Article
Biochemistry & Molecular Biology
Chris S. Mesnard, Cody L. Barta, Asia L. Sladek, David Zenisek, Wallace B. Thoreson
Summary: The release of glutamate from rod and cone photoreceptor cells is facilitated by presynaptic ribbons composed mainly of the protein RIBEYE. The absence of ribbons in these cells leads to reduced temporal resolution, contrast sensitivity, and b-waves. The readily releasable pool of vesicles and the speed of vesicle replenishment are also reduced in cells lacking ribbons. Our findings suggest that synaptic ribbons play a crucial role in enhancing the release of vesicles and maintaining proper visual responses.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Multidisciplinary Sciences
Brent K. Young, Charu Ramakrishnan, Tushar Ganjawala, Ping Wang, Karl Deisseroth, Ning Tian
Summary: Neurons in the CNS have distinct characteristics based on neurotransmitter types, synaptic connections, morphology, and genetic profiles. A previously unidentified interneuron in the mammalian retina exhibits similarities with bipolar cells and amacrine cells, suggesting a potentially unique role in vision processing. This discovery highlights the complexity and diversity of neuronal populations in the CNS.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Multidisciplinary Sciences
Khang T. Huynh, Sarah Walters, Emma K. Foley, Jennifer J. Hunter
Summary: In the retina, molecules involved in metabolism and visual cycle exhibit intrinsic fluorescence that can be utilized to understand functional differences and disease conditions. Phasor analysis, an alternate method to traditional fitting, improves the evaluation and segregation of photoreceptor data in the retina. This analysis allows for the tracking of functional changes and provides insight into normal and diseased conditions at the cellular level.
SCIENTIFIC REPORTS
(2023)
Article
Biology
Duygu Karademir, Vyara Todorova, Lynn J. A. Ebner, Marijana Samardzija, Christian Grimm
Summary: This study utilizes droplet-based single-cell RNA sequencing to investigate the degeneration process in rod and cone photoreceptor cells in an RP mouse model. The results identify early changes in rods and potential early responses in cones, suggesting mechanisms involved in secondary cone degeneration. Furthermore, the study implicates EGR1 as a potential key regulator of early degenerative events in both types of photoreceptor cells.
Article
Ophthalmology
Rait Parmann, Vivienne C. Greenstein, Stephen H. Tsang, Janet R. Sparrow
Summary: This study evaluated scotopic sensitivity and outer retinal structure in choroideremia carriers using dark adapted chromatic perimetry and multi-modal imaging. The results showed comparable scotopic sensitivity in carriers' macular and peripheral areas compared to control group, but significantly decreased sensitivity in the peripapillary area where retinal structure changes were most severe.
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
(2022)
Article
Ophthalmology
Thomas Glonek, Tamara Snogren, Susan Y. Schmidt, Stacey L. Hearn, Majd A. Isreb, Jack Greiner
Summary: This study investigates the effects of illumination on retinal phosphatic metabolites in rats, finding that while ATP concentrations remain stable, GTP and creatine phosphate levels increase with light exposure. The research provides baseline measurements for retinal phosphatic metabolites and validates the chromatographic and spectroscopic methods used for studying retinal metabolism, showing a strong correlation between HPLC and P-31 NMR measurements.
EXPERIMENTAL EYE RESEARCH
(2022)
Review
Physiology
Rick H. Cote
Summary: This review article discusses the role of cGMP in the visual signaling pathway of the vertebrate retina, particularly focusing on the metabolism of cGMP in rod and cone photoreceptors. It highlights recent advances in understanding the structural and conformational changes involved in the activation of PDE6 by transducin and the regulation of its lifetime, as well as the potential therapeutic applications of pharmacological compounds targeting PDE6 in inherited retinal diseases.
PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY
(2021)
Article
Ophthalmology
C. S. Mesnard, C. L. Hays, C. L. Barta, A. L. Sladek, J. J. Grassmeyer, K. K. Hinz, R. M. Quadros, C. B. Gurumurthy, W. B. Thoreson
Summary: This study found that Syt7 is present in mouse rod terminals and contributes to release evoked by long depolarizing steps. Additionally, it was found that Syt1 is the principal sensor shaping rod and cone inputs to bipolar cells in response to light flashes.
EXPERIMENTAL EYE RESEARCH
(2022)
Article
Multidisciplinary Sciences
Yukari Takeda, Kazuma Sato, Yukari Hosoki, Shuji Tachibanaki, Chieko Koike, Akira Amano
Summary: This study investigates the divergent regulation of photoresponses in rods and cones. A detailed mathematical model based on the Hamer model was developed to analyze the differences in light sensitivity and desensitization between the two types of photoreceptor cells. The model successfully reconstructed the changes in concentrations of phosphorylated visual pigments, activated transducins, and phosphodiesterases in response to light intensity, ATP, and GTP.
SCIENTIFIC REPORTS
(2022)
Article
Ophthalmology
Mirella Telles Salgueiro Barboni, Sarah Leonardo Dias, Leonardo Aparecido Silva, Francisco Max Damico, Kallene Summer Vidal, Marcelo Fernandes Costa, Balazs Vince Nagy, Jan Kremers, Dora Fix Ventura
Summary: The study aimed to characterize changes in ERG and visual thresholds in DMD patients, showing that Dp260 is particularly required for normal rod-system function in dark adaptation.
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
(2021)
Article
Ophthalmology
Shumet T. Gegnaw, Cristina Sandu, Jorge Mendoza, Arthur A. Bergen, Marie-Paule Felder-Schmittbuhl
Summary: The retinal circadian system, consisting of clocks in different retinal cell types, regulates rhythmic processes in the retina. Studies on mice with rod-specific knockout of Bmal1 show that the circadian clock in rods plays a crucial role in regulating visual processing in a cell autonomous manner. This study suggests that the clock in rods influences visual function by modulating retinal responses to light stimuli.
EXPERIMENTAL EYE RESEARCH
(2021)
Article
Neurosciences
Darya A. Nikolaeva, Maria A. Nekrasova, Alexander Yu. Rotov, Luba A. Astakhova
Summary: Visual rods and cones in vertebrates have the ability to adapt to a wide range of ambient illumination through light adaptation mechanisms. Previous studies have established three calcium-sensitive feedback loops in both rods and cones. New evidence suggests that the molecular mechanisms of light adaptation may be more complex. This study focuses on a novel phenomenon called "adaptation memory" in rods and cones, where the recovery of light sensitivity takes seconds and the sensitivity remains decreased for minutes. The nature of this phenomenon differs between rods and cones, with the former being associated with long-lasting modifications of the phototransduction cascade and the latter being caused by bleaching of the visual pigment.
FRONTIERS IN MOLECULAR NEUROSCIENCE
(2023)
Article
Cell Biology
Sara K. Mayer, Jacintha Thomas, Megan Helms, Aishwarya Kothapalli, Ioana Cherascu, Adisa Salesevic, Elliot Stalter, Kai Wang, Poppy Datta, Charles Searby, Seongjin Seo, Ying Hsu, Sajag Bhattarai, Val C. Sheffield, Arlene V. Drack
Summary: Bardet-Biedl syndrome (BBS) is a genetic disorder caused by mutations in multiple genes, leading to early-onset retinal degeneration. This study phenotyped Bbs10 mice and identified a progressive degeneration of the outer nuclear layer, providing endpoints for preclinical trials.
DISEASE MODELS & MECHANISMS
(2022)
Article
Materials Science, Ceramics
J. K. Radhakrishnan, M. Kumara, Geetika
Summary: The study reveals that microwave power has a direct impact on the characteristics of ZnO nanostructures, allowing for morphology changes by adjusting microwave power. The fast growth along the high energy polar faces of ZnO is the reason for the formation of one dimensional ZnO structures, while the formation of hollow ZnO rods is due to further etching/material removal from the tip of the rods under high microwave power conditions at long growth durations.
CERAMICS INTERNATIONAL
(2021)
Article
Biochemistry & Molecular Biology
Jiazhou He, Masamichi Yamamoto, Kenta Sumiyama, Yumi Konagaya, Kenta Terai, Michiyuki Matsuda, Shinya Sato
Summary: The study revealed the highly heterogeneous metabolic environment surrounding photoreceptor cells in the retina, with rods showing a stronger response to 2-DG compared to cones, and rods recovering their AMPK and ATP levels within 30 minutes after 2-DG cessation. This suggests that cones surrounded by highly glycolytic rods become less dependent on glycolysis upon glycolysis inhibition.
Article
Cell Biology
Che-Hsiung Liu, Murali K. Bollepalli, Samuel Long, Sabrina Asteriti, Julie Tan, Julie A. Brill, Roger C. Hardie
JOURNAL OF CELL SCIENCE
(2018)
Article
Neurosciences
Giuseppe Federighi, Sabrina Asteriti, Lorenzo Cangiano
JOURNAL OF COMPARATIVE NEUROLOGY
(2020)
Article
Biochemical Research Methods
Sabrina Asteriti, Valeria Ricci, Lorenzo Cangiano
JOURNAL OF NEUROSCIENCE METHODS
(2020)
Article
Biochemistry & Molecular Biology
Weidi Chen, Zeyu Shen, Sabrina Asteriti, Zijing Chen, Fei Ye, Ziling Sun, Jun Wan, Craig Montell, Roger C. Hardie, Wei Liu, Mingjie Zhang
Summary: A new calcium-dependent binding mode between calmodulin (CaM) and Drosophila TRP is discovered, with TRP tail containing two CaM binding sites and CaM showing lobe-specific binding to CBS1&2. Mutations in both CBS1 and CBS2 eliminated CaM binding in full-length TRP, but alternative mechanisms may govern the feedback on channel activity under physiological conditions. Additionally, the closest mammalian paralog of Drosophila TRP, TRPC4, adopts a similar CaM binding mode.
Review
Physiology
Lorenzo Cangiano, Sabrina Asteriti
Summary: This study explores the interactions between different photoreceptors in the vertebrate retina and their physiological effects on visual signal processing and perception. It discusses the impact of coupling on various aspects of vision, such as signal to noise ratio, spatial acuity, and color discrimination, emphasizing data from a range of vertebrate models. The study also highlights gaps in knowledge and unanswered questions in the field, pointing towards limited evidence of ancestral forms of photoreceptor coupling.
PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Lorenzo Cangiano, Sabrina Asteriti
Summary: Ex vivo electroretinography (ERG) technique allows continuous and simultaneous recordings of mouse retinas' scotopic a-waves for long durations in a minimal amount of medium. This method is crucial for drug screening and studying retinal diseases.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Biochemistry & Molecular Biology
Sabrina Asteriti, Valerio Marino, Anna Avesani, Amedeo Biasi, Giuditta Dal Cortivo, Lorenzo Cangiano, Daniele Dell'Orco
Summary: This study explored the possibility of modulating the phototransduction cascade in mouse rods using direct or liposome-mediated administration of a recombinant protein. The results showed that the exogenous protein was fully incorporated into the mouse retina and induced a disease-like electrophysiological phenotype in the presence of a specific mutation. These findings are important for the treatment of autosomal dominant genetic diseases.
CELLULAR AND MOLECULAR LIFE SCIENCES
(2023)
Article
Biochemistry & Molecular Biology
Charlotte Johanna Beelen, Sabrina Asteriti, Lorenzo Cangiano, Karl-Wilhelm Koch, Daniele Dell'Orco
Summary: This study presents a comprehensive biochemical model of phototransduction in mouse rods, accurately describing the rod impedance and enabling the interconversion of dim flash responses. The model reproduces experimental photoresponses and confirms recent findings in vertebrate phototransduction, including the requirement of dimeric activation of PDE6 by transducin and the role of recoverin-mediated Ca2+-feedback on rhodopsin kinase. Stochastic simulations also suggest the importance of transient complexes between dark rhodopsin and transducin in increasing the reproducibility of single photon responses.
COMPUTATIONAL AND STRUCTURAL BIOTECHNOLOGY JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Sabrina Asteriti, Lorenzo Cangiano
Meeting Abstract
Urology & Nephrology
L. Cangiano, G. Federighi
JOURNAL OF SEXUAL MEDICINE
(2019)