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Cerio DG, Witmer LM. Orbital soft tissues, bones, and allometry: Implications for the size and position of crocodylian eyes. Anat Rec (Hoboken) 2023; 306:2537-2561. [PMID: 36508325 DOI: 10.1002/ar.25133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 09/14/2022] [Accepted: 10/25/2022] [Indexed: 12/14/2022]
Abstract
Although the visual system of crocodylians has attracted interest regarding optical parameters and retinal anatomy, fundamental questions remain about the allometry of the eyeball and whether such scaling is the same across all crown groups of crocodylians. In addition, anatomy and identities of adnexal soft tissues that interact with the visual system are not well understood in many cases. We used contrast-enhancing iodine stain and high-resolution micro-computed tomography to assess the anatomy of orbital soft tissues, including extraocular muscles and glands, in crocodylians. We also used regression analysis to estimate the allometric relationship between the bony orbit and eyeball across Alligator mississippiensis and Crocodylus niloticus for the first time. Results revealed tight, negatively allometric relationships between the bony orbit and eyeball. Notably, the eyes of C. niloticus were larger for a given orbit size than the eyes of A. mississippiensis, although the slope of the relationship was no different between these two crown crocodylian groups. Among the findings from our anatomical study, new details were uncovered about the homologies of muscles of the abducens complex. In particular, M. rectus lateralis of crocodylians is revealed to have a more complex form than previously appreciated, being adhered to the tendon of the nictitating membrane, which may be apomorphic for Crocodylia. Our calculation of the orbit-eyeball allometric relationship and study of the adnexal soft tissues of the crocodylian visual system, in combination with previous work by other teams in other crown saurian clades, is a critical, formerly missing, piece in the Extant Phylogenetic Bracket for restoring the visual apparatus of extinct crocodyliforms and other archosauriform groups.
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Affiliation(s)
- Donald Greene Cerio
- Department of Biological Sciences, Ohio University, Athens, Ohio, USA
- Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, Athens, Ohio, USA
- Ohio Center for Ecology and Evolutionary Studies, Ohio University, Athens, Ohio, USA
| | - Lawrence M Witmer
- Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, Athens, Ohio, USA
- Ohio Center for Ecology and Evolutionary Studies, Ohio University, Athens, Ohio, USA
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Marchese NA, Ríos MN, Guido ME. Müller glial cell photosensitivity: a novel function bringing higher complexity to vertebrate retinal physiology. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2023. [DOI: 10.1016/j.jpap.2023.100162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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Vee S, Barclay G, Lents NH. The glow of the night: The tapetum lucidum as a co-adaptation for the inverted retina. Bioessays 2022; 44:e2200003. [PMID: 36028472 DOI: 10.1002/bies.202200003] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 08/11/2022] [Accepted: 08/14/2022] [Indexed: 11/07/2022]
Abstract
The vertebrate retina is said to be inverted because the photoreceptors are oriented in the posterior direction and are thus unable to maximize photodetection under conditions of low illumination. The tapetum lucidum is a photoreflective structure located posterior to the photoreceptors in the eyes of some fish and terrestrial animals. The tapetum reflects light forward, giving incident photons a "second chance" to collide with a photoreceptor, substantially enhancing retinal photosensitivity in dim light. Across vertebrates (and arthropods), there are a wide variety of tapeta that vary in structure, chemical composition, and even tissue architecture, indicating repeated convergent evolution. To date, the tapetum has not been observed in any cephalopod, however, which also possess a camera-like eye, but with the retinal photoreceptors oriented in the anterior direction. We therefore hypothesize that the tapetum lucidum is a compensatory adaptation for the suboptimal design of the inverted retina of vertebrates.
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Affiliation(s)
- Samantha Vee
- Department of Ecology and Evolution, Stony Book University, The State University of New York, Stony Brook, New York, USA
| | - Gerald Barclay
- Department of Life Sciences, Highline College, Des Moines, Washington, USA
| | - Nathan H Lents
- Department of Sciences, John Jay College, The City University of New York, New York, New York, USA
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Abstract
The retina was historically considered as an “approachable part of the brain”; advantageous, for its simplicity, to use as a model organ for deciphering cellular and molecular mechanisms underlying physiology and pathology of the nervous system. However, the most relevant discoveries arise precisely from unveiling the complexity of the retina. A complexity that partially relies on the layered organization of an extended variety of specialized neuronal and glial cellular types and subtypes. Based on functional, morphological or transcriptome data, over 40 subtypes of retinal ganglion cells or 60 subtypes of retinal amacrine cells have been described. A high degree of specialization, that may lead to segregation into functionally diverse subtypes, is also conceivable for Müller cells, a pleiotropic glial component of all vertebrate retinas. The essential role of Müller glia in retinal homeostasis maintenance involves participation in structural, metabolic and intercellular communication processes. Additionally, they are the only retinal cells that possess regenerative potential in response to injury or disease, and thus may be considered as therapeutic tools. In the assumption that functional heterogeneity might be driven by molecular heterogeneity this review aims to compile emerging evidence that could broaden our understanding of Müller cell biology and retinal physiology. Summary statement Müller glial cells exert multiple essential functions in retinal physiology and retinopathies reflecting perhaps the existence of distinct Müller cellular subpopulations. Harnessing Müller cell heterogeneity may serve to enhance new therapeutic approaches for retinal disease.
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Affiliation(s)
- Monica Lamas
- Departamento de Farmacobiología. CINVESTAV-Sede Sur. México D.F. México
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Foveal shape, ultrastructure and photoreceptor composition in yellow-legged gull, Larus michahellis (Naumann, 1840). ZOOMORPHOLOGY 2021. [DOI: 10.1007/s00435-020-00512-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Sultan AE, Ghoneim AM, El-Gammal HL, El-Bakary NER. Vision adaptation in the laughing dove (Streptopelia senegalensis, Linnaeus, 1766) inferred from structural, ultrastructural, and genetic characterization. J Comp Neurol 2020; 529:1830-1848. [PMID: 33094834 DOI: 10.1002/cne.25059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 10/12/2020] [Accepted: 10/19/2020] [Indexed: 11/06/2022]
Abstract
Neuroanatomy of the retina reflects adaptation and acclimation for dark and light conditions. Retinal cells and genes must be functionally adjusted to various environmental luminosities. Opsins are brilliant molecules to assess the adaptations at the genetic and phenotypic levels. Photic adaptations may reveal new mechanisms that enhance vision abilities. Through the investigation of histological, ultrastructural constituents of the whole retinal layers, and the sequencing of shortwave length sensitive opsin 1 (SWS1) of the laughing dove (Streptopelia senegalensis), the current study confirms the plasticity of the retina in response to the natural photic conditions. Retinal pigmented epithelium has plentiful melanosomes, signifying a highly adapted eye for maximum light perception and protection. Variously colored oil droplets signify high color vision ability. Stratified outer nuclear layer with many Müller cells suggests high sensitivity to dim conditions and high retinal regeneration. The penetration of outer limiting membrane by photoreceptor nuclei and Müller cell microvilli could minimize the light reflection. Oligodendrocytes establish thick myelination demanded for a keen visual acuity. A functional violet sensitive SWS1 with crucial Ser90 is presumed. Molecular phylogeny showed a secondary loss as color vision was shifted back from ultraviolet (UV) sensitivity to the ancestral avian violet sensitivity, thus improving visual resolution. However, SWS1 has some UV sensitive residues. These findings implicate not only spectral adaptations with high color vision ability and acuity but also photoinduced structural reorganizations. Further studies are needed to assess the secrets between photons and the structural genes.
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Affiliation(s)
- Aya E Sultan
- Zoology Department, Faculty of Science, Damietta University, Damietta, Egypt
| | - Ahmed M Ghoneim
- Zoology Department, Faculty of Science, Damietta University, Damietta, Egypt
| | - Hekmat L El-Gammal
- Zoology Department, Faculty of Science, Damietta University, Damietta, Egypt
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Zueva L, Golubeva T, Korneeva E, Resto O, Inyushin M, Khmelinskii I, Makarov V. Electron microscopy study of the central retinal fovea in Pied flycatcher: evidence of a mechanism of light energy transmission through the retina. Heliyon 2020; 6:e04146. [PMID: 32566783 PMCID: PMC7298408 DOI: 10.1016/j.heliyon.2020.e04146] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 05/11/2020] [Accepted: 06/02/2020] [Indexed: 11/29/2022] Open
Abstract
We present unique ultrastructural data on avian retinal cells. Presently and earlier (Zueva et al., 2016) we explored distribution of intermediate filaments (IFs) in retinal cells of the Pied flycatcher (Ficedula hypoleuca, Passeriformes, Aves) in the central foveolar zone. This retinal zone only contains single and double cone photoreceptors. Previously we found that continuous IFs span Müller cells (MC) lengthwise from the retinal inner limiting membrane (ILM) layer up to the outer limiting membrane (OLM) layer. Here we describe long cylindrical bundles of IFs (IFBs) inside the cone inner segments (CIS) adjoining the cone plasma membrane, with these IFBs following along the cone lengthwise, and surrounding the cone at equal spacing one from the other. Double cones form a combined unit, wherein they are separated by their respective plasma membranes. Double cones thus have a common external ring of IFBs, surrounding both cone components. In the layer of cilia, the IFBs that continue into the cone outer segment (COS) follow on to the cone apical tip along the direction of incident light, with single IFs separating from the IFB, touching, and sometimes passing in-between the light-sensitive lamellae of the COS. These new data support our previous hypothesis on the quantum mechanism of light energy propagation through the vertebrate retina (Zueva et al., 2016, 2019).
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Affiliation(s)
- Lidia Zueva
- University of Puerto Rico, Rio Piedras Campus, PO Box 23343, San Juan, PR 00931-3343, USA
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Thorez pr. 44, 194223, St-Petersburg, Russia
- Universidad Central del Caribe, Bayamón, PR 00960-6032, USA
| | - Tatiana Golubeva
- Department of Vertebrate Zoology, Lomonosov Moscow State University, 119992, Moscow, Russia
| | - Elena Korneeva
- Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Butlerova str., 5a, 117485, Moscow, Russia
| | - Oscar Resto
- University of Puerto Rico, Rio Piedras Campus, PO Box 23343, San Juan, PR 00931-3343, USA
| | | | - Igor Khmelinskii
- University of the Algarve, FCT, DQF and CEOT, 8005-139, Faro, Portugal
| | - Vladimir Makarov
- University of Puerto Rico, Rio Piedras Campus, PO Box 23343, San Juan, PR 00931-3343, USA
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Tissue Transparency In Vivo. Molecules 2019; 24:molecules24132388. [PMID: 31261621 PMCID: PMC6651221 DOI: 10.3390/molecules24132388] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 06/19/2019] [Accepted: 06/25/2019] [Indexed: 12/15/2022] Open
Abstract
In vivo tissue transparency in the visible light spectrum is beneficial for many research applications that use optical methods, whether it involves in vivo optical imaging of cells or their activity, or optical intervention to affect cells or their activity deep inside tissues, such as brain tissue. The classical view is that a tissue is transparent if it neither absorbs nor scatters light, and thus absorption and scattering are the key elements to be controlled to reach the necessary transparency. This review focuses on the latest genetic and chemical approaches for the decoloration of tissue pigments to reduce visible light absorption and the methods to reduce scattering in live tissues. We also discuss the possible molecules involved in transparency.
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