16 results on '"Sabbagh, Ubadah"'
Search Results
2. The postdoc experience is broken. Funders such as the NIH must help to reimagine it
- Author
-
Sabbagh, Ubadah
- Published
- 2023
- Full Text
- View/download PDF
3. Retinal inputs signal astrocytes to recruit interneurons into visual thalamus
- Author
-
Su, Jianmin, Charalambakis, Naomi E., Sabbagh, Ubadah, Somaiya, Rachana D., Monavarfeshani, Aboozar, Guido, William, and Fox, Michael A.
- Published
- 2020
4. Retinal Input Is Required for the Maintenance of Neuronal Laminae in the Ventrolateral Geniculate Nucleus.
- Author
-
Stebbins, Katelyn, Somaiya, Rachana Deven, Sabbagh, Ubadah, Khaksar, Parsa, Yanping Liang, Jianmin Su, and Fox, Michael A.
- Published
- 2024
- Full Text
- View/download PDF
5. A One Health overview, facilitating advances in comparative medicine and translational research
- Author
-
Stroud, Cheryl, Dmitriev, Igor, Kashentseva, Elena, Bryan, Jeffrey N., Curiel, David T., Rindt, Hans, Reinero, Carol, Henry, Carolyn J., Bergman, Philip J., Mason, Nicola J., Gnanandarajah, Josephine S., Engiles, Julie B., Gray, Falon, Laughlin, Danielle, Gaurnier-Hausser, Anita, Wallecha, Anu, Huebner, Margie, Paterson, Yvonne, O’Connor, Daniel, Treml, Laura S., Stannard, James P., Cook, James L., Jacobs, Marc, Wyckoff, Gerald J., Likins, Lee, Sabbagh, Ubadah, Skaff, Andrew, Guloy, Amado S., Hays, Harlen D., LeBlanc, Amy K., Coates, Joan R., Katz, Martin L., Lyons, Leslie A., Johnson, Gayle C., Johnson, Gary S., O’Brien, Dennis P., Duan, Dongsheng, Calvet, James P., Gandolfi, Barbara, Baron, David A., Weiss, Mark L., Webster, Debra A., Karanu, Francis N., Robb, Edward J., and Harman, Robert J.
- Published
- 2016
- Full Text
- View/download PDF
6. Science is better when we open our doors to immigrants
- Author
-
Sabbagh, Ubadah
- Subjects
Epidemics -- Control -- Social aspects -- Prevention -- United States ,President of the United States -- Social policy -- Laws, regulations and rules -- Social aspects ,Work visas -- Laws, regulations and rules -- Social aspects ,Immigrants -- Emigration and immigration -- Laws, regulations and rules -- Social aspects ,COVID-19 -- Social aspects -- Prevention ,Scientists -- Emigration and immigration -- Laws, regulations and rules -- Social aspects ,Government regulation ,General interest ,News, opinion and commentary - Abstract
Byline: Ubadah Sabbagh For Print Use Only. I took a stroll the other day through my research institute, passing by six labs in one hallway. Of course, we aren't operating [...]
- Published
- 2020
7. Development of astrocyte morphology and function in mouse visual thalamus.
- Author
-
Somaiya, Rachana D., Huebschman, Natalie A., Chaunsali, Lata, Sabbagh, Ubadah, Carrillo, Gabriela L., Tewari, Bhanu P., and Fox, Michael A.
- Abstract
The rodent visual thalamus has served as a powerful model to elucidate the cellular and molecular mechanisms that underlie sensory circuit formation and function. Despite significant advances in our understanding of the role of axon‐target interactions and neural activity in orchestrating circuit formation in visual thalamus, the role of non‐neuronal cells, such as astrocytes, is less clear. In fact, we know little about the transcriptional identity and development of astrocytes in mouse visual thalamus. To address this gap in knowledge, we studied the expression of canonical astrocyte molecules in visual thalamus using immunostaining, in situ hybridization, and reporter lines. While our data suggests some level of heterogeneity of astrocytes in different nuclei of the visual thalamus, the majority of thalamic astrocytes appeared to be labeled in Aldh1l1‐EGFP mice. This led us to use this transgenic line to characterize the neonatal and postnatal development of these cells in visual thalamus. Our data show that not only have the entire cohort of astrocytes migrated into visual thalamus by eye‐opening but they also have acquired their adult‐like morphology, even while retinogeniculate synapses are still maturing. Furthermore, ultrastructural, immunohistochemical, and functional approaches revealed that by eye‐opening, thalamic astrocytes ensheathe retinogeniculate synapses and are capable of efficient uptake of glutamate. Taken together, our results reveal that the morphological, anatomical, and functional development of astrocytes in visual thalamus occurs prior to eye‐opening and the emergence of experience‐dependent visual activity. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
8. Diverse GABAergic neurons organize into subtype‐specific sublaminae in the ventral lateral geniculate nucleus.
- Author
-
Sabbagh, Ubadah, Govindaiah, Gubbi, Somaiya, Rachana D., Ha, Ryan V., Wei, Jessica C., Guido, William, and Fox, Michael A.
- Subjects
- *
LATERAL geniculate body , *GABAERGIC neurons , *AFFERENT pathways , *OPTICAL information processing , *IN situ hybridization , *RETINA , *VISUAL cortex - Abstract
In the visual system, retinal axons convey visual information from the outside world to dozens of distinct retinorecipient brain regions and organize that information at several levels, including either at the level of retinal afferents, cytoarchitecture of intrinsic retinorecipient neurons, or a combination of the two. Two major retinorecipient nuclei which are densely innervated by retinal axons are the dorsal lateral geniculate nucleus, which is important for classical image‐forming vision, and ventral LGN (vLGN), which is associated with non‐image‐forming vision. The neurochemistry, cytoarchitecture, and retinothalamic connectivity in vLGN remain unresolved, raising fundamental questions of how it receives and processes visual information. To shed light on these important questions, used in situ hybridization, immunohistochemistry, and genetic reporter lines to identify and characterize novel neuronal cell types in mouse vLGN. Not only were a high percentage of these cells GABAergic, we discovered transcriptomically distinct GABAergic cell types reside in the two major laminae of vLGN, the retinorecipient, external vLGN (vLGNe) and the non‐retinorecipient, internal vLGN (vLGNi). Furthermore, within vLGNe, we identified transcriptionally distinct subtypes of GABAergic cells that are distributed into four adjacent sublaminae. Using trans‐synaptic viral tracing and in vitro electrophysiology, we found cells in each these vLGNe sublaminae receive monosynaptic inputs from retina. These results not only identify novel subtypes of GABAergic cells in vLGN, they suggest the subtype‐specific laminar distribution of retinorecipient cells in vLGNe may be important for receiving, processing, and transmitting light‐derived signals in parallel channels of the subcortical visual system. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
9. A cell--ECM mechanism for connecting the ipsilateral eye to the brain.
- Author
-
Jianmin Su, Sabbagh, Ubadah, Yanping Liang, Olejníková, Lucie, Dixon, Karen G., Russell, Ashley L., Jiang Chen, Pan, Yuchin Albert, Triplett, Jason W., and Fox, Michael A.
- Subjects
- *
RETINAL ganglion cells , *SUPERIOR colliculus , *VISUAL pathways , *EXTRACELLULAR matrix , *AXONS , *COMMERCIAL products - Abstract
Information about features in the visual world is parsed by circuits in the retina and is then transmitted to the brain by distinct subtypes of retinal ganglion cells (RGCs). Axons from RGC subtypes are stratified in retinorecipient brain nuclei, such as the superior colliculus (SC), to provide a segregated relay of parallel and feature-specific visual streams. Here, we sought to identify the molecular mechanisms that direct the stereotyped laminar targeting of these axons. We focused on ipsilateral-projecting subtypes of RGCs (ipsiRGCs) whose axons target a deep SC sublamina. We identified an extracellular glycoprotein, Nephronectin (NPNT), whose expression is restricted to this ipsiRGC-targeted sublamina. SC-derived NPNT and integrin receptors expressed by ipsiRGCs are both required for the targeting of ipsiRGC axons to the deep sublamina of SC. Thus, a cell--extracellular matrix (ECM) recognition mechanism specifies precise laminar targeting of ipsiRGC axons and the assembly of eye-specific parallel visual pathways. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
10. Retinal inputs signal astrocytes to recruit interneurons into visual thalamus.
- Author
-
Jianmin Su, Charalambakis, Naomi E., Sabbagh, Ubadah, Somaiya, Rachana D., Monavarfeshani, Aboozar, Guido, William, and Fox, Michael A.
- Subjects
THALAMUS ,THALAMIC nuclei ,FIBROBLAST growth factors ,RETINAL ganglion cells ,INNERVATION - Abstract
Inhibitory interneurons comprise a fraction of the total neurons in the visual thalamus but are essential for sharpening receptive field properties and improving contrast-gain of retinogeniculate transmission. During early development, these interneurons undergo long-range migration from germinal zones, a process regulated by the innervation of the visual thalamus by retinal ganglion cells. Here, using transcriptomic approaches, we identified a motogenic cue, fibroblast growth factor 15 (FGF15), whose expression in the visual thalamus is regulated by retinal input. Targeted deletion of functional FGF15 in mice led to a reduction in thalamic GABAergic interneurons similar to that observed in the absence of retinal input. This loss may be attributed, at least in part, to misrouting of interneurons into nonvisual thalamic nuclei. Unexpectedly, expression analysis revealed that FGF15 is generated by thalamic astrocytes and not retino-recipient neurons. Thus, these data show that retinal inputs signal through astrocytes to direct the longrange recruitment of interneurons into the visual thalamus. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
11. Neural Polyamory: One Cell Forms Meaningful Connections with Hundreds of Partners
- Author
-
Rasmussen, Rune and Sabbagh, Ubadah
- Published
- 2020
- Full Text
- View/download PDF
12. Distribution and development of molecularly distinct perineuronal nets in visual thalamus.
- Author
-
Sabbagh, Ubadah, Monavarfeshani, Aboozar, Su, Kaiwen, Zabet‐Moghadam, Masoud, Cole, James, Carnival, Eric, Su, Jianmin, Mirzaei, Mehdi, Gupta, Vivek, Salekdeh, Ghasem Hosseini, and Fox, Michael A.
- Subjects
- *
THALAMUS , *PERINEURONAL nets , *GENE expression , *BRAIN , *CHONDROITIN sulfate proteoglycan - Abstract
Visual information is detected by the retina and transmitted into the brain by retinal ganglion cells. In rodents, the visual thalamus is a major recipient of retinal ganglion cells axons and is divided into three functionally distinct nuclei: the dorsal lateral geniculate nucleus (dLGN), ventral LGN (vLGN), and intergeniculate leaflet. Despite being densely innervated by retinal input, each nucleus in rodent visual thalamus possesses diverse molecular profiles which underpin their unique circuitry and cytoarchitecture. Here, we combined large‐scale unbiased proteomic and transcriptomic analyses to elucidate the molecular expression profiles of the developing mouse dLGN and vLGN. We identified several extracellular matrix proteins as differentially expressed in these regions, particularly constituent molecules of perineuronal nets (PNNs). Remarkably, we discovered at least two types of molecularly distinct Aggrecan‐rich PNN populations in vLGN, exhibiting non‐overlapping spatial, temporal, and cell‐type specific expression patterns. The mechanisms responsible for the formation of these two populations of PNNs also differ as the formation of Cat315+PNNs (but not WFA+PNNs) required input from the retina. This study is first to suggest that cell type‐ and molecularly specific supramolecular assemblies of extracellular matrix may play important roles in the circuitry associated with the subcortical visual system and in the processing of visual information. Open science badges: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/. Cover Image for this issue: doi: 10.1111/jnc.14203. The rodent dorsal and ventral lateral geniculate nuclei (dLGN and vLGN, respectively) both receive dense retinal input, yet exhibit unique circuitry and cytoarchitecture. Through combining proteomic and transcriptomic analyses, we discovered the presence of at least two types of molecularly distinct Aggrecan‐rich perineuronal nets (PNNs) in vLGN, each exhibiting non‐overlapping spatial, temporal, and cell‐type specific expression patterns. Further, by genetically removing retinal input, we showed activity‐dependent regulation of one type of PNN and not the other. Cover Image for this issue: doi: 10.1111/jnc.14203. Open Science: This manuscript was awarded with the Open Materials Badge. For more information see: https://cos.io/our-services/open-science-badges/ [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
13. Region- and Cell-Specific Expression of Transmembrane Collagens in Mouse Brain.
- Author
-
Monavarfeshani, Aboozar, Knill, Courtney N., Sabbagh, Ubadah, Jianmin Su, and Fox, Michael A.
- Subjects
COLLAGEN ,BRAIN physiology ,LABORATORY mice - Abstract
Unconventional collagens are nonfribrillar proteins that not only contribute to the structure of extracellular matrices but exhibit unique bio-activities. Although roles for unconventional collagens have been well-established in the development and function of non-neural tissues, only recently have studies identified roles for these proteins in brain development, and more specifically, in the formation and refinement of synaptic connections between neurons. Still, our understanding of the full cohort of unconventional collagens that are generated in the mammalian brain remains unclear. Here, we sought to address this gap by assessing the expression of transmembrane collagens (i.e., collagens XIII, XVII, XXIII and XXV) in mouse brain. Using quantitative PCR and in situ hybridization (ISH), we demonstrate both regionand cell-specific expression of these unique collagens in the developing brain. For the two most highly expressed transmembrane collagens (i.e., collagen XXIII and XXV), we demonstrate that they are expressed by select subsets of neurons in different parts of the brain. For example, collagen XXIII is selectively expressed by excitatory neurons in the mitral/tufted cell layer of the accessory olfactory bulb (AOB) and by cells in the inner nuclear layer (INL) of the retina. On the other hand, collagen XXV, which is more broadly expressed, is generated by subsets of excitatory neurons in the dorsal thalamus and midbrain and by inhibitory neurons in the retina, ventral thalamus and telencephalon. Not only is col25a1 expression present in retina, it appears specifically enriched in retino-recipient nuclei within the brain (including the suprachiasmatic nucleus (SCN), lateral geniculate complex, olivary pretectal nucleus (OPN) and superior colliculus). Taken together, the distinct regionand cell-specific expression patterns of transmembrane collagens suggest that this family of unconventional collagens may play unique, yet-to-be identified roles in brain development and function. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
14. Not a one-trick pony: Diverse connectivity and functions of the rodent lateral geniculate complex.
- Author
-
MONAVARFESHANI, ABOOZAR, SABBAGH, UBADAH, and FOX, MICHAEL A.
- Published
- 2017
- Full Text
- View/download PDF
15. Identification and Evolutionary Analysis of Potential Candidate Genes in a Human Eating Disorder.
- Author
-
Sabbagh, Ubadah, Mullegama, Saman, and Wyckoff, Gerald J.
- Subjects
- *
EATING disorders , *OBESITY genetics , *NIGHT eating syndrome , *CHI-squared test , *BIOLOGICAL evolution , *FISHER exact test , *GENES , *GENETIC polymorphisms , *META-analysis , *METABOLISM , *GENETIC mutation , *PROBABILITY theory , *RESEARCH funding , *SLEEP , *STATISTICS , *T-test (Statistics) , *DATA analysis , *MAXIMUM likelihood statistics , *NEURAL pathways , *DATA analysis software , *DESCRIPTIVE statistics , *GENETICS - Abstract
The purpose of this study was to find genes linked with eating disorders and associated with both metabolic and neural systems. Our operating hypothesis was that there are genetic factors underlying some eating disorders resting in both those pathways. Specifically, we are interested in disorders that may rest in both sleep and metabolic function, generally called Night Eating Syndrome (NES). A meta-analysis of the Gene Expression Omnibus targeting the mammalian nervous system, sleep, and obesity studies was performed, yielding numerous genes of interest. Through a text-based analysis of the results, a number of potential candidate genes were identified. VGF, in particular, appeared to be relevant both to obesity and, broadly, to brain or neural development. VGF is a highly connected protein that interacts with numerous targets via proteolytically digested peptides. We examined VGF from an evolutionary perspective to determine whether other available evidence supported a role for the gene in human disease. We conclude that some of the already identified variants in VGF from human polymorphism studies may contribute to eating disorders and obesity. Our data suggest that there is enough evidence to warrant eGWAS and GWAS analysis of these genes in NES patients in a case-control study. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
16. Retinal input is required for the maintenance of neuronal laminae in the ventral lateral geniculate nucleus.
- Author
-
Stebbins K, Somaiya RD, Sabbagh U, Liang Y, Su J, and Fox MA
- Abstract
Retinal ganglion cell (RGC) axons provide direct input into several nuclei of the mouse visual thalamus, including the dorsal lateral geniculate nucleus (dLGN), which is important for classical image-forming vision, and the ventral lateral geniculate nucleus (vLGN), which is associated with non-image-forming vision. Through both activity- and morphogen-dependent mechanisms, retinal inputs play important roles in the development of dLGN, including the refinement of retinal projections, morphological development of thalamocortical relay cells (TRCs), the timing of corticogeniculate innervation, and the recruitment of inhibitory interneurons from progenitor zones. In contrast, little is known about the role of retinal inputs in the development of vLGN. Grossly, vLGN is divided into two domains, the retinorecipient external vLGN (vLGNe) and the non-retinorecipient internal vLGN (vLGNi). We previously found that vLGNe consists of transcriptionally distinct GABAergic subtypes that are distributed into at least four adjacent laminae. At present, it remains unclear whether retinal inputs influence the development of these cell-specific neuronal laminae in vLGNe. Here, we elucidated the developmental timeline for the formation and maintenance of these laminae in the mouse vLGNe and results indicate that these laminae are specified at or before birth, well before eye-opening and the emergence of experience-dependent visual activity. We observed that mutant mice without retinal inputs have a normal laminar distribution of GABAergic cells at birth; however, after the first week of postnatal development, these mutants exhibited a dramatic disruption in the laminar organization of inhibitory neurons and clear boundaries between vLGNe and vLGNi. Overall, our results show that while the formation of cell type-specific layers in vLGNe does not depend on RGC inputs, retinal signals are critical for their maintenance.
- Published
- 2024
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.