Medical Neurobiology Commons^™

Pediatric Neurotropic Infection Alters Synaptic Development In The Developing Brain, Anuoluwapo Grace Fadare, Yashika S. Kamte, Manish N. Chandwani, Lauren A. O'Donnell

Rowan-Virtua Research Day

Many neurotropic viruses cause more significant pathology in younger hosts as their brains are still developing. This experiment asked how central nervous system (CNS) viral-infections affect the development of synapses in the pediatric brain during infection and post-infection. Synaptogenesis is at its peak in pediatric mice (10 days old) and we hypothesized that a neurotropic infection could disrupt synaptic proteins. We used a transgenic mouse model where measles virus (MV) infects only mature neurons, leading us to question whether synapses were impacted. We examined synaptic markers in the cerebellum and hippocampus in MV-infected and uninfected mice 9 days and 90 …

A Novel Spatiotemporal Graph Convolutional Network Framework For Functional Connectivity Biomarkers Identification Of Alzheimer’S Disease, Ying Zhang, Le Xue, Shuoyan Zhang, Jiacheng Yang, Qi Zhang, Min Wang, Luyao Wang, Mingkai Zhang, Jiehui Jiang, Yunxia Li

Faculty, Staff and Student Publications

BACKGROUND: Functional connectivity (FC) biomarkers play a crucial role in the early diagnosis and mechanistic study of Alzheimer's disease (AD). However, the identification of effective FC biomarkers remains challenging. In this study, we introduce a novel approach, the spatiotemporal graph convolutional network (ST-GCN) combined with the gradient-based class activation mapping (Grad-CAM) model (STGC-GCAM), to effectively identify FC biomarkers for AD.

METHODS: This multi-center cross-racial retrospective study involved 2,272 participants, including 1,105 cognitively normal (CN) subjects, 790 mild cognitive impairment (MCI) individuals, and 377 AD patients. All participants underwent functional magnetic resonance imaging (fMRI) and T1-weighted MRI scans. In this study, …

Synaptic Vesicle Dynamics In Mouse Rod Bipolar Cells, Sara S Patterson, Rebecca J Girresch, Marcus A Mazzaferri, Andrea S Bordt, Wendy L Piñon-Teal, Brett D Jesse, Dinukie-Chantal W Perera, Melanie A Schlepphorst, James A Kuchenbecker, Alice Z Chuang, Jay Neitz, David W Marshak, Judith Mosinger Ogilvie

Faculty, Staff and Student Publications

Considerable progress has been made in studying the receptive fields of the most common primate retinal ganglion cell (RGC) types, such as parasol RGCs. Much less is known about the rarer primate RGC types and the circuitry that gives rise to noncanonical receptive field structures. The goal of this study was to analyze synaptic inputs to smooth monostratified RGCs to determine the origins of their complex spatial receptive fields, which contain isolated regions of high sensitivity called "hotspots." Interestingly, smooth monostratified RGCs co-stratify with the well-studied parasol RGCs and are thus constrained to receiving input from bipolar and amacrine cells …

Regulation Of Syntaxin3b-Mediated Membrane Fusion By T14, Munc18, And Complexin, Rajkishor Nishad, Miguel Betancourt-Solis, Himani Dey, Ruth Heidelberger, James A Mcnew

Faculty, Staff and Student Publications

Retinal neurons that form ribbon-style synapses operate over a wide dynamic range, continuously relaying visual information to their downstream targets. The remarkable signaling abilities of these neurons are supported by specialized presynaptic machinery, one component of which is syntaxin3B. Syntaxin3B is an essential t-SNARE protein of photoreceptors and bipolar cells that is required for neurotransmitter release. It has a light-regulated phosphorylation site in its N-terminal domain at T14 that has been proposed to modulate membrane fusion. However, a direct test of the latter has been lacking. Using a well-controlled in vitro fusion assay, we found that a phosphomimetic T14 syntaxin3B …

Enhanced Presynaptic Mitochondrial Energy Production Is Required For Memory Formation, Erica L Underwood, John B Redell, Kimberly N Hood, Mark E Maynard, Michael Hylin, M Neal Waxham, Jing Zhao, Anthony N Moore, Pramod K Dash

Faculty, Staff and Student Publications

Some of the prominent features of long-term memory formation include protein synthesis, gene expression, enhanced neurotransmitter release, increased excitability, and formation of new synapses. As these processes are critically dependent on mitochondrial function, we hypothesized that increased mitochondrial respiration and dynamics would play a prominent role in memory formation. To address this possibility, we measured mitochondrial oxygen consumption (OCR) in hippocampal tissue punches from trained and untrained animals. Our results show that context fear training significantly increased basal, ATP synthesis-linked, and maximal OCR in the Shaffer collateral-CA1 synaptic region, but not in the CA1 cell body layer. These changes were …

Target Cell-Specific Synaptic Dynamics Of Excitatory To Inhibitory Neuron Connections In Supragranular Layers Of Human Neocortex, Mean-Hwan Kim, Cristina Radaelli, Elliot R Thomsen, Deja Monet, Thomas Chartrand, Nikolas L Jorstad, Joseph T Mahoney, Michael J Taormina, Brian Long, Katherine Baker, Trygve E Bakken, Luke Campagnola, Tamara Casper, Michael Clark, Nick Dee, Florence D'Orazi, Clare Gamlin, Brian E Kalmbach, Sara Kebede, Brian R Lee, Lindsay Ng, Jessica Trinh, Charles Cobbs, Ryder P Gwinn, C Dirk Keene, Andrew L Ko, Jeffrey G Ojemann, Daniel L Silbergeld, Staci A Sorensen, Jim Berg, Kimberly A Smith, Philip R Nicovich, Tim Jarsky, Hongkui Zeng, Jonathan T Ting, Boaz P Levi, Ed Lein

Faculty, Staff and Student Publications

Rodent studies have demonstrated that synaptic dynamics from excitatory to inhibitory neuron types are often dependent on the target cell type. However, these target cell-specific properties have not been well investigated in human cortex, where there are major technical challenges in reliably obtaining healthy tissue, conducting multiple patch-clamp recordings on inhibitory cell types, and identifying those cell types. Here, we take advantage of newly developed methods for human neurosurgical tissue analysis with multiple patch-clamp recordings, post-hoc fluorescent in situ hybridization (FISH), machine learning-based cell type classification and prospective GABAergic AAV-based labeling to investigate synaptic properties between pyramidal neurons and PVALB- …

Synaptic Development In Diverse Olfactory Neuron Classes Uses Distinct Temporal And Activity-Related Programs, Michael A. Aimino, Alison T. Depew, Lucas Restrepo, Timothy J. Mosca

Farber Institute for Neuroscience Faculty Papers

Developing neurons must meet core molecular, cellular, and temporal requirements to ensure the correct formation of synapses, resulting in functional circuits. However, because of the vast diversity in neuronal class and function, it is unclear whether or not all neurons use the same organizational mechanisms to form synaptic connections and achieve functional and morphologic maturation. Moreover, it remains unknown whether neurons united in a common goal and comprising the same sensory circuit develop on similar timescales and use identical molecular approaches to ensure the formation of the correct number of synapses. To begin to answer these questions, we took advantage …

Rapid Reconstruction Of Neural Circuits Using Tissue Expansion And Light Sheet Microscopy, Joshua L Lillvis, Hideo Otsuna, Xiaoyu Ding, Igor Pisarev, Takashi Kawase, Jennifer Colonell, Konrad Rokicki, Cristian Goina, Ruixuan Gao, Amy Hu, Kaiyu Wang, John Bogovic, Daniel E Milkie, Linus Meienberg, Brett D Mensh, Edward S Boyden, Stephan Saalfeld, Paul W Tillberg, Barry J Dickson

Faculty, Staff and Student Publications

Brain function is mediated by the physiological coordination of a vast, intricately connected network of molecular and cellular components. The physiological properties of neural network components can be quantified with high throughput. The ability to assess many animals per study has been critical in relating physiological properties to behavior. By contrast, the synaptic structure of neural circuits is presently quantifiable only with low throughput. This low throughput hampers efforts to understand how variations in network structure relate to variations in behavior. For neuroanatomical reconstruction, there is a methodological gulf between electron microscopic (EM) methods, which yield dense connectomes at considerable …

Impairment Of Trkb-Psd-95 Signaling In Angelman Syndrome, Cong Cao, Mengia S. Rioult-Pedotti, Paolo Migani, Crystal J. Yu, Rakesh Tiwari, Keykavous Parang, Mark R. Spaller

Dartmouth Scholarship

Angelman syndrome (AS) is a neurodevelopment disorder characterized by severe cognitive impairment and a high rate of autism. AS is caused by disrupted neuronal expression of the maternally inherited Ube3A ubiquitin protein ligase, required for the proteasomal degradation of proteins implicated in synaptic plasticity, such as the activity-regulated cytoskeletal-associated protein (Arc/Arg3.1). Mice deficient in maternal Ube3A express elevated levels of Arc in response to synaptic activity, which coincides with severely impaired long-term potentiation (LTP) in the hippocampus and deficits in learning behaviors. In this study, we sought to test whether elevated levels of Arc interfere with brain-derived neurotrophic factor (BDNF) …

Inhibition Of Soluble Tumor Necrosis Factor Ameliorates Synaptic Alterations And Ca2+ Dysregulation In Aged Rats, Diana M. Sama, Hafiz Mohmmad Abdul, Jennifer L. Furman, Irina A. Artiushin, David E. Szymkowski, Stephen W. Scheff, Christopher M. Norris

Graduate Center for Gerontology Faculty Publications

The role of tumor necrosis factor α (TNF) in neural function has been investigated extensively in several neurodegenerative conditions, but rarely in brain aging, where cognitive and physiologic changes are milder and more variable. Here, we show that protein levels for TNF receptor 1 (TNFR1) are significantly elevated in the hippocampus relative to TNF receptor 2 (TNFR2) in aged (22 months) but not young adult (6 months) Fischer 344 rats. To determine if altered TNF/TNFR1 interactions contribute to key brain aging biomarkers, aged rats received chronic (4-6 week) intracranial infusions of XPro1595: a soluble dominant negative TNF that preferentially inhibits …