Neurosciences Commons^™

Platelets Cause Microvascular Occlusion And Delayed Neurological Deficits After Subarachnoid Hemorrhage In Mice., Ari Dienel, Sung-Ha Hong, Kiara Torres, Kanako Matsumura, Jose Guzman, Peeyush Thankamani Pandit, Bibek Samal, Harveen Kaur, Samitha Nemirajaiah, Angelica Bernal, H Alex Choi, Louise D Mccullough, Spiros L Blackburn, Jaroslaw Aronowski, Devin W Mcbride

Faculty, Staff and Student Publications

After subarachnoid hemorrhage (SAH), some patients develop delayed neurological deficits (DND). Microthrombi are considered a contributing factor to DND, but clinical trials of antiplatelets had mixed results. Existing research suggests that platelets play a role in the etiology of DND, but no comprehensive study has tested causality between platelets and DND after SAH. Here we hypothesize that after SAH, platelet activation promotes microthrombi formation, occlusion of the brain microvasculature and contributes to DND, and that inhibiting platelet aggregation is a therapeutic strategy. Mice experiencing SAH were administered various interventions. The animals were subjected to stimulation of platelets, platelet depletion, or …

Functional Bipartite Invariance In Mouse Primary Visual Cortex Receptive Fields, Zhiwei Ding, Dat Tran, Kayla Ponder, Zhuokun Ding, Rachel Froebe, Lydia Ntanavara, Paul G Fahey, Erick Cobos, Luca Baroni, Maria Diamantaki, Eric Y Wang, Andersen Chang, Stelios Papadopoulos, Jiakun Fu, Taliah Muhammad, Christos Papadopoulos, Santiago A Cadena, Alexandros Evangelou, Konstantin Willeke, Fabio Anselmi, Sophia Sanborn, Jan Antolik, Emmanouil Froudarakis, Saumil Patel, Edgar Y Walker, Jacob Reimer, Fabian H Sinz, Alexander S Ecker, Katrin Franke, Xaq Pitkow, Andreas S Tolias

Faculty, Staff and Students Publications

Sensory systems support generalization by representing features that persist under input variation; however, identifying the neuronal basis of these invariances remains difficult due to high-dimensional and nonlinear neural computations. Here we leverage the inception loop paradigm, iterating between large-scale recordings, predictive models and in silico experiments with in vivo verification, to characterize neuronal invariances in mouse primary visual cortex (V1). We synthesize varied exciting inputs (VEIs), dissimilar images that drive target neurons. These VEIs revealed a new bipartite invariance: one subfield encodes a shift-tolerant high-frequency texture and the other encodes a fixed low-frequency pattern. This division aligns with object boundaries …

Protein-Protein Interaction–Interfering Peptide Rescues Dysregulated Nmda Receptor Signaling, Robert E. Featherstone, Hongbin Li, Ameet S. Sengar, Karin E. Borgmann-Winter, Olya Melnychenko, Lindsey M. Crown, Ray L. Gifford, Felix Amirfathi, Anamika Banerjee, Aivi Tran, Krishna Parekh, Margaret Heller, Wenyu Zhang, Robert J. Gallop, Adam D. Marc, Pragya Komal, Michael W. Salter, Steven J. Siegel, Chang-Gyu Hahn

Farber Institute for Neuroscience Faculty Papers

The complex and heterogeneous genetic architecture of neuropsychiatric illnesses compels us to look beyond individual risk genes for therapeutic strategies and target the interactive dynamics and convergence of their protein products. A mechanistic substrate for convergence of synaptic neuropsychiatric risk genes are protein-protein interactions (PPIs) in the N-methyl-D-aspartate receptor (NMDAR) complex. NMDAR hypofunction in schizophrenia is associated with hypoactivity of Src kinase, resulting from convergent alterations in PPIs of Src with its partners. Of these, the association of Src with PSD-95, which inhibits the activity of this kinase in the NMDAR complex, is known to be increased in schizophrenia. Here, …

Restoration Of Sfrp3 Preserves The Neural Stem Cell Pool And Spatial Discrimination Ability In A Mouse Model Of Alzheimer's Disease, Chia-Hsuan Fu, Jin Park, Umberto Tosi, Francisco A Blanco, Manuel Silva-Pérez, Kavitha Muralidharan, Jason C You, Minjung Lee, Gabriel S Stephens, Xiaohong Zhang, Yi Zheng, Helen Scharfman, Kimberley F Tolias, Jeannie Chin

Faculty, Staff and Students Publications

Individuals with Alzheimer's disease (AD) have an increased incidence of seizures, which worsen cognitive decline. Using a transgenic mouse model of AD neuropathology that exhibits spontaneous seizures, we previously found that seizure activity stimulates and accelerates depletion of the hippocampal neural stem cell (NSC) pool, which was associated with deficits in neurogenesis-dependent spatial discrimination. However, the precise molecular mechanisms that drive seizure-induced activation and depletion of NSCs are unclear. Here, using mice of both sexes, we performed RNA-sequencing on the hippocampal dentate gyrus and identified differentially expressed regulators of neurogenesis in the Wnt signaling pathway that regulates many aspects of …

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 …

Pkr-Driven Isr Signaling Controls Synaptic Translation And Structural Plasticity In An Age-Dependent Manner, Nicolás W Martínez, Felipe Gómez, Ariel Tapia-Godoy, Juan Francisco Roa, Fernanda Moreso-Contreras, Yuwei Liu, Claudia Jara, Cheril Tapia-Rojas, Iván Alfaro, Mauro Costa-Mattioli, Soledad Matus

Faculty, Staff and Students Publications

The integrated stress response (ISR) modulates protein homeostasis in response to both intracellular and extracellular signals. The four kinases involved in the ISR all phosphorylate the same target, the alpha subunit of eukaryotic initiation factor 2 (eIF2α), to integrate various stress signals, thereby regulating cell fate. The activation of the ISR reprograms the proteome by inhibiting general protein synthesis while increasing the translation of specific mRNAs. In the brain, the ISR regulates the type of synaptic plasticity necessary for forming long-term memory. More importantly, the activation of the ISR has emerged as a causal mechanism underlying cognitive decline associated with …

Folliculin Depletion Results In Liver Cell Damage And Cholangiocarcinoma Through Mit/Tfe Activation, Bruno Maria Custode, Francesco Annunziata, Felipe Dos Santos Matos, Valentina Schiano, Veronica Maffia, Milena Lillo, Rita Colonna, Rossella De Cegli, Andrea Ballabio, Nunzia Pastore

Duncan NRI Faculty and Staff Publications

Mutations in the tumor suppressor gene Folliculin (FLCN) are responsible for Birt-Hogg-Dube’ (BHD) syndrome, a rare inherited condition that predisposes affected individuals to skin tumors, pulmonary cysts, and kidney tumors. FLCN regulates key cellular pathways, including TFEB, TFE3, and mTORC1, which are critical for maintaining cell homeostasis. Loss of FLCN leads to both hyperactivation of mTORC1 and constitutive activation of TFEB and TFE3, contributing to tumorigenesis. While previous studies showed that Flcn liver-specific conditional knockout (FlcnLiKO) mice are protected from developing liver fibrosis and damage upon high-fat diet exposure, the potential role of FLCN loss in liver carcinogenesis …

Templating Of Monomeric Alpha-Synuclein Results In Inflammation And Snpc Dopamine Neuron Death In A Genetic Mouse Model Of Induced Synucleinopathy, Matthew D. Byrne, Peyman Petramfar, Jae-Kyung Lee, Richard J. Smeyne

Department of Neuroscience Faculty Papers

While the etiology of most cases of Parkinson's disease (PD) are idiopathic, it has been estimated that 5-10% of PD arise from known genetic mutations. The first mutations described that leads to the development of an autosomal dominant form of PD are in the SNCA gene that codes for the protein alpha-synuclein (α-syn). α-syn is an abundant presynaptic protein that is natively disordered and whose function is still unclear. In PD, α-syn misfolds into multimeric b-pleated sheets that aggregate in neurons (Lewy Bodies/neurites) and spread throughout the neuraxis in a pattern that aligns with disease progression. Here, using IHC, HC, …

Formation Of An Expanding Memory Representation In The Hippocampus, Sachin P Vaidya, Guanchun Li, Raymond A Chitwood, Yiding Li, Jeffrey C Magee

Faculty, Staff and Students Publications

How brain networks connected by labile synapses store new information without catastrophically overwriting previous memories remains poorly understood. To examine this, we tracked the same population of hippocampal CA1 place cells (PCs) as mice learned a task for 7 days. We found evidence of memory formation as both the number of PCs maintaining a stable place field and the stability of individual PCs progressively increased across the week until most of the representation was composed of long-term stable PCs. The stable PCs disproportionately represented task-related learned information, were retrieved earlier within a behavioral session and showed a strong correlation with …

The Small Gtpase Rap1 In Pomc Neurons Regulates Leptin Actions And Glucose Metabolism, Kentaro Kaneko, Weisheng Lu, Yong Xu, Alexei Morozov, Makoto Fukuda

Faculty, Staff and Students Publications

The hypothalamic leptin-proopiomelanocortin (POMC) pathway is critical for regulating metabolism. POMC neurons in the arcuate nucleus respond to leptin and play a pivotal role in mediating energy and glucose balance. However, during diet-induced obesity (DIO), these neurons often develop resistance to exogenous leptin. Recently, the small GTPase Rap1 has been implicated as an inhibitor of neuronal leptin signaling; however, its specific role within POMC neurons remains unexplored. We generated tamoxifen-inducible, POMC neuron-specific Rap1 knockout mice to selectively delete both Rap1a and Rap1b isoforms in POMC neurons. By analyzing these mice through metabolic phenotyping, immunohistochemistry, and biochemical assays, we show that …

A Deep Learning Strategy To Identify Cell Types Across Species From High-Density Extracellular Recordings, Maxime Beau, David J Herzfeld, Francisco Naveros, Marie E Hemelt, Federico D'Agostino, Marlies Oostland, Alvaro Sánchez-López, Young Yoon Chung, Michael Maibach, Stephen Kyranakis, Hannah N Stabb, M Gabriela Martínez Lopera, Agoston Lajko, Marie Zedler, Shogo Ohmae, Nathan J Hall, Beverley A Clark, Dana Cohen, Stephen G Lisberger, Dimitar Kostadinov, Court Hull, Michael Häusser, Javier F Medina

Faculty, Staff and Students Publications

High-density probes allow electrophysiological recordings from many neurons simultaneously across entire brain circuits but fail to reveal cell type. Here, we develop a strategy to identify cell types from extracellular recordings in awake animals and reveal the computational roles of neurons with distinct functional, molecular, and anatomical properties. We combine optogenetics and pharmacology using the cerebellum as a testbed to generate a curated ground-truth library of electrophysiological properties for Purkinje cells, molecular layer interneurons, Golgi cells, and mossy fibers. We train a semi-supervised deep learning classifier that predicts cell types with greater than 95% accuracy based on the waveform, discharge …

Nitrate Ameliorates Alcohol-Induced Cognitive Impairment Via Oral Microbiota, Xiangxue Li, Zhaojun Ni, Weixiong Shi, Kangqing Zhao, Yanjie Zhang, Lina Liu, Zhong Wang, Jie Chen, Zhoulong Yu, Xuejiao Gao, Ying Qin, Jingwen Zhao, Wenjuan Peng, Jie Shi, Thomas R Kosten, Lin Lu, Lei Su, Yanxue Xue, Hongqiang Sun

Faculty, Staff and Students Publications

Alcohol use is associated with cognitive impairment and dysregulated inflammation. Oral nitrate may benefit cognitive impairment in aging through altering the oral microbiota. Similarly, the beneficial effects of nitrate on alcohol-induced cognitive decline and the roles of the oral microbiota merit investigation. Here we found that nitrate supplementation effectively mitigated cognitive impairment induced by chronic alcohol exposure in mice, reducing both systemic and neuroinflammation. Furthermore, nitrate restored the dysbiosis of the oral microbiota caused by alcohol consumption. Notably, removing the oral microbiota led to a subsequent loss of the beneficial effects of nitrate. Oral microbiota from donor alcohol use disordered …

Somatodendritic Orientation Determines Tdcs-Induced Neuromodulation Of Purkinje Cell Activity In Awake Mice, Carlos A Sánchez-León, Guillermo Sánchez-Garrido Campos, Marta Fernández, Álvaro Sánchez-López, Javier F Medina, Javier Márquez-Ruiz

Faculty, Staff and Students Publications

Transcranial direct-current stimulation (tDCS) of the cerebellum is a promising non-invasive neuromodulatory technique being proposed for the treatment of neurological and neuropsychiatric disorders. However, there is a lack of knowledge about how externally applied currents affect neuronal spiking activity in cerebellar circuits in vivo. We investigated how Cb-tDCS affects the firing rate of Purkinje cells (PC) and non-PC in the mouse cerebellar cortex to understand the underlying mechanisms behind the polarity-dependent modulation of neuronal activity induced by tDCS. Mice (n=9) were prepared for the chronic recording of local field potentials (LFPs) to assess the actual electric field gradient imposed by …

The Medial Olivocochlear Efferent Pathway Potentiates Cochlear Amplification In Response To Hearing Loss, Patricia M Quiñones, Michelle Pei, Hemant Srivastava, Ariadna Cobo-Cuan, Marcela A Morán, Bong Jik Kim, Clayton B Walker, Michael J Serafino, Frank Macias-Escriva, Juemei Wang, James B Dewey, Brian E Applegate, Matthew J Mcginley, John S Oghalai

Faculty, Staff and Students Publications

The mammalian cochlea receives efferent feedback from the brain. Many functions for this feedback have been hypothesized, including on short timescales, such as mediating attentional states, and long timescales, such as buffering acoustic trauma. Testing these hypotheses has been impeded by an inability to make direct measurements of efferent effects in awake animals. Here, we assessed the role of the medial olivocochlear (MOC) efferent nerve fibers on cochlear amplification by measuring organ of Corti vibratory responses to sound in both sexes of awake and anesthetized mice. We studied long-term effects by genetically ablating the efferents and/or afferents. Cochlear amplification increased …

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 …

Foraging Animals Use Dynamic Bayesian Updating To Model Meta-Uncertainty In Environment Representations, James Webb, Paul Steffan, Benjamin Y Hayden, Daeyeol Lee, Caleb Kemere, Matthew Mcginley

Faculty, Staff and Students Publications

Foraging theory predicts animal behavior in many contexts. In patch-based foraging behaviors, the marginal value theorem (MVT) gives the optimal strategy for deterministic environments whose parameters are fully known to the forager. In natural settings, environmental parameters exhibit variability and are only partially known to the animal based on its experience, creating uncertainty. Models of uncertainty in foraging are well established. However, natural environments also exhibit unpredicted changes in their statistics. As a result, animals must ascertain whether the currently observed quality of the environment is consistent with their internal models, or whether something has changed, creating meta-uncertainty. Behavioral strategies …

Alpha-Synuclein Phosphomimetic Y39e And S129d Knock-In Mice Show Cytosolic Alpha-Synuclein Localization Without Developing Neurodegeneration Or Motor Deficits, Youngdoo Kim, Bhupesh Vaidya, Joseph Mcinnes, Huda Y Zoghbi

Duncan NRI Faculty and Staff Publications

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by motor and nonmotor symptoms. Its pathological hallmarks include the accumulation of misfolded alpha-synuclein (α-Syn) in Lewy bodies and Lewy neurites. Phosphorylation of α-Syn is a prominent feature of these inclusions, but its role in disease pathogenesis remains unclear. To identify the role of α-Syn phosphorylation in synucleinopathy, we generated two Snca knock-in (KI) mouse models carrying phosphomimetic mutations at SncaY39 or SncaS129 (Snca^Y39E or Snca^S129D) which manipulated epitopes phosphorylated in the PD brain. Both Snca^Y39E and Snca^S129D KI mice displayed increased α-Syn phosphorylation, enhanced …

Distinct Patterns Of Pv And Sst Gabaergic Neuronal Activity In The Basal Forebrain During Olfactory-Guided Behavior In Mice, Elizabeth H Moss, Evelyne K Tantry, Elaine Le, Pey-Shyuan Chin, Priscilla Ambrosi, Katie L Brandel-Ankrapp, Benjamin R Arenkiel

Duncan NRI Faculty and Staff Publications

Sensory perception relies on the flexible detection and interpretation of stimuli across variable contexts, conditions, and behavioral states. The basal forebrain (BF) is a hub for behavioral state regulation, supplying dense cholinergic and GABAergic projections to various brain regions involved in sensory processing. Of GABAergic neurons in the BF, parvalbumin (PV) and somatostatin (SST) subtypes serve opposing roles toward regulating behavioral states. To elucidate the role of BF circuits in sensory-guided behavior, we investigated GABAergic signaling dynamics during odor-guided decision-making in male and female mice. We used fiber photometry to record cell type-specific BF activity during an odor discrimination task …

Altered Thermal Preference By Preoptic Estrogen Receptor Alpha Neurons In Postpartum Females, Nan Zhang, Meng Yu, Qianru Zhao, Bing Feng, Yue Deng, Jonathan C Bean, Qingzhuo Liu, Benjamin P Eappen, Yang He, Kristine M Conde, Hailan Liu, Yongjie Yang, Longlong Tu, Mengjie Wang, Yongxiang Li, Na Yin, Hesong Liu, Junying Han, Darah Ave Threat, Nathan Xu, Taylor Smiley, Pingwen Xu, Lulu Chen, Tianshu Zeng, Yanlin He, Chunmei Wang

Faculty, Staff and Students Publications

OBJECTIVE: This study aims to investigate how reproductive experience (RE) alters thermal preference and thermoregulation in female mice, with a focus on estrogen receptor alpha (ERα)-expressing neurons in the preoptic area (POA).

METHODS: Thermal preference and body temperature were measured in female mice with and without RE, and virgin female mice with selective deletion of ERα from the POA (ERα

RESULTS: We showed that female mice prefer a cooler environment starting from late pregnancy and persisting long term postpartum. Female mice with RE (>4 weeks post-weaning) displayed lower body temperature and a lower thermal preferred temperature, and lost preference …

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 …

Targeting Tiam1 Enhances Hippocampal-Dependent Learning And Memory In The Adult Brain And Promotes Nmda Receptor-Mediated Synaptic Plasticity And Function, Francisco A Blanco, Md Ali Bin Saifullah, Jinxuan X Cheng, Carlota Abella, Federico Scala, Karen Firozi, Sanyong Niu, Jin Park, Jeannie Chin, Kimberley F Tolias

Faculty, Staff and Students Publications

Excitatory synapses and the actin-rich dendritic spines on which they reside are indispensable for information processing and storage in the brain. In the adult hippocampus, excitatory synapses must balance plasticity and stability to support learning and memory. However, the mechanisms governing this balance remain poorly understood. Tiam1 is an actin cytoskeleton regulator prominently expressed in the dentate gyrus (DG) throughout life. Previously, we showed that Tiam1 promotes dentate granule cell synapse and spine stabilization during development, but its role in the adult hippocampus remains unclear. Here, we deleted Tiam1 from adult forebrain excitatory neurons (Tiam1^fKO) and assessed …

Sex-Specific Astrocyte Regulation Of Spinal Motor Circuits By Nkx61, Navish A Bosquez Huerta, Zhung-Fu Lee, Eun-Ah Christine Song, Junsung Woo, Yi-Ting Cheng, Debosmita Sardar, Ozlem Sert, Ehson Maleki, Kwanha Yu, Ekin Su Akdemir, Kaitlyn Sanchez, Juyeon Jo, Matthew N Rasband, Hyun Kyoung Lee, Akdes Serin Harmanci, Benjamin Deneen

Faculty, Staff and Students Publications

Astrocytes exhibit diverse cellular and molecular properties across the central nervous system (CNS). Recent studies identified region-specific transcription factors (TF) that oversee these diverse properties; how sex differences intersect with region-specific transcriptional programs to regulate astrocyte function is unknown. Here, we show that the TF Nkx6.1 is specifically expressed in ventral astrocytes of the spinal cord and that its deletion results in sex-specific effects on astrocyte morphology. Astrocytes from males exhibit enhanced morphological complexity, accompanied by increased motor function and cholinergic synapses. In contrast, female astrocytes exhibit reduced complexity and no changes in motor function. Mechanistically, we found that Nkx6.1 …

Sex Differences In Response To Diet Enriched With Glutathione Precursors In The Aging Heart, Aude Angelini, Grecia Garcia Marquez, Anna Malovannaya, Marta L Fiorotto, Alexander Saltzman, Antrix Jain, Joann Trial, George E Taffet, Katarzyna A Cieslik

Faculty, Staff and Students Publications

Common features of the aging heart are dysregulated metabolism, inflammation, and fibrosis. Elevated oxidative stress is another hallmark of cardiac aging that can exacerbate each of these conditions. We hypothesize that by increasing natural antioxidant levels (glutathione), we will improve cardiac function. Twenty-one-month-old mice were fed glycine and N-acetyl cysteine (GlyNAC; glutathione precursors)-supplemented or control diets for 12 weeks. Heart function was monitored longitudinally, and the exercise performance was determined at the end of the study. We found that the GlyNAC diet was beneficial for old male but not old female mice, leading to an increase of Ndufb8 expression (a …

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 …

Chronic Β3-Ar Stimulation Activates Distinct Thermogenic Mechanisms In Brown And White Adipose Tissue And Improves Systemic Metabolism In Aged Mice, Duraipandy Natarajan, Bhuvana Plakkot, Kritika Tiwari, Shoba Ekambaram, Weidong Wang, Michael Rudolph, Mahmoud A Mohammad, Shaji K Chacko, Madhan Subramanian, Stefano Tarantini, Andriy Yabluchanskiy, Zoltan Ungvari, Anna Csiszar, Priya Balasubramanian

Faculty, Staff and Students Publications

Adipose thermogenesis has been actively investigated as a therapeutic target for improving metabolic dysfunction in obesity. However, its applicability to middle-aged and older populations, which bear the highest obesity prevalence in the United States (approximately 40%), remains uncertain due to age-related decline in thermogenic responses. In this study, we investigated the effects of chronic thermogenic stimulation using the β3-adrenergic (AR) agonist CL316,243 (CL) on systemic metabolism and adipose function in aged (18-month-old) C57BL/6JN mice. Sustained β3-AR treatment resulted in reduced fat mass, increased energy expenditure, increased fatty acid oxidation and mitochondrial activity in adipose depots, improved glucose homeostasis, and a …

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 …

Neuroprotective Effect Of L-Dopa-Induced Interleukin-13 On Striatonigral Degeneration In Cerebral Ischemia, Eunhae Jeon, Myeong-Seong Seo, Enkhmaa Lkhagva-Yondon, Yu-Ree Lim, Seung-Woo Kim, Yu Jeong Kang, Jun Seok Lee, Byoung Dae Lee, Rayul Wi, So-Yoon Won, Young Cheul Chung, Eun S Park, Eunhee Kim, Byung Kwan Jin, Myung-Shin Jeon

Faculty, Staff and Student Publications

Levodopa (L-DOPA) treatment is a clinically effective strategy for improving motor function in patients with ischemic stroke. However, the mechanisms by which modulating the dopamine system relieves the pathology of the ischemic brain remain unclear. Emerging evidence from an experimental mouse model of ischemic stroke, established by middle cerebral artery occlusion (MCAO), suggested that L-DOPA has the potential to modulate the inflammatory and immune response that occurs during a stroke. Here, we aimed to demonstrate the therapeutic effect of L-DOPA in regulating the systemic immune response and improving functional deficits in mice with ischemia. Transient MCAO led to progressive degeneration …

Nerve Injury Inhibits Oprd1 And Cnr1 Transcription Through Rest In Primary Sensory Neurons, Ashok Subedi, Asieh Etemad, Aadhya Tiwari, Yuying Huang, Biji Chatterjee, Samantha M Mcleod, Yungang Lu, Diangelo Gonzalez, Krishna Ghosh, Mario Sirito, Sanjay K Singh, Elisa Ruiz, Sandra L Grimm, Cristian Coarfa, Hui-Lin Pan, Sadhan Majumder

Faculty, Staff and Students Publications

The transcription repressor REST in the dorsal root ganglion (DRG) is upregulated by peripheral nerve injury and promotes the development of chronic pain. However, the genes targeted by REST in neuropathic pain development remain unclear. The expression levels of four opioid receptor genes (Oprm1, Oprd1, Oprl1 and Oprk1) and the cannabinoid CB1 receptor (Cnr1) gene in the DRG regulate nociception. In this study, we determined the role of REST in controlling their expression in the DRG induced by spared nerve injury (SNI). SNI induced chronic pain hypersensitivity in wild-type mice and was accompanied by increased levels of Rest transcript and …

Vagus Nerve Stimulation Recruits The Central Cholinergic System To Enhance Perceptual Learning, Kathleen A Martin, Eleni S Papadoyannis, Jennifer K Schiavo, Saba Shokat Fadaei, Habon A Issa, Soomin C Song, Sofia Orrey Valencia, Nesibe Z Temiz, Matthew J Mcginley, David A Mccormick, Robert C Froemke

Duncan NRI Faculty and Staff Publications

Perception can be refined by experience, up to certain limits. It is unclear whether perceptual limits are absolute or could be partially overcome via enhanced neuromodulation and/or plasticity. Recent studies suggest that peripheral nerve stimulation, specifically vagus nerve stimulation (VNS), can alter neural activity and augment experience-dependent plasticity, although little is known about central mechanisms recruited by VNS. Here we developed an auditory discrimination task for mice implanted with a VNS electrode. VNS applied during behavior gradually improved discrimination abilities beyond the level achieved by training alone. Two-photon imaging revealed VNS induced changes to auditory cortical responses and activated cortically …

Neuregulin1 Nuclear Signaling Influences Adult Neurogenesis And Regulates A Schizophrenia Susceptibility Gene Network Within The Mouse Dentate Gyrus, Prithviraj Rajebhosale, Alice Jone, Kory R Johnson, Rohan Hofland, Camille Palarpalar, Samara Khan, Lorna W Role, David A Talmage

Faculty, Staff and Student Publications

Neuregulin1 (Nrg1) signaling is critical for neuronal development and function from fate specification to synaptic plasticity. Type III Nrg1 is a synaptic protein which engages in bidirectional signaling with its receptor ErbB4. Forward signaling engages ErbB4 phosphorylation, whereas back signaling engages two known mechanisms: (1) local axonal PI3K-AKT signaling and (2) cleavage by γ-secretase resulting in cytosolic release of the intracellular domain (ICD), which can traffic to the nucleus (Bao et al., 2003; Hancock et al., 2008). To dissect the contribution of these alternate signaling strategies to neuronal development, we generated a transgenic mouse with a missense mutation (V