10
views
0
recommends
+1 Recommend
1 collections
    0
    shares

      Call for Papers: Sex and Gender in Neurodegenerative Diseases

      Submit here before September 30, 2024

      About Neurodegenerative Diseases: 3.0 Impact Factor I 4.3 CiteScore I 0.695 Scimago Journal & Country Rank (SJR)

      • Record: found
      • Abstract: found
      • Article: found

      The Neural Basis of Dim-Light Vision in Echolocating Bats

      research-article

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Echolocating bats evolved a sophisticated biosonar imaging system that allows for a life in dim-light habitats. However, especially for far-range operations such as homing, bats can support biosonar by vision. Large eyes and a retina that mainly consists of rods are assumed to be the optical adjustments that enable bats to use visual information at low light levels. In addition to optical mechanisms, many nocturnal animals evolved neural adaptations such as elongated integration times or enlarged spatial sampling areas to further increase the sensitivity of their visual system by temporal or spatial summation of visual information. The neural mechanisms that underlie the visual capabilities of echolocating bats have, however, so far not been investigated. To shed light on spatial and temporal response characteristics of visual neurons in an echolocating bat, Phyllostomus discolor, we recorded extracellular multiunit activity in the retino-recipient superficial layers of the superior colliculus (SC). We discovered that response latencies of these neurons were generally in the mammalian range, whereas neural spatial sampling areas were unusually large compared to those measured in the SC of other mammals. From this we suggest that echolocating bats likely use spatial but not temporal summation of visual input to improve visual performance under dim-light conditions. Furthermore, we hypothesize that bats compensate for the loss of visual spatial precision, which is a byproduct of spatial summation, by integration of spatial information provided by both the visual and the biosonar systems. Given that knowledge about neural adaptations to dim-light vision is mainly based on studies done in non-mammalian species, our novel data provide a valuable contribution to the field and demonstrate the suitability of echolocating bats as a nocturnal animal model to study the neurophysiological aspects of dim-light vision.

          Related collections

          Most cited references54

          • Record: found
          • Abstract: found
          • Article: not found

          Neural synchrony in brain disorders: relevance for cognitive dysfunctions and pathophysiology.

          Following the discovery of context-dependent synchronization of oscillatory neuronal responses in the visual system, novel methods of time series analysis have been developed for the examination of task- and performance-related oscillatory activity and its synchronization. Studies employing these advanced techniques revealed that synchronization of oscillatory responses in the beta- and gamma-band is involved in a variety of cognitive functions, such as perceptual grouping, attention-dependent stimulus selection, routing of signals across distributed cortical networks, sensory-motor integration, working memory, and perceptual awareness. Here, we review evidence that certain brain disorders, such as schizophrenia, epilepsy, autism, Alzheimer's disease, and Parkinson's are associated with abnormal neural synchronization. The data suggest close correlations between abnormalities in neuronal synchronization and cognitive dysfunctions, emphasizing the importance of temporal coordination. Thus, focused search for abnormalities in temporal patterning may be of considerable clinical relevance.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Seeing better at night: life style, eye design and the optimum strategy of spatial and temporal summation.

            Animals which need to see well at night generally have eyes with wide pupils. This optical strategy to improve photon capture may be improved neurally by summing the outputs of neighbouring visual channels (spatial summation) or by increasing the length of time a sample of photons is counted by the eye (temporal summation). These summation strategies only come at the cost of spatial and temporal resolution. A simple analytical model is developed to investigate whether the improved photon catch afforded by summation really improves vision in dim light, or whether the losses in resolution actually make vision worse. The model, developed for both vertebrate camera eyes and arthropod compound eyes, calculates the finest spatial detail perceivable by a given eye design at a specified light intensity and image velocity. Visual performance is calculated for the apposition compound eye of the locust, the superposition compound eye of the dung beetle and the camera eye of the nocturnal toad. The results reveal that spatial and temporal summation is extremely beneficial to vision in dim light, especially in small eyes (e.g. compound eyes), which have a restricted ability to collect photons optically. The model predicts that using optimum spatiotemporal summation the locust can extend its vision to light intensities more than 100,000 times dimmer than if it relied on its optics alone. The relative amounts of spatial and temporal summation predicted to be optimal in dim light depend on the image velocity. Animals which are sedentary and rely on seeing small, slow images (such as the toad) are predicted to rely more on temporal summation and less on spatial summation. The opposite strategy is predicted for animals which need to see large, fast images. The predictions of the model agree very well with the known visual behaviours of nocturnal animals.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              The nocturnal bottleneck and the evolution of activity patterns in mammals.

              In 1942, Walls described the concept of a 'nocturnal bottleneck' in placental mammals, where these species could survive only by avoiding daytime activity during times in which dinosaurs were the dominant taxon. Walls based this concept of a longer episode of nocturnality in early eutherian mammals by comparing the visual systems of reptiles, birds and all three extant taxa of the mammalian lineage, namely the monotremes, marsupials (now included in the metatherians) and placentals (included in the eutherians). This review describes the status of what has become known as the nocturnal bottleneck hypothesis, giving an overview of the chronobiological patterns of activity. We review the ecological plausibility that the activity patterns of (early) eutherian mammals were restricted to the night, based on arguments relating to endothermia, energy balance, foraging and predation, taking into account recent palaeontological information. We also assess genes, relating to light detection (visual and non-visual systems) and the photolyase DNA protection system that were lost in the eutherian mammalian lineage. Our conclusion presently is that arguments in favour of the nocturnal bottleneck hypothesis in eutherians prevail.
                Bookmark

                Author and article information

                Journal
                BBE
                Brain Behav Evol
                10.1159/issn.0006-8977
                Brain, Behavior and Evolution
                S. Karger AG
                978-3-318-06671-5
                978-3-318-06672-2
                0006-8977
                1421-9743
                2019
                January 2020
                20 November 2019
                : 94
                : 1-4
                : 61-70
                Affiliations
                [_a] aChair of Zoology, Technische Universität München, Freising-Weihenstephan, Germany
                [_b] bMax Planck Institute for Ornithology, Department of Behavioural Neurobiology, Seewiesen, Germany
                Author notes
                *Dr. rer. nat. Susanne Hoffmann, Max Planck Institute for Ornithology, Department of Behavioural Neurobiology, Eberhard-Gwinner-Strasse 6a, DE–82319 Seewiesen (Germany), E-Mail shoffmann@orn.mpg.de
                Author information
                https://orcid.org/0000-0002-2767-6946
                Article
                504124 Brain Behav Evol 2019;94:61–70
                10.1159/000504124
                31747669
                68c240ba-9f1a-4a94-b055-ce4ab4400e2f
                © 2019 S. Karger AG, Basel

                Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher. Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug. Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

                History
                : 11 October 2019
                : 12 October 2019
                Page count
                Figures: 3, Pages: 10
                Categories
                Original Paper

                Geriatric medicine,Neurology,Cardiovascular Medicine,Neurosciences,Clinical Psychology & Psychiatry,Public health
                Microchiroptera,Superior colliculus,Response latency,Spatial receptive field,Contrast sensitivity

                Comments

                Comment on this article