Seung, Forrest Collman, Nuno Maçarico Da Costa, R Clay Reid, Edgar Y Walker, Xaq Pitkow, Jacob Reimer, Andreas S Tolias

Faculty, Staff and Students Publications

Understanding the relationship between circuit connectivity and function is crucial for uncovering how the brain computes. In mouse primary visual cortex, excitatory neurons with similar response properties are more likely to be synaptically connected1–8; however, broader connectivity rules remain unknown. Here we leverage the millimetre-scale MICrONS dataset to analyse synaptic connectivity and functional properties of neurons across cortical layers and areas. Our results reveal that neurons with similar response properties are preferentially connected within and across layers and areas—including feedback connections—supporting the universality of ‘like-to-like’ connectivity across the visual hierarchy. Using a validated digital twin model, …

Inhibitory Specificity From A Connectomic Census Of Mouse Visual Cortex, Casey M Schneider-Mizell, Agnes L Bodor, Derrick Brittain, Joann Buchanan, Daniel J Bumbarger, Leila Elabbady, Clare Gamlin, Daniel Kapner, Sam Kinn, Gayathri Mahalingam, Sharmishtaa Seshamani, Shelby Suckow, Marc Takeno, Russel Torres, Wenjing Yin, Sven Dorkenwald, J Alexander Bae, Manuel A Castro, Akhilesh Halageri, Zhen Jia, Chris Jordan, Nico Kemnitz, Kisuk Lee, Kai Li, Ran Lu, Thomas Macrina, Eric Mitchell, Shanka Subhra Mondal, Shang Mu, Barak Nehoran, Sergiy Popovych, William Silversmith, Nicholas L Turner, William Wong, Jingpeng Wu, Jacob Reimer, Andreas S Tolias, H Sebastian Seung, R Clay Reid, Forrest Collman, Nuno Maçarico Da Costa

Faculty, Staff and Students Publications

Mammalian cortex features a vast diversity of neuronal cell types, each with characteristic anatomical, molecular and functional properties1. Synaptic connectivity shapes how each cell type participates in the cortical circuit, but mapping connectivity rules at the resolution of distinct cell types remains difficult. Here we used millimetre-scale volumetric electron microscopy2 to investigate the connectivity of all inhibitory neurons across a densely segmented neuronal population of 1,352 cells spanning all layers of mouse visual cortex, producing a wiring diagram of inhibition with more than 70,000 synapses. Inspired by classical neuroanatomy, we classified inhibitory neurons based on targeting of …

Neuronal Network Activation Induced By Forniceal Deep Brain Stimulation In Mice, Bin Tang, Zhenyu Wu, Qi Wang, Jianrong Tang

Faculty, Staff and Students Publications

Background: The fimbria-fornix is a nerve fiber bundle that connects various structures of the limbic system in the brain and plays a key role in cognition. It has become a major target of deep brain stimulation (DBS) to treat memory impairment in both dementia patients and animal models of neurological diseases. Previously, we have reported the beneficial memory effects of chronic forniceal DBS in mouse models of intellectual disability disorders. In Rett syndrome and CDKL5 deficiency disorder models, DBS strengthens hippocampal synaptic plasticity, reduces dentate inhibitory transmission or increases adult hippocampal neurogenesis that aids memory. However, the underlying neuronal circuitry …

Foxr2 Targets Lhx6+/Dlx+ Neural Lineages To Drive Central Nervous System Neuroblastoma, Selin Jessa, Antonella De Cola, Bhavyaa Chandarana, Michael Mcnicholas, Steven Hébert, Adam Ptack, Damien Faury, Jessica W Tsai, Andrey Korshunov, Timothy N Phoenix, Benjamin Ellezam, David T W Jones, Michael D Taylor, Pratiti Bandopadhayay, Manav Pathania, Nada Jabado, Claudia L Kleinman

Faculty, Staff and Students Publications

Central nervous system neuroblastoma with forkhead box R2 (FOXR2) activation (NB-FOXR2) is a high-grade tumor of the brain hemispheres and a newly identified molecular entity. Tumors express dual neuronal and glial markers, leading to frequent misdiagnoses, and limited information exists on the role of FOXR2 in their genesis. To identify their cellular origins, we profiled the transcriptomes of NB-FOXR2 tumors at the bulk and single-cell levels and integrated these profiles with large single-cell references of the normal brain. NB-FOXR2 tumors mapped to LHX6+/DLX+ lineages derived from the medial ganglionic eminence, a progenitor domain in the ventral telencephalon. In vivo prenatal …

Molecular Logic For Cellular Specializations That Initiate The Auditory Parallel Processing Pathways, Junzhan Jing, Ming Hu, Tenzin Ngodup, Qianqian Ma, Shu-Ning Natalie Lau, M Cecilia Ljungberg, Matthew J Mcginley, Laurence O Trussell, Xiaolong Jiang

Faculty, Staff and Students Publications

The cochlear nuclear complex (CN), the starting point for all central auditory processing, encompasses a suite of neuronal cell types highly specialized for neural coding of acoustic signals. However, the molecular logic governing these specializations remains unknown. By combining single-nucleus RNA sequencing and Patch-seq analysis, we reveal a set of transcriptionally distinct cell populations encompassing all previously observed types and discover multiple hitherto unknown subtypes with anatomical and physiological identity. The resulting comprehensive cell-type taxonomy reconciles anatomical position, morphological, physiological, and molecular criteria, enabling the determination of the molecular basis of the specialized cellular phenotypes in the CN. In particular, …

Learning-Associated Astrocyte Ensembles Regulate Memory Recall, Michael R Williamson, Wookbong Kwon, Junsung Woo, Yeunjung Ko, Ehson Maleki, Kwanha Yu, Sanjana Murali, Debosmita Sardar, Benjamin Deneen

Faculty, Staff and Students Publications

The physical manifestations of memory formation and recall are fundamental questions that remain unresolved1. At the cellular level, ensembles of neurons called engrams are activated by learning events and control memory recall1-5. Astrocytes are in close proximity to neurons and engage in a range of activities that support neurotransmission and circuit plasticity6-10. Moreover, astrocytes exhibit experience-dependent plasticity11-13; however whether specific ensembles of astrocytes participate in memory recall remains obscure. Here we show that learning events induce c-Fos expression in a subset of hippocampal astrocytes, which subsequently …

Molecular Mechanism Governing The Plasticity Of Use-Dependent Spike Broadening In Dorsal Root Ganglion Neurons, Tyler D. Alexander, Stephen Tymanskyj, Kyle J. Kennedy, Leonard K. Kaczmarek, Manuel Covarrubias

SKMC Student Presentations and Publications

Use-dependent spike broadening (UDSB) results from inactivation of the voltage-gated K+ (Kv) channels that regulate the repolarization of the action potential. However, the specific signaling and molecular processes that modulate UDSB have remained elusive. Here, we applied an adeno-associated viral vector approach and dynamic clamping to conclusively demonstrate how multisite phosphorylation of the N-terminal inactivation domain (NTID) of the Kv3.4 channel modulates UDSB in rat dorsal root ganglion (DRG) neurons. The Kv3.4 phosphonull variant promotes slow recovery from inactivation, cumulative inactivation, and UDSB. In contrast, the Kv3.4 phosphomimic variant promotes fast recovery from inactivation and robust resistance to cumulative inactivation …

Identification Of An Early Subset Of Cerebellar Nuclei Neurons In Mice, Maryam Rahimi-Balaei, Shayan Amiri, Thomas Lamonerie, Sih-Rong Wu, Huda Y Zoghbi, G Giacomo Consalez, Daniel Goldowitz, Hassan Marzban

Duncan NRI Faculty and Staff Publications

Cerebellar nuclei (CN) neurons serve as the primary output of the cerebellum and originate from the cerebellar primordium at early stages of cerebellar development. These neurons are diverse, integrating information from the cerebellar cortex and relaying it to various brain regions. Employing various methodologies, we have characterized a specific subset of CN neurons that do not originate from the rhombic lip or ventricular zone of the cerebellar primordium. Embryos were collected at early stages of development and processed for immunohistochemistry (IHC), western blotting, in situ hybridization (ISH), embryonic culture, DiI labeling, and flow cytometry analysis (FCM). Our findings indicate that …

Mechanisms Of Memory-Supporting Neuronal Dynamics In Hippocampal Area Ca3, Yiding Li, John J Briguglio, Sandro Romani, Jeffrey C Magee

Faculty, Staff and Students Publications

Hippocampal CA3 is central to memory formation and retrieval. Although various network mechanisms have been proposed, direct evidence is lacking. Using intracellular Vm recordings and optogenetic manipulations in behaving mice, we found that CA3 place-field activity is produced by a symmetric form of behavioral timescale synaptic plasticity (BTSP) at recurrent synapses among CA3 pyramidal neurons but not at synapses from the dentate gyrus (DG). Additional manipulations revealed that excitatory input from the entorhinal cortex (EC) but not the DG was required to update place cell activity based on the animal’s movement. These data were captured by a computational model that …

Modeling Antisense Oligonucleotide Therapy In Mecp2 Duplication Syndrome Human Ipsc-Derived Neurons Reveals Gene Expression Programs Responsive To Mecp2 Levels, Sameer S Bajikar, Yehezkel Sztainberg, Alexander J Trostle, Harini P Tirumala, Ying-Wooi Wan, Caroline L Harrop, Jesse D Bengtsson, Claudia M B Carvalho, Davut Pehlivan, Bernhard Suter, Jeffrey L Neul, Zhandong Liu, Paymaan Jafar-Nejad, Frank Rigo, Huda Y Zoghbi

Faculty, Staff and Students Publications

Genomic copy-number variations (CNVs) that can cause neurodevelopmental disorders often encompass many genes, which complicates our understanding of how individual genes within a CNV contribute to pathology. MECP2 duplication syndrome (MDS or MRXSL in OMIM; OMIM#300260) is one such CNV disorder caused by duplications spanning methyl CpG-binding protein 2 (MECP2) and other genes on Xq28. Using an antisense oligonucleotide (ASO) to normalize MECP2 dosage is sufficient to rescue abnormal neurological phenotypes in mouse models overexpressing MECP2 alone, implicating the importance of increased MECP2 dosage within CNVs of Xq28. However, because MDS CNVs span MECP2 and additional genes, we generated human …

Alzheimer’S Disease Risk Gene Cd2ap Is A Dose-Sensitive Determinant Of Synaptic Structure And Plasticity, Matea Pavešković, Ruth B De-Paula, Shamsideen A Ojelade, Evelyne K Tantry, Mikhail Y Kochukov, Suyang Bao, Surabi Veeraragavan, Alexandra R Garza, Snigdha Srivastava, Si-Yuan Song, Masashi Fujita, Duc M Duong, David A Bennett, Philip L De Jager, Nicholas T Seyfried, Mary E Dickinson, Jason D Heaney, Benjamin R Arenkiel, Joshua M Shulman

Duncan NRI Faculty and Staff Publications

CD2-Associated protein (CD2AP) is a candidate susceptibility gene for Alzheimer's disease, but its role in the mammalian central nervous system remains largely unknown. We show that CD2AP protein is broadly expressed in the adult mouse brain, including within cortical and hippocampal neurons, where it is detected at pre-synaptic terminals. Deletion of Cd2ap altered dendritic branching and spine density, and impaired ubiquitin-proteasome system activity. Moreover, in mice harboring either one or two copies of a germline Cd2ap null allele, we noted increased paired-pulse facilitation at hippocampal Schaffer-collateral synapses, consistent with a haploinsufficient requirement for pre-synaptic release. Whereas conditional Cd2ap knockout in …

Identification Of An Ionic Mechanism For Erα-Mediated Rapid Excitation In Neurons, Meng Yu, Na Yin, Bing Feng, Peiyu Gao, Kaifan Yu, Hesong Liu, Hailan Liu, Yongxiang Li, Olivia Z Ginnard, Kristine M Conde, Mengjie Wang, Xing Fang, Longlong Tu, Jonathan C Bean, Qingzhuo Liu, Yue Deng, Yuxue Yang, Junying Han, Sanika V Jossy, Megan L Burt, Huey Zhong Wong, Yongjie Yang, Benjamin R Arenkiel, Yang He, Shaodong Guo, Pierre Gourdy, Jean-Francois Arnal, Francoise Lenfant, Zhao Wang, Chunmei Wang, Yanlin He, Yong Xu

Faculty, Staff and Students Publications

The major female ovarian hormone, 17β-estradiol (E2), can alter neuronal excitability within milliseconds to regulate a variety of physiological processes. Estrogen receptor-α (ERα), classically known as a nuclear receptor, exists as a membrane-bound receptor to mediate this rapid action of E2, but the ionic mechanisms remain unclear. Here, we show that a membrane channel protein, chloride intracellular channel protein-1 (Clic1), can physically interact with ERα with a preference to the membrane-bound ERα. Clic1-mediated currents can be enhanced by E2 and reduced by its depletion. In addition, Clic1 currents are required to mediate the E2-induced rapid excitations in multiple brain ERα …

Neuron-Glial Interactions: Implications For Plasticity, Behavior, And Cognition, Mauricio Rangel-Gomez, Cristina M Alberini, Benjamin Deneen, Gabrielle T Drummond, Tiina Manninen, Mriganka Sur, Aleksandra Vicentic

Faculty, Staff and Students Publications

The traditional view of glial cells as mere supportive tissue has shifted, due to advances in technology and theoretical conceptualization, to include a diversity of other functions, such as regulation of complex behaviors. Astrocytes, the most abundant glial cells in the central nervous system (CNS), have been shown to modulate synaptic functions through gliotransmitter-mediated neurotransmitter reuptake, influencing neuronal signaling and behavioral functions. Contemporary studies further highlight astrocytes' involvement in complex cognitive functions. For instance, inhibiting astrocytes in the hippocampus can lead to memory deficits, suggesting their integral role in memory processes. Moreover, astrocytic calcium activity and astrocyte-neuron metabolic coupling have …

Tau Is Required For Glial Lipid Droplet Formation And Resistance To Neuronal Oxidative Stress, Lindsey D Goodman, Isha Ralhan, Xin Li, Shenzhao Lu, Matthew J Moulton, Ye-Jin Park, Pinghan Zhao, Oguz Kanca, Ziyaneh S Ghaderpour Taleghani, Julie Jacquemyn, Joshua M Shulman, Kanae Ando, Kai Sun, Maria S Ioannou, Hugo J Bellen

Duncan NRI Faculty and Staff Publications

The accumulation of reactive oxygen species (ROS) is a common feature of tauopathies, defined by Tau accumulations in neurons and glia. High ROS in neurons causes lipid production and the export of toxic peroxidated lipids (LPOs). Glia uptake these LPOs and incorporate them into lipid droplets (LDs) for storage and catabolism. We found that overexpressing Tau in glia disrupts LDs in flies and rat neuron-astrocyte co-cultures, sensitizing the glia to toxic, neuronal LPOs. Using a new fly tau loss-of-function allele and RNA-mediated interference, we found that endogenous Tau is required for glial LD formation and protection against neuronal LPOs. Similarly, …

Distinct Basal Forebrain-Originated Neural Circuits Promote Homoeostatic Feeding And Suppress Hedonic Feeding In Male Mice, Hailan Liu, Jonathan C Bean, Yongxiang Li, Meng Yu, Olivia Z Ginnard, Kristine M Conde, Mengjie Wang, Xing Fang, Hesong Liu, Longlong Tu, Na Yin, Junying Han, Yongjie Yang, Qingchun Tong, Benjamin R Arenkiel, Chunmei Wang, Yang He, Yong Xu

Faculty, Staff and Students Publications

Feeding behaviour is influenced by two primary factors: homoeostatic needs driven by hunger and hedonic desires for pleasure even in the absence of hunger. While efficient homoeostatic feeding is vital for survival, excessive hedonic feeding can lead to adverse consequences such as obesity and metabolic dysregulations. However, the neurobiological mechanisms that orchestrate homoeostatic versus hedonic food consumption remain largely unknown. Here we show that GABAergic proenkephalin (Penk) neurons in the diagonal band of Broca (DBB) of male mice respond to food presentation. We further demonstrate that a subset of DBBPenk neurons that project to the paraventricular nucleus of the hypothalamus …