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The Eagleville Times,Volume 6, Issue 19, Debbie Ryan

Eagleville Times

No abstract provided.

Molecular And Macromolecular Alterations Of Recombinant Adenoviral Vectors Do Not Resolve Changes In Hepatic Drug Metabolism During Infection, Shellie M Callahan, Piyanuch Wonganan, Maria A Croyle

Faculty, Staff and Student Publications

In this report we test the hypothesis that long-term virus-induced alterations in CYP occur from changes initiated by the virus that may not be related to the immune response. Enzyme activity, protein expression and mRNA of CYP3A2, a correlate of human CYP3A4, and CYP2C11, responsive to inflammatory mediators, were assessed 0.25, 1, 4, and 14 days after administration of several different recombinant adenoviruses at a dose of 5.7 x 1012 virus particles (vp)/kg to male Sprague Dawley rats. Wild type adenovirus, containing all viral genes, suppressed CYP3A2 and 2C11 activity by 37% and 39%, respectively within six hours. Levels fell …

Substance Use Among Persons With Syphilis During Pregnancy — Arizona And Georgia, 2018–2021, Lingpeng Cheng, Qin Fang, Sanket Shah, Ivo C Atanasov, Z Hong Zhou

Faculty, Staff and Student Publications

Grass carp reovirus (GCRV) is a member of the Aquareovirus genus of the family Reoviridae, a large family of double-stranded RNA (dsRNA) viruses infecting plants, insects, fishes and mammals. We report the first subnanometer-resolution three-dimensional structures of both GCRV core and virion by cryoelectron microscopy. These structures have allowed the delineation of interactions among the over 1000 molecules in this enormous macromolecular machine and a detailed comparison with other dsRNA viruses at the secondary-structure level. The GCRV core structure shows that the inner proteins have strong structural similarities with those of orthoreoviruses even at the level of secondary-structure elements, indicating …

Missense Mutation In Exon 2 Of Slc36a1 Responsible For Champagne Dilution In Horses, Deborah Cook, Samantha Brooks, Rebecca Bellone, Ernest Bailey

Veterinary Science Faculty Publications

Champagne coat color in horses is controlled by a single, autosomal-dominant gene (CH). The phenotype produced by this gene is valued by many horse breeders, but can be difficult to distinguish from the effect produced by the Cream coat color dilution gene (CR). Three sires and their families segregating for CH were tested by genome scanning with microsatellite markers. The CH gene was mapped within a 6 cM region on horse chromosome 14 (LOD = 11.74 for theta = 0.00). Four candidate genes were identified within the region, namely SPARC [Secreted protein, acidic, cysteine-rich (osteonectin)], SLC36A1 (Solute Carrier 36 family …

Deregulation Of Muc4 In Gastric Adenocarcinoma: Potential Pathobiological Implication In Poorly Differentiated Non-Signet Ring Cell Type Gastric Cancer., S. Senapati, P. Chaturvedi, P. Sharma, G Venkatraman, Jane L. Meza, W. El-Rifai, H. K. Roy, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

MUC4 is a large, heavily glycosylated transmembrane mucin, that is implicated in the pathogenesis of various types of cancers. To date, no extensive study has been done to check the expression and functional significance of MUC4 in different types of gastric adenocarcinomas. Here, we report the expression profile of MUC4 in gastric adenocarcinomas and its function in poorly differentiated gastric non-signet ring cell carcinoma (non-SRCC) type cells. Immunohistochemical analysis using tissue microarray (TMA) showed a significant difference in MUC4 expression between normal adjacent (n = 45) and gastric adenocarcinoma (n = 83; P < 0.001). MUC4 expression was not associated with tumour type, stage or with the degree of differentiation. To gain further insight into the significance of MUC4 expression in gastric non-SRCC cells, MUC4 was ectopically expressed in AGS, a poorly differentiated gastric non-signet ring cell line. The MUC4 overexpressing cells (AGS-MUC4) showed a significant increase (P < 0.005) in cell motility and a decrease in cellular aggregation as compared with the vector-transfected cells. Furthermore, in vivo tumorigenicity analysis revealed that animals transplanted with the MUC4 overexpressing cells (AGS-MUC4) had a greater incidence of tumours (83%) in comparison to empty vector control (17%). In addition, the expression of MUC4 resulted in enhanced expression of total cellular ErbB2 and phosphorylated ErbB2. In conclusion, our results showed that MUC4 is overexpressed in gastric adenocarcinoma tissues, and that it has a role in promoting aggressive properties in poorly differentiated gastric non-SRCC cells through the activation of the ErbB2 oncoprotein.

Molecular Mechanisms Underlying A Cellular Analog Of Operant Reward Learning, Fred D Lorenzetti, Douglas A Baxter, John H Byrne

Faculty, Staff and Student Publications

Operant conditioning is a ubiquitous but mechanistically poorly understood form of associative learning in which an animal learns the consequences of its behavior. Using a single-cell analog of operant conditioning in neuron B51 of Aplysia, we examined second-messenger pathways engaged by activity and reward and how they may provide a biochemical association underlying operant learning. Conditioning was blocked by Rp-cAMP, a peptide inhibitor of PKA, a PKC inhibitor, and by expressing a dominant-negative isoform of Ca2+-dependent PKC (apl-I). Thus, both PKA and PKC were necessary for operant conditioning. Injection of cAMP into B51 mimicked the effects of operant conditioning. Activation …

The Fgf System Has A Key Role In Regulating Vascular Integrity, Masahiro Murakami, Loc T. Nguyen, Zhen W. Zhang, Karen L. Moodie, Pater Carmellet, Radu V. Stan, Michael Simons

Dartmouth Scholarship

The integrity of the endothelial monolayer is essential to blood vessel homeostasis and active regulation of endothelial permeability. The FGF system plays important roles in a wide variety of physiologic and pathologic conditions; however, its role in the adult vasculature has not been defined. To assess the role of the FGF system in the adult endothelial monolayer, we disrupted FGF signaling in bovine aortic endothelial cells and human saphenous vein endothelial cells in vitro and in adult mouse and rat endothelial cells in vivo using soluble FGF traps or a dominant inhibitor of all FGF receptors. The inhibition of FGF …

The Eagleville Times,Volume 6, Issue 17, Debbie Ryan

Eagleville Times

No abstract provided.

Experimental Optic Neuritis Induced By A Demyelinating Strain Of Mouse Hepatitis Virus., Kenneth S. Shindler, Lawrence C. Kenyon, Mahasweta Dutt, Susan T. Hingley, Jayasri Das Sarma

Department of Neurology Faculty Papers

Optic neuritis (ON), an inflammatory demyelinating optic nerve disease, occurs in multiple sclerosis (MS). Pathological mechanisms and potential treatments for ON have been studied via experimental autoimmune MS models. However, evidence suggests that virus-induced inflammation is a likely etiology triggering MS and ON; experimental virus-induced ON models are therefore required. We demonstrate that MHV-A59, a mouse hepatitis virus (MHV) strain that causes brain and spinal cord inflammation and demyelination, induces ON by promoting mixed inflammatory cell infiltration. In contrast, MHV-2, a nondemyelinating MHV strain, does not induce ON. Results reveal a reproducible virus-induced ON model important for the evaluation of …

Spatiotemporally Distributed Frontotemporal Networks For Sentence Reading, Sidney R. Lehky, Xinmiao Peng, Carrie J. Mcadams, Anne B. Sereno

Faculty, Staff and Student Publications

BACKGROUND: A key aspect of representations for object recognition and scene analysis in the ventral visual stream is the spatial frame of reference, be it a viewer-centered, object-centered, or scene-based coordinate system. Coordinate transforms from retinocentric space to other reference frames involve combining neural visual responses with extraretinal postural information.

METHODOLOGY/PRINCIPAL FINDINGS: We examined whether such spatial information is available to anterior inferotemporal (AIT) neurons in the macaque monkey by measuring the effect of eye position on responses to a set of simple 2D shapes. We report, for the first time, a significant eye position effect in over 40% of …

A Functional Collagen Adhesin Gene, Acm, In Clinical Isolates Of Enterococcus Faecium Correlates With The Recent Success Of This Emerging Nosocomial Pathogen, Sreedhar R Nallapareddy, Kavindra V Singh, Pablo C Okhuysen, Barbara E Murray

Faculty, Staff and Student Publications

Enterococcus faecium recently evolved from a generally avirulent commensal into a multidrug-resistant health care-associated pathogen causing difficult-to-treat infections, but little is known about the factors responsible for this change. We previously showed that some E. faecium strains express a cell wall-anchored collagen adhesin, Acm. Here we analyzed 90 E. faecium isolates (99% acm(+)) and found that the Acm protein was detected predominantly in clinically derived isolates, while the acm gene was present as a transposon-interrupted pseudogene in 12 of 47 isolates of nonclinical origin. A highly significant association between clinical (versus fecal or food) origin and collagen adherence (P

Contribution Of The Collagen Adhesin Acm To Pathogenesis Of Enterococcus Faecium In Experimental Endocarditis, Sreedhar R Nallapareddy, Kavindra V Singh, Barbara E Murray

Faculty, Staff and Student Publications

Enterococcus faecium is a multidrug-resistant opportunist causing difficult-to-treat nosocomial infections, including endocarditis, but there are no reports experimentally demonstrating E. faecium virulence determinants. Our previous studies showed that some clinical E. faecium isolates produce a cell wall-anchored collagen adhesin, Acm, and that an isogenic acm deletion mutant of the endocarditis-derived strain TX0082 lost collagen adherence. In this study, we show with a rat endocarditis model that TX0082 Deltaacm::cat is highly attenuated versus wild-type TX0082, both in established (72 h) vegetations (P < 0.0001) and for valve colonization 1 and 3 hours after infection (P or=50-fold reduction relative to an Acm producer) were found in three of these five nonadherent isolates, including the sequenced strain TX0016, by quantitative reverse transcription-PCR, indicating that acm transcription is downregulated in vitro in these isolates. However, examination of TX0016 cells obtained directly from infected rat vegetations by flow cytometry showed that Acm was present on 40% of cells grown during infection. Finally, we demonstrated a significant reduction in E. faecium collagen adherence by affinity-purified anti-Acm antibodies from E. faecium endocarditis patient sera, suggesting that Acm may be a potential immunotarget for strategies to control this emerging pathogen.

Decreased Expression Of Caveolin 1 In Patients With Systemic Sclerosis: Crucial Role In The Pathogenesis Of Tissue Fibrosis., Francesco Del Galdo, Federica Sotgia, Cecilia J. De Almeida, Jean-Francois Jasmin, Megan Musick, Michael P. Lisanti, Sergio A. Jimenez

Department of Medicine Faculty Papers

OBJECTIVE: Recent studies have implicated caveolin 1 in the regulation of transforming growth factor beta (TGFbeta) downstream signaling. Given the crucial role of TGFbeta in the pathogenesis of systemic sclerosis (SSc), we sought to determine whether caveolin 1 is also involved in the pathogenesis of tissue fibrosis in SSc. We analyzed the expression of CAV1 in affected SSc tissues, studied the effects of lack of expression of CAV1 in vitro and in vivo, and analyzed the effects of restoration of caveolin 1 function on the fibrotic phenotype of SSc fibroblasts in vitro.

METHODS: CAV1 expression in tissues was analyzed by …

Accelerated High Fidelity Prion Amplification Within And Across Prion Species Barriers, Kristi M. Green, Joaquín Castilla, Tanya S. Seward, Dana L. Napier, Jean E. Jewell, Claudio Soto, Glenn C. Telling

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Experimental obstacles have impeded our ability to study prion transmission within and, more particularly, between species. Here, we used cervid prion protein expressed in brain extracts of transgenic mice, referred to as Tg(CerPrP), as a substrate for in vitro generation of chronic wasting disease (CWD) prions by protein misfolding cyclic amplification (PMCA). Characterization of this infectivity in Tg(CerPrP) mice demonstrated that serial PMCA resulted in the high fidelity amplification of CWD prions with apparently unaltered properties. Using similar methods to amplify mouse RML prions and characterize the resulting novel cervid prions, we show that serial PMCA abrogated a transmission barrier …

An Sp1/Sp3 Binding Polymorphism Confers Methylation Protection, Yanis A. Boumber, Yutaka Kondo, Xuqi Chen, Lanlan Shen, Yi Guo, Carmen Tellez, Marcos R H Estécio, Saira Ahmed, Jean-Pierre J. Issa

Faculty, Staff and Student Publications

Hundreds of genes show aberrant DNA hypermethylation in cancer, yet little is known about the causes of this hypermethylation. We identified RIL as a frequent methylation target in cancer. In search for factors that influence RIL hypermethylation, we found a 12-bp polymorphic sequence around its transcription start site that creates a long allele. Pyrosequencing of homozygous tumors revealed a 2.1-fold higher methylation for the short alleles (P<0.001). Bisulfite sequencing of cancers heterozygous for RIL showed that the short alleles are 3.1-fold more methylated than the long (P<0.001). The comparison of expression levels between unmethylated long and short EBV-transformed cell lines showed no difference in expression in vivo. Electrophorectic mobility shift assay showed that the inserted region of the long allele binds Sp1 and Sp3 transcription factors, a binding that is absent in the short allele. Transient transfection of RIL allele-specific transgenes showed no effects of the additional Sp1 site on transcription early on. However, stable transfection of methylation-seeded constructs showed gradually decreasing transcription levels from the short allele with eventual spreading of de novo methylation. In contrast, the long allele showed stable levels of expression over time as measured by luciferase and approximately 2-3-fold lower levels of methylation by bisulfite sequencing (P<0.001), suggesting that the polymorphic Sp1 site protects against time-dependent silencing. Our finding demonstrates that, in some genes, hypermethylation in cancer is dictated by protein-DNA interactions at the promoters and provides a novel mechanism by which genetic polymorphisms can influence an epigenetic state.

The Eagleville Times,Volume 6, Issue 16, Debbie Ryan

Eagleville Times

No abstract provided.

Cd5 Plays An Inhibitory Role In The Suppressive Function Of Murine Cd4(+) Cd25(+) T(Reg) Cells., Trivikram Dasu, Joseph E Qualls, Halide Tuna, Chander Raman, Donald A Cohen, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

A subset of CD4(+) T cells, the CD4(+) CD25(+) regulatory T (T(reg)) cells in the lymphoid organs and peripheral blood are known to possess suppressive function. Previous in vitro and in vivo studies have indicated that T cell receptor (TCR) signal is required for development of such 'natural regulatory (T(reg)) cells' and for activation of the effector function of CD4(+) CD25(+) regulatory T cells. CD5 is a cell surface molecule present on all T cells and a subtype of B lymphocytes, the B-1 cells, primarily localized to coelomic cavities, Peyer's patches, tonsils and spleen. CD5 acts as a negative regulator …

Cd5 Plays An Inhibitory Role In The Suppressive Function Of Murine Cd4+ Cd25+ TReg Cells, Trivikram Dasu, Joseph E. Qualls, Halide Tuna, Chander Raman, Donald A. Cohen, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

A subset of CD4⁺ T cells, the CD4⁺ CD25⁺ regulatory T (T_reg) cells in the lymphoid organs and peripheral blood are known to possess suppressive function. Previous in vitro and in vivo studies have indicated that T cell receptor (TCR) signal is required for development of such ‘natural regulatory (T_reg) cells’ and for activation of the effector function of CD4⁺ CD25⁺ regulatory T cells. CD5 is a cell surface molecule present on all T cells and a subtype of B lymphocytes, the B-1 cells, primarily localized to coelomic cavities, Peyer's patches, …

A Protein Methylation Pathway In Chlamydomonas Flagella Is Active During Flagellar Resorption, Mark J. Schneider, Megan Ulland, Roger D. Sloboda

Dartmouth Scholarship

During intraflagellar transport (IFT), the regulation of motor proteins, the loading and unloading of cargo and the turnover of flagellar proteins all occur at the flagellar tip. To begin an analysis of the protein composition of the flagellar tip, we used difference gel electrophoresis to compare long versus short (i.e., regenerating) flagella. The concentration of tip proteins should be higher relative to that of tubulin (which is constant per unit length of the flagellum) in short compared with long flagella. One protein we have identified is the cobalamin-independent form of methionine synthase (MetE). Antibodies to MetE label flagella in a …

A Cyclin D1/Microrna 17/20 Regulatory Feedback Loop In Control Of Breast Cancer Cell Proliferation., Zuoren Yu, Chenguang Wang, Min Wang, Zhiping Li, Mathew C Casimiro, Manran Liu, Kongming Wu, James Whittle, Xiaoming Ju, Terry Hyslop, Peter Mccue, Richard G Pestell

Kimmel Cancer Center Faculty Papers

Decreased expression of specific microRNAs (miRNAs) occurs in human tumors, which suggests a function for miRNAs in tumor suppression. Herein, levels of the miR-17-5p/miR-20a miRNA cluster were inversely correlated to cyclin D1 abundance in human breast tumors and cell lines. MiR-17/20 suppressed breast cancer cell proliferation and tumor colony formation by negatively regulating cyclin D1 translation via a conserved 3' untranslated region miRNA-binding site, thereby inhibiting serum-induced S phase entry. The cell cycle effect of miR-17/20 was abrogated by cyclin D1 siRNA and in cyclin D1-deficient breast cancer cells. Mammary epithelial cell-targeted cyclin D1 expression induced miR-17-5p and miR-20a expression …

The Aryl Hydrocarbon Receptor Binds To E2f1 And Inhibits E2f1-Induced Apoptosis., Jennifer L Marlowe, Yunxia Fan, Xiaoqing Chang, Li Peng, Erik S Knudsen, Ying Xia, Alvaro Puga

Kimmel Cancer Center Faculty Papers

Cellular stress by DNA damage induces checkpoint kinase-2 (CHK2)-mediated phosphorylation and stabilization of the E2F1 transcription factor, leading to induction of apoptosis by activation of a subset of proapoptotic E2F1 target genes, including Apaf1 and p73. This report characterizes an interaction between the aryl hydrocarbon (Ah) receptor (AHR), a ligand-activated transcription factor, and E2F1 that results in the attenuation of E2F1-mediated apoptosis. In Ahr(-/-) fibroblasts stably transfected with a doxycycline-regulated AHR expression vector, inhibition of AHR expression causes a significant elevation of oxidative stress, gammaH2A.X histone phosphorylation, and E2F1-dependent apoptosis, which can be blocked by small interfering RNA-mediated knockdown of …

Structures And Functions Of The Normal And Injured Human Olfactory Epithelium, Jonathan P Schuermann, Jianwen Jiang, Jorge Cuellar, Oscar Llorca, Liping Wang, Luis E Gimenez, Suping Jin, Alexander B Taylor, Borries Demeler, Kevin A Morano, P John Hart, Jose M Valpuesta, Eileen M Lafer, Rui Sousa

Faculty, Staff and Student Publications

Hsp70s mediate protein folding, translocation, and macromolecular complex remodeling reactions. Their activities are regulated by proteins that exchange ADP for ATP from the nucleotide-binding domain (NBD) of the Hsp70. These nucleotide exchange factors (NEFs) include the Hsp110s, which are themselves members of the Hsp70 family. We report the structure of an Hsp110:Hsc70 nucleotide exchange complex. The complex is characterized by extensive protein:protein interactions and symmetric bridging interactions between the nucleotides bound in each partner protein's NBD. An electropositive pore allows nucleotides to enter and exit the complex. The role of nucleotides in complex formation and dissociation, and the effects of …

The Eagleville Times,Volume 6, Issue 14, Debbie Ryan

Eagleville Times

No abstract provided.

Programmed Death 1 Ligand Signaling Regulates The Generation Of Adaptive Foxp3+Cd4+ Regulatory T Cells, Li Wang, Kirina Pino-Lagos, Victor C. De Vries, Indira Guleria, Mohamed H. Sayegh, Randolph J. Noelle

Dartmouth Scholarship

Although mature dendritic cells (DCs) are potent initiators of adaptive immune response, immature steady-state DCs contribute to immune tolerance. In this study, we show that ex vivo splenic DCs are capable of inducing conversion of naïve CD4(+) T cells to adaptive Foxp3(+)CD4(+) regulatory T cells (aTreg) in the presence of TGF-beta. In particular, when compared with splenic CD8alpha(-) DCs, the CD8alpha(+) DC subset were superior in inducing higher frequencies of conversion. This was not attributable to the difference in basal level of costimulation, because deficiency of CD40 or CD80/86 signaling did not diminish the differential induction of Foxp3. Conversion was …

Sumoylation Regulates Lamin A Function And Is Lost In Lamin A Mutants Associated With Familial Cardiomyopathies, Yu-Qian Zhang, Kevin D. Sarge

Molecular and Cellular Biochemistry Faculty Publications

Lamin A mutations cause many diseases, including cardiomyopathies and Progeria Syndrome. The covalent attachment of small ubiquitin-like modifier (SUMO) polypeptides regulates the function of many proteins. Until now, no examples of human disease-causing mutations that occur within a sumoylation consensus sequence and alter sumoylation were known. We show that lamin A is sumoylated at lysine 201 and that two lamin A mutants associated with familial dilated cardiomyopathy, E203G and E203K, exhibit decreased sumoylation. E203 occupies the conserved +2 position in the sumoylation consensus Psi KXE. Lamin A mutants E203G, E203K, and K201R all exhibit a similar aberrant subcellular localization and …

A Novel Application Of Quantile Regression For Identification Of Biomarkers Exemplified By Equine Cartilage Microarray Data, Liping Huang, Wenying Zhu, Christopher P. Saunders, James N. Macleod, Mai Zhou, Arnold J. Stromberg, Arne C. Bathke

Veterinary Science Faculty Publications

BACKGROUND: Identification of biomarkers among thousands of genes arrayed for disease classification has been the subject of considerable research in recent years. These studies have focused on disease classification, comparing experimental groups of effected to normal patients. Related experiments can be done to identify tissue-restricted biomarkers, genes with a high level of expression in one tissue compared to other tissue types in the body.

RESULTS: In this study, cartilage was compared with ten other body tissues using a two color array experimental design. Thirty-seven probe sets were identified as cartilage biomarkers. Of these, 13 (35%) have existing annotation associated with …

Effects Of Early Gestation Gh Administration On Placental And Fetal Development In Sheep., Casey D Wright, Ryan J Orbus, Timothy Regnault, Russell V Anthony

Paediatrics Publications

Ovine GH (oGH) is synthesized in placental tissue during maximal placental growth and development. Our objectives were to localize oGH mRNA in the placenta, and study the impact of exogenous GH on twin pregnancies during the normal window (35-55 days of gestational age; dGA) of placental expression. In situ hybridization localized oGH mRNA in uterine luminal epithelium but not in tissues of fetal origin. While maternal GH and IGF-I concentrations were increased (P

Brain Fiber Tract Plasticity In Experimental Spinal Cord Injury: Diffusion Tensor Imaging, Jaivijay Ramu, Juan Herrera, Raymond Grill, Tobias Bockhorst, Ponnada Narayana

Faculty, Staff and Student Publications

Diffusion tensor imaging (DTI) and immunohistochemistry were performed in spinal cord injured rats to understand the basis for activation of multiple regions in the brain observed in functional magnetic resonance imaging (fMRI) studies. The measured fractional anisotropy (FA), a scalar measure of diffusion anisotropy, along the region encompassing corticospinal tracts (CST) indicates significant differences between control and injured groups in the 3 to 4 mm area posterior to bregma that correspond to internal capsule and cerebral peduncle. Additionally, DTI-based tractography in injured animals showed increased number of fibers that extend towards the cortex terminating in the regions that were activated …

Water-Soluble Fullerene (C60) Derivatives As Nonviral Gene-Delivery Vectors, Balaji Sitharaman, Tatiana Y Zakharian, Anita Saraf, Preeti Misra, Jared Ashcroft, Su Pan, Quynh P Pham, Antonios G Mikos, Lon J Wilson, David A Engler

Faculty, Staff and Student Publications

A new class of water-soluble C60 transfecting agents has been prepared using Hirsch-Bingel chemistry and assessed for their ability to act as gene-delivery vectors in vitro. In an effort to elucidate the relationship between the hydrophobicity of the fullerene core, the hydrophilicity of the water-solubilizing groups, and the overall charge state of the C60 vectors in gene delivery and expression, several different C60 derivatives were synthesized to yield either positively charged, negatively charged, or neutral chemical functionalities under physiological conditions. These fullerene derivatives were then tested for their ability to transfect cells grown in culture with DNA carrying the green …

Synaptotagmin-2 Controls Regulated Exocytosis But Not Other Secretory Responses Of Mast Cells*, Qun-Fang Wan, Alejandro Vila, Zhen-Yu Zhou, Ruth Heidelberger

Faculty, Staff and Student Publications

To better understand synaptic signaling at the mammalian rod bipolar cell terminal and pave the way for applying genetic approaches to the study of visual information processing in the mammalian retina, synaptic vesicle dynamics and intraterminal calcium were monitored in terminals of acutely isolated mouse rod bipolar cells and the number of ribbon-style active zones quantified. We identified a releasable pool, corresponding to a maximum of 7 s. The presence of a smaller, rapidly releasing pool and a small, fast component of refilling was also suggested. Following calcium channel closure, membrane surface area was restored to baseline with a time …