1
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Thomas JT, Huerlimann R, Schunter C, Watson SA, Munday PL, Ravasi T. Transcriptomic responses in the nervous system and correlated behavioural changes of a cephalopod exposed to ocean acidification. BMC Genomics 2024; 25:635. [PMID: 38918719 PMCID: PMC11202396 DOI: 10.1186/s12864-024-10542-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 06/20/2024] [Indexed: 06/27/2024] Open
Abstract
BACKGROUND The nervous system is central to coordinating behavioural responses to environmental change, likely including ocean acidification (OA). However, a clear understanding of neurobiological responses to OA is lacking, especially for marine invertebrates. RESULTS We evaluated the transcriptomic response of the central nervous system (CNS) and eyes of the two-toned pygmy squid (Idiosepius pygmaeus) to OA conditions, using a de novo transcriptome assembly created with long read PacBio ISO-sequencing data. We then correlated patterns of gene expression with CO2 treatment levels and OA-affected behaviours in the same individuals. OA induced transcriptomic responses within the nervous system related to various different types of neurotransmission, neuroplasticity, immune function and oxidative stress. These molecular changes may contribute to OA-induced behavioural changes, as suggested by correlations among gene expression profiles, CO2 treatment and OA-affected behaviours. CONCLUSIONS This study provides the first molecular insights into the neurobiological effects of OA on a cephalopod and correlates molecular changes with whole animal behavioural responses, helping to bridge the gaps in our knowledge between environmental change and animal responses.
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Affiliation(s)
- Jodi T Thomas
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia.
- Marine Climate Change Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan.
| | - Roger Huerlimann
- Marine Climate Change Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Celia Schunter
- Swire Institute of Marine Science, School of Biological Sciences, The University of Hong Kong, Pok Fu Lam Road, Hong Kong SAR, China
| | - Sue-Ann Watson
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia
- College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
- Biodiversity and Geosciences Program, Queensland Museum Tropics, Queensland Museum, Townsville, QLD, 4810, Australia
| | - Philip L Munday
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia
- College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia
| | - Timothy Ravasi
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia
- Marine Climate Change Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
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2
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Jiun-Shian Wu J, Chiao CC. Switching by cuttlefish of preying tactics targeted at moving prey. iScience 2023; 26:108122. [PMID: 37876802 PMCID: PMC10590972 DOI: 10.1016/j.isci.2023.108122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 07/31/2023] [Accepted: 09/29/2023] [Indexed: 10/26/2023] Open
Abstract
Previous studies have demonstrated that the size of the prey relative to the cuttlefish is important to the choice between tentacular strike and jump-on tactics. In the present study, we investigated the decision-making in the cuttlefish's tactical switch when preying on the same size prey. A servomotor system controlling the movement of a shrimp was used to elicit the cuttlefish's preying behavior. The success rate of prey capture and the kinematics of visual attack were examined systematically. The results showed that the jump-on behavior appeared mostly after a miss attack by previous tentacular strike on a moving shrimp. Compared with a visual attack with tentacles, the jump-on tactic has over a shorter attacking distance and wider attacking angles. Thus, these two different preying tactics have different operating ranges relative to the prey. More importantly, the cuttlefish can adjust their preying tactics adaptively depending on their prior preying experience.
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Affiliation(s)
- José Jiun-Shian Wu
- Institute of Systems Neuroscience, National Tsing Hua University, Hsinchu, Taiwan
- Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan
| | - Chuan-Chin Chiao
- Institute of Systems Neuroscience, National Tsing Hua University, Hsinchu, Taiwan
- Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan
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3
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Pungor JR, Niell CM. The neural basis of visual processing and behavior in cephalopods. Curr Biol 2023; 33:R1106-R1118. [PMID: 37875093 PMCID: PMC10664291 DOI: 10.1016/j.cub.2023.08.093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Abstract
Coleoid cephalopods (octopuses, squids and cuttlefishes) are the only branch of the animal kingdom outside of vertebrates to have evolved both a large brain and camera-type eyes. They are highly dependent on vision, with the majority of their brain devoted to visual processing. Their excellent vision supports a range of advanced visually guided behaviors, from navigation and prey capture, to the ability to camouflage based on their surroundings. However, their brain organization is radically different from that of vertebrates, as well as other invertebrates, providing a unique opportunity to explore how a novel neural architecture for vision is organized and functions. Relatively few studies have examined the cephalopod visual system using current neuroscience approaches, to the extent that there has not even been a measurement of single-cell receptive fields in their central visual system. Therefore, there remains a tremendous amount that is unknown about the neural basis of vision in these extraordinary animals. Here, we review the existing knowledge of the organization and function of the cephalopod visual system to provide a framework for examining the neural circuits and computational mechanisms mediating their remarkable visual capabilities.
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Affiliation(s)
- Judit R Pungor
- Department of Biology and Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Cristopher M Niell
- Department of Biology and Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA.
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4
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Klug C, Hoffmann R, Tischlinger H, Fuchs D, Pohle A, Rowe A, Rouget I, Kruta I. 'Arm brains' (axial nerves) of Jurassic coleoids and the evolution of coleoid neuroanatomy. SWISS JOURNAL OF PALAEONTOLOGY 2023; 142:22. [PMID: 37780806 PMCID: PMC10533608 DOI: 10.1186/s13358-023-00285-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 08/11/2023] [Indexed: 10/03/2023]
Abstract
Although patchy, the fossil record of coleoids bears a wealth of information on their soft part anatomy. Here, we describe remains of the axial nerve cord from both decabrachian (Acanthoteuthis, Belemnotheutis, Chondroteuthis) and octobrachian (Plesioteuthis, Proteroctopus, Vampyronassa) coleoids from the Jurassic. We discuss some hypotheses reflecting on possible evolutionary drivers behind the neuroanatomical differentiation of the coleoid arm crown. We also propose some hypotheses on potential links between habitat depth, mode of life and the evolution of the Coleoidea. Supplementary Information The online version contains supplementary material available at 10.1186/s13358-023-00285-3.
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Affiliation(s)
- Christian Klug
- Paläontologisches Institut und Museum, Universität Zürich, Karl-Schmid-Strasse 4, 8006 Zurich, Switzerland
| | - René Hoffmann
- Institute of Geology, Mineralogy, & Geophysics, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Helmut Tischlinger
- 85134 Stammham, Germany
- Jura-Museum Eichstätt, Willibaldsburg, 85072 Eichstätt, Germany
| | - Dirk Fuchs
- SNSB-Bayerische Staatssammlung für Paläontologie und Geologie, Richard-Wagner-Straße 10, 80333 Munich, Germany
| | - Alexander Pohle
- Paläontologisches Institut und Museum, Universität Zürich, Karl-Schmid-Strasse 4, 8006 Zurich, Switzerland
- Institute of Geology, Mineralogy, & Geophysics, Ruhr-Universität Bochum, 44801 Bochum, Germany
| | - Alison Rowe
- Centre de recherche en paléontologie - Paris, Sorbonne Université-MNHN-CNRS-CR2P, 4 Pl. Jussieu, 75005 Paris, France
| | - Isabelle Rouget
- Centre de recherche en paléontologie - Paris, Sorbonne Université-MNHN-CNRS-CR2P, 4 Pl. Jussieu, 75005 Paris, France
| | - Isabelle Kruta
- Centre de recherche en paléontologie - Paris, Sorbonne Université-MNHN-CNRS-CR2P, 4 Pl. Jussieu, 75005 Paris, France
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5
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Pungor JR, Allen VA, Songco-Casey JO, Niell CM. Functional organization of visual responses in the octopus optic lobe. Curr Biol 2023; 33:2784-2793.e3. [PMID: 37343556 PMCID: PMC11056276 DOI: 10.1016/j.cub.2023.05.069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/24/2023] [Accepted: 05/30/2023] [Indexed: 06/23/2023]
Abstract
Cephalopods are highly visual animals with camera-type eyes, large brains, and a rich repertoire of visually guided behaviors. However, the cephalopod brain evolved independently from those of other highly visual species, such as vertebrates; therefore, the neural circuits that process sensory information are profoundly different. It is largely unknown how their powerful but unique visual system functions, as there have been no direct neural measurements of visual responses in the cephalopod brain. In this study, we used two-photon calcium imaging to record visually evoked responses in the primary visual processing center of the octopus central brain, the optic lobe, to determine how basic features of the visual scene are represented and organized. We found spatially localized receptive fields for light (ON) and dark (OFF) stimuli, which were retinotopically organized across the optic lobe, demonstrating a hallmark of visual system organization shared across many species. An examination of these responses revealed transformations of the visual representation across the layers of the optic lobe, including the emergence of the OFF pathway and increased size selectivity. We also identified asymmetries in the spatial processing of ON and OFF stimuli, which suggest unique circuit mechanisms for form processing that may have evolved to suit the specific demands of processing an underwater visual scene. This study provides insight into the neural processing and functional organization of the octopus visual system, highlighting both shared and unique aspects, and lays a foundation for future studies of the neural circuits that mediate visual processing and behavior in cephalopods.
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Affiliation(s)
- Judit R Pungor
- Department of Biology and Institute of Neuroscience, University of Oregon, Eugene, OR 97405, USA.
| | - V Angelique Allen
- Department of Biology and Institute of Neuroscience, University of Oregon, Eugene, OR 97405, USA
| | - Jeremea O Songco-Casey
- Department of Biology and Institute of Neuroscience, University of Oregon, Eugene, OR 97405, USA
| | - Cristopher M Niell
- Department of Biology and Institute of Neuroscience, University of Oregon, Eugene, OR 97405, USA.
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6
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Pophale A, Shimizu K, Mano T, Iglesias TL, Martin K, Hiroi M, Asada K, Andaluz PG, Van Dinh TT, Meshulam L, Reiter S. Wake-like skin patterning and neural activity during octopus sleep. Nature 2023; 619:129-134. [PMID: 37380770 PMCID: PMC10322707 DOI: 10.1038/s41586-023-06203-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 05/11/2023] [Indexed: 06/30/2023]
Abstract
While sleeping, many vertebrate groups alternate between at least two sleep stages: rapid eye movement and slow wave sleep1-4, in part characterized by wake-like and synchronous brain activity, respectively. Here we delineate neural and behavioural correlates of two stages of sleep in octopuses, marine invertebrates that evolutionarily diverged from vertebrates roughly 550 million years ago (ref. 5) and have independently evolved large brains and behavioural sophistication. 'Quiet' sleep in octopuses is rhythmically interrupted by approximately 60-s bouts of pronounced body movements and rapid changes in skin patterning and texture6. We show that these bouts are homeostatically regulated, rapidly reversible and come with increased arousal threshold, representing a distinct 'active' sleep stage. Computational analysis of active sleep skin patterning reveals diverse dynamics through a set of patterns conserved across octopuses and strongly resembling those seen while awake. High-density electrophysiological recordings from the central brain reveal that the local field potential (LFP) activity during active sleep resembles that of waking. LFP activity differs across brain regions, with the strongest activity during active sleep seen in the superior frontal and vertical lobes, anatomically connected regions associated with learning and memory function7-10. During quiet sleep, these regions are relatively silent but generate LFP oscillations resembling mammalian sleep spindles11,12 in frequency and duration. The range of similarities with vertebrates indicates that aspects of two-stage sleep in octopuses may represent convergent features of complex cognition.
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Affiliation(s)
- Aditi Pophale
- Computational Neuroethology Unit, Okinawa Institute of Science and Technology (OIST) Graduate University, Okinawa, Japan
| | - Kazumichi Shimizu
- Computational Neuroethology Unit, Okinawa Institute of Science and Technology (OIST) Graduate University, Okinawa, Japan
| | - Tomoyuki Mano
- Computational Neuroethology Unit, Okinawa Institute of Science and Technology (OIST) Graduate University, Okinawa, Japan
| | - Teresa L Iglesias
- Marine Animal Research Support Team, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Kerry Martin
- Computational Neuroethology Unit, Okinawa Institute of Science and Technology (OIST) Graduate University, Okinawa, Japan
| | - Makoto Hiroi
- Computational Neuroethology Unit, Okinawa Institute of Science and Technology (OIST) Graduate University, Okinawa, Japan
| | - Keishu Asada
- Computational Neuroethology Unit, Okinawa Institute of Science and Technology (OIST) Graduate University, Okinawa, Japan
| | - Paulette García Andaluz
- Computational Neuroethology Unit, Okinawa Institute of Science and Technology (OIST) Graduate University, Okinawa, Japan
| | - Thi Thu Van Dinh
- Computational Neuroethology Unit, Okinawa Institute of Science and Technology (OIST) Graduate University, Okinawa, Japan
| | - Leenoy Meshulam
- Theoretical Sciences Visiting Program, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
- Computational Neuroscience Center, University of Washington, Seattle, WA, USA
| | - Sam Reiter
- Computational Neuroethology Unit, Okinawa Institute of Science and Technology (OIST) Graduate University, Okinawa, Japan.
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7
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Imperadore P, Cagnin S, Allegretti V, Millino C, Raffini F, Fiorito G, Ponte G. Transcriptome-wide selection and validation of a solid set of reference genes for gene expression studies in the cephalopod mollusk Octopus vulgaris. Front Mol Neurosci 2023; 16:1091305. [PMID: 37266373 PMCID: PMC10230085 DOI: 10.3389/fnmol.2023.1091305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 02/20/2023] [Indexed: 06/03/2023] Open
Abstract
Octopus vulgaris is a cephalopod mollusk and an active marine predator that has been at the center of a number of studies focused on the understanding of neural and biological plasticity. Studies on the machinery involved in e.g., learning and memory, regeneration, and neuromodulation are required to shed light on the conserved and/or unique mechanisms that these animals have evolved. Analysis of gene expression is one of the most essential means to expand our understanding of biological machinery, and the selection of an appropriate set of reference genes is the prerequisite for the quantitative real-time polymerase chain reaction (qRT-PCR). Here we selected 77 candidate reference genes (RGs) from a pool of stable and relatively high-expressed transcripts identified from the full-length transcriptome of O. vulgaris, and we evaluated their expression stabilities in different tissues through geNorm, NormFinder, Bestkeeper, Delta-CT method, and RefFinder. Although various algorithms provided different assemblages of the most stable reference genes for the different kinds of tissues tested here, a comprehensive ranking revealed RGs specific to the nervous system (Ov-RNF7 and Ov-RIOK2) and Ov-EIF2A and Ov-CUL1 across all considered tissues. Furthermore, we validated RGs by assessing the expression profiles of nine target genes (Ov-Naa15, Ov-Ltv1, Ov-CG9286, Ov-EIF3M, Ov-NOB1, Ov-CSDE1, Ov-Abi2, Ov-Homer2, and Ov-Snx20) in different areas of the octopus nervous system (gastric ganglion, as control). Our study allowed us to identify the most extensive set of stable reference genes currently available for the nervous system and appendages of adult O. vulgaris.
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Affiliation(s)
- Pamela Imperadore
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - Stefano Cagnin
- Department of Biology, University of Padova, Padova, Italy
- CIR-Myo Myology Center, University of Padova, Padova, Italy
| | - Vittoria Allegretti
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy
| | | | - Francesca Raffini
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - Graziano Fiorito
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy
| | - Giovanna Ponte
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Napoli, Italy
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8
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Flash T, Zullo L. Biomechanics, motor control and dynamic models of the soft limbs of the octopus and other cephalopods. J Exp Biol 2023; 226:307147. [PMID: 37083140 DOI: 10.1242/jeb.245295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
Muscular hydrostats are organs composed entirely of packed arrays of incompressible muscles and lacking any skeletal support. Found in both vertebrates and invertebrates, they are of great interest for comparative biomechanics from engineering and evolutionary perspectives. The arms of cephalopods (e.g. octopus and squid) are particularly interesting muscular hydrostats because of their flexibility and ability to generate complex behaviors exploiting elaborate nervous systems. Several lines of evidence from octopus studies point to the use of both brain and arm-embedded motor control strategies that have evolved to simplify the complexities associated with the control of flexible and hyper-redundant limbs and bodies. Here, we review earlier and more recent experimental studies on octopus arm biomechanics and neural motor control. We review several dynamic models used to predict the kinematic characteristics of several basic motion primitives, noting the shortcomings of the current models in accounting for behavioral observations. We also discuss the significance of impedance (stiffness and viscosity) in controlling the octopus's motor behavior. These factors are considered in light of several new models of muscle biomechanics that could be used in future research to gain a better understanding of motor control in the octopus. There is also a need for updated models that encompass stiffness and viscosity for designing and controlling soft robotic arms. The field of soft robotics has boomed over the past 15 years and would benefit significantly from further progress in biomechanical and motor control studies on octopus and other muscular hydrostats.
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Affiliation(s)
- Tamar Flash
- Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Letizia Zullo
- Bioinspired Soft Robotics & Center for Synaptic Neuroscience and Technology (NSYN), Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
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9
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Pungor JR, Allen VA, Songco-Casey JO, Niell CM. Functional organization of visual responses in the octopus optic lobe. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.16.528734. [PMID: 36824726 PMCID: PMC9949128 DOI: 10.1101/2023.02.16.528734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Cephalopods are highly visual animals with camera-type eyes, large brains, and a rich repertoire of visually guided behaviors. However, the cephalopod brain evolved independently from that of other highly visual species, such as vertebrates, and therefore the neural circuits that process sensory information are profoundly different. It is largely unknown how their powerful but unique visual system functions, since there have been no direct neural measurements of visual responses in the cephalopod brain. In this study, we used two-photon calcium imaging to record visually evoked responses in the primary visual processing center of the octopus central brain, the optic lobe, to determine how basic features of the visual scene are represented and organized. We found spatially localized receptive fields for light (ON) and dark (OFF) stimuli, which were retinotopically organized across the optic lobe, demonstrating a hallmark of visual system organization shared across many species. Examination of these responses revealed transformations of the visual representation across the layers of the optic lobe, including the emergence of the OFF pathway and increased size selectivity. We also identified asymmetries in the spatial processing of ON and OFF stimuli, which suggest unique circuit mechanisms for form processing that may have evolved to suit the specific demands of processing an underwater visual scene. This study provides insight into the neural processing and functional organization of the octopus visual system, highlighting both shared and unique aspects, and lays a foundation for future studies of the neural circuits that mediate visual processing and behavior in cephalopods. Highlights The functional organization and visual response properties of the cephalopod visual system are largely unknownUsing calcium imaging, we performed mapping of visual responses in the octopus optic lobeVisual responses demonstrate localized ON and OFF receptive fields with retinotopic organizationON/OFF pathways and size selectivity emerge across layers of the optic lobe and have distinct properties relative to other species.
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Affiliation(s)
- Judit R Pungor
- Department of Biology and Institute of Neuroscience, University of Oregon, Eugene OR 97405
| | - V Angelique Allen
- Department of Biology and Institute of Neuroscience, University of Oregon, Eugene OR 97405
| | - Jeremea O Songco-Casey
- Department of Biology and Institute of Neuroscience, University of Oregon, Eugene OR 97405
| | - Cristopher M Niell
- Department of Biology and Institute of Neuroscience, University of Oregon, Eugene OR 97405
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10
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Gutnick T, Neef A, Cherninskyi A, Ziadi-Künzli F, Di Cosmo A, Lipp HP, Kuba MJ. Recording electrical activity from the brain of behaving octopus. Curr Biol 2023; 33:1171-1178.e4. [PMID: 36827988 DOI: 10.1016/j.cub.2023.02.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/25/2023] [Accepted: 02/01/2023] [Indexed: 02/25/2023]
Abstract
Octopuses, which are among the most intelligent invertebrates,1,2,3,4 have no skeleton and eight flexible arms whose sensory and motor activities are at once autonomous and coordinated by a complex central nervous system.5,6,7,8 The octopus brain contains a very large number of neurons, organized into numerous distinct lobes, the functions of which have been proposed based largely on the results of lesioning experiments.9,10,11,12,13 In other species, linking brain activity to behavior is done by implanting electrodes and directly correlating electrical activity with observed animal behavior. However, because the octopus lacks any hard structure to which recording equipment can be anchored, and because it uses its eight flexible arms to remove any foreign object attached to the outside of its body, in vivo recording of electrical activity from untethered, behaving octopuses has thus far not been possible. Here, we describe a novel technique for inserting a portable data logger into the octopus and implanting electrodes into the vertical lobe system, such that brain activity can be recorded for up to 12 h from unanesthetized, untethered octopuses and can be synchronized with simultaneous video recordings of behavior. In the brain activity, we identified several distinct patterns that appeared consistently in all animals. While some resemble activity patterns in mammalian neural tissue, others, such as episodes of 2 Hz, large amplitude oscillations, have not been reported. By providing an experimental platform for recording brain activity in behaving octopuses, our study is a critical step toward understanding how the brain controls behavior in these remarkable animals.
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Affiliation(s)
- Tamar Gutnick
- Okinawa Institute of Science and Technology, Graduate University, Physics and Biology Unit, 904 0495 Okinawa, Japan; Department of Biology, University of Naples Federico II, Via Cintia 26, 80126 Napoli, Italy.
| | - Andreas Neef
- Göttingen Campus Institute for Dynamics of Biological Networks, 37073 Göttingen, Germany; Max Planck Institute for Dynamics and Self-Organization, 37077 Göttingen, Germany; Bernstein Center for Computational Neuroscience, 37073 Göttingen, Germany; Institute for the Dynamics of Complex Systems, University of Göttingen, 37075 Göttingen, Germany; Max Planck Institute for Multidisciplinary Sciences, 37075 Göttingen, Germany; Center for Biostructural Imaging of Neurodegeneration, 37075 Göttingen, Germany
| | | | - Fabienne Ziadi-Künzli
- Okinawa Institute of Science and Technology, Graduate University, Nonlinear and Non-equilibrium Physics Unit, Okinawa 904-0495, Japan
| | - Anna Di Cosmo
- Department of Biology, University of Naples Federico II, Via Cintia 26, 80126 Napoli, Italy
| | - Hans-Peter Lipp
- Institute of Evolutionary Medicine, Faculty of Medicine, University of Zurich, 8057 Zurich, Switzerland
| | - Michael J Kuba
- Okinawa Institute of Science and Technology, Graduate University, Physics and Biology Unit, 904 0495 Okinawa, Japan; Department of Biology, University of Naples Federico II, Via Cintia 26, 80126 Napoli, Italy
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11
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Chung WS, López-Galán A, Kurniawan ND, Marshall NJ. The brain structure and the neural network features of the diurnal cuttlefish Sepia plangon. iScience 2023; 26:105846. [PMID: 36624840 PMCID: PMC9823234 DOI: 10.1016/j.isci.2022.105846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 12/02/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022] Open
Abstract
Cuttlefish are known for their rapid changes of appearance enabling camouflage and con-specific communication for mating or agonistic display. However, interpretation of their sophisticated behaviors and responsible brain areas is based on the better-studied squid brain atlas. Here we present the first detailed description of the neuroanatomical features of a tropical and diurnal cuttlefish, Sepia plangon, coupled with observations on ontogenetic changes in its visual and learning centers using a suite of MRI-based techniques and histology. We then make comparisons to a loliginid squid, treating it as a 'baseline', and also to other cuttlefish species to help construct a connectivity map of the cuttlefish brain. Differences in brain anatomy and the previously unknown neural connections associated with camouflage, motor control and chemosensory function are described. These findings link brain heterogeneity to ecological niches and lifestyle, feeding hypotheses and evolutionary history, and provide a timely, new technology update to older literature.
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Affiliation(s)
- Wen-Sung Chung
- Queensland Brain Institute, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Alejandra López-Galán
- Queensland Brain Institute, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Nyoman D. Kurniawan
- Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD 4072, Australia
| | - N. Justin Marshall
- Queensland Brain Institute, The University of Queensland, St Lucia, QLD 4072, Australia
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12
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Jiang D, Liu Q, Sun J, Liu S, Fan G, Wang L, Zhang Y, Seim I, An S, Liu X, Li Q, Zheng X. The gold-ringed octopus (Amphioctopus fangsiao) genome and cerebral single-nucleus transcriptomes provide insights into the evolution of karyotype and neural novelties. BMC Biol 2022; 20:289. [PMID: 36575497 PMCID: PMC9795677 DOI: 10.1186/s12915-022-01500-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 12/08/2022] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Coleoid cephalopods have distinctive neural and morphological characteristics compared to other invertebrates. Early studies reported massive genomic rearrangements occurred before the split of octopus and squid lineages (Proc Natl Acad Sci U S A 116:3030-5, 2019), which might be related to the neural innovations of their brain, yet the details remain elusive. Here we combine genomic and single-nucleus transcriptome analyses to investigate the octopod chromosome evolution and cerebral characteristics. RESULTS We present a chromosome-level genome assembly of a gold-ringed octopus, Amphioctopus fangsiao, and a single-nucleus transcriptome of its supra-esophageal brain. Chromosome-level synteny analyses estimate that the chromosomes of the ancestral octopods experienced multiple chromosome fission/fusion and loss/gain events by comparing with the nautilus genome as outgroup, and that a conserved genome organization was detected during the evolutionary process from the last common octopod ancestor to their descendants. Besides, protocadherin, GPCR, and C2H2 ZNF genes are thought to be highly related to the neural innovations in cephalopods (Nature 524:220-4, 2015), and the chromosome analyses pinpointed several collinear modes of these genes on the octopod chromosomes, such as the collinearity between PCDH and C2H2 ZNF, as well as between GPCR and C2H2 ZNF. Phylogenetic analyses show that the expansion of the octopod protocadherin genes is driven by a tandem-duplication mechanism on one single chromosome, including two separate expansions at 65 million years ago (Ma) and 8-14 Ma, respectively. Furthermore, we identify eight cell types (i.e., cholinergic and glutamatergic neurons) in the supra-esophageal brain of A. fangsiao, and the single-cell expression analyses reveal the co-expression of protocadherin and GPCR in specific neural cells, which may contribute to the neural development and signal transductions in the octopod brain. CONCLUSIONS The octopod genome analyses reveal the dynamic evolutionary history of octopod chromosomes and neural-related gene families. The single-nucleus transcriptomes of the supra-esophageal brain indicate their cellular heterogeneities and functional interactions with other tissues (i.e., gill), which provides a foundation for further octopod cerebral studies.
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Affiliation(s)
- Dianhang Jiang
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Ocean University of China, Qingdao, 266003, China
- Institute of Evolution & Marine Biodiversity (IEMB), Qingdao, 266003, China
| | - Qun Liu
- BGI-QingDao, BGI-Shenzhen, Qingdao, 266555, China
| | - Jin Sun
- Institute of Evolution & Marine Biodiversity (IEMB), Qingdao, 266003, China
| | - Shikai Liu
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Ocean University of China, Qingdao, 266003, China
| | - Guangyi Fan
- BGI-QingDao, BGI-Shenzhen, Qingdao, 266555, China
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Lihua Wang
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Ocean University of China, Qingdao, 266003, China
- Institute of Evolution & Marine Biodiversity (IEMB), Qingdao, 266003, China
| | - Yaolei Zhang
- BGI-QingDao, BGI-Shenzhen, Qingdao, 266555, China
| | - Inge Seim
- Integrative Biology Laboratory, College of Life Sciences, Nanjing Normal University, Nanjing, 210046, China
- School of Biology and Environmental Science, Queensland University of Technology, Brisbane, 4000, Australia
| | - Shucai An
- The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Xin Liu
- BGI-QingDao, BGI-Shenzhen, Qingdao, 266555, China
| | - Qi Li
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Ocean University of China, Qingdao, 266003, China
| | - Xiaodong Zheng
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Ocean University of China, Qingdao, 266003, China.
- Institute of Evolution & Marine Biodiversity (IEMB), Qingdao, 266003, China.
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Zolotarov G, Fromm B, Legnini I, Ayoub S, Polese G, Maselli V, Chabot PJ, Vinther J, Styfhals R, Seuntjens E, Di Cosmo A, Peterson KJ, Rajewsky N. MicroRNAs are deeply linked to the emergence of the complex octopus brain. SCIENCE ADVANCES 2022; 8:eadd9938. [PMID: 36427315 PMCID: PMC9699675 DOI: 10.1126/sciadv.add9938] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 10/27/2022] [Indexed: 05/25/2023]
Abstract
Soft-bodied cephalopods such as octopuses are exceptionally intelligent invertebrates with a highly complex nervous system that evolved independently from vertebrates. Because of elevated RNA editing in their nervous tissues, we hypothesized that RNA regulation may play a major role in the cognitive success of this group. We thus profiled messenger RNAs and small RNAs in three cephalopod species including 18 tissues of the Octopus vulgaris. We show that the major RNA innovation of soft-bodied cephalopods is an expansion of the microRNA (miRNA) gene repertoire. These evolutionarily novel miRNAs were primarily expressed in adult neuronal tissues and during the development and had conserved and thus likely functional target sites. The only comparable miRNA expansions happened, notably, in vertebrates. Thus, we propose that miRNAs are intimately linked to the evolution of complex animal brains.
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Affiliation(s)
- Grygoriy Zolotarov
- Laboratory of Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Hannoversche Str 28, 10115 Berlin, Germany
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Bastian Fromm
- UiT The Arctic University of Norway, Tromsø, Norway
- SciLifeLab, Stockholm University, Stockholm, Sweden
| | - Ivano Legnini
- Laboratory of Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Hannoversche Str 28, 10115 Berlin, Germany
| | - Salah Ayoub
- Laboratory of Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Hannoversche Str 28, 10115 Berlin, Germany
| | - Gianluca Polese
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Valeria Maselli
- Department of Biology, University of Naples Federico II, Naples, Italy
| | | | - Jakob Vinther
- School of Earth Sciences, University of Bristol, Bristol, UK
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Ruth Styfhals
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven, Belgium
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Eve Seuntjens
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven, Belgium
| | - Anna Di Cosmo
- Department of Biology, University of Naples Federico II, Naples, Italy
| | | | - Nikolaus Rajewsky
- Laboratory of Systems Biology of Gene Regulatory Elements, Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Hannoversche Str 28, 10115 Berlin, Germany
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Vergara-Ovalle F, Gonzalez-Navarrete A, Sánchez-Castillo H. Characterization of the Brain of the Red Mayan Octopus (Octopus maya Voss and Solis, 1966). J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022050118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
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15
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Abstract
Temporality is one of the criteria that Birch has advanced for areas of cognitive ability that may underlie animal sentience. An ability to integrate and use information across time must be more than simply learning pieces of information and retrieving them. This paper looks at such wider use of information by octopuses across time. It evaluates accumulation of information about one’s place in space, as used across immediate egocentric localization by cuttlefish and medium distance navigation in octopuses. Information about useful items in the environment can be incorporated for future use by octopuses, including for shelter in antipredator situations. Finding prey is not random but can be predicted by environmental cues, especially by cuttlefish about future contingencies. Finally, the paper examines unlimited associative learning and constraints on learning, and the ability of cephalopods to explore and seek out information, even by play, for future use.
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16
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Baden T, Nilsson DE. Is our retina really upside down? Curr Biol 2022; 32:R300-R303. [PMID: 35413251 DOI: 10.1016/j.cub.2022.02.065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In the vertebrate eye, photoreceptors are covered beneath a thick sheet of neural retina and face away from the light. This seemingly awkward arrangement has led to the popular notion that our retinas are upside down, implying a deep design flaw. Baden and Nilsson argue that, from an evolutionary perspective, an inverted design actually offers many notable benefits that might have never been exploited if things had started off the other way round.
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Affiliation(s)
- Tom Baden
- School of Life Sciences, University of Sussex, Brighton, UK; Institute of Ophthalmic Research, University of Tübingen, Tübingen, Germany.
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Jacobs RE. Diffusion MRI Connections in the Octopus Brain. Exp Neurobiol 2022; 31:17-28. [PMID: 35256541 PMCID: PMC8907252 DOI: 10.5607/en21047] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 02/15/2022] [Accepted: 02/18/2022] [Indexed: 12/27/2022] Open
Abstract
Using high angle resolution diffusion magnetic resonance imaging (HARDI) with fiber tractography analysis we map out a meso-scale connectome of the Octopus bimaculoides brain. The brain of this cephalopod has a qualitatively different organization than that of vertebrates, yet it exhibits complex behavior, an elaborate sensory system and high cognitive abilities. Over the last 60 years wide ranging and detailed studies of octopus brain anatomy have been undertaken, including classical histological sectioning/staining, electron microscopy and neuronal tract tracing with injected dyes. These studies have elucidated many neuronal connections within and among anatomical structures. Diffusion MRI based tractography utilizes a qualitatively different method of tracing connections within the brain and offers facile three-dimensional images of anatomy and connections that can be quantitatively analyzed. Twenty-five separate lobes of the brain were segmented in the 3D MR images of each of three samples, including all five sub-structures in the vertical lobe. These parcellations were used to assay fiber tracings between lobes. The connectivity matrix constructed from diffusion MRI data was largely in agreement with that assembled from earlier studies. The one major difference was that connections between the vertical lobe and more basal supra-esophageal structures present in the literature were not found by MRI. In all, 92 connections between the 25 different lobes were noted by diffusion MRI: 53 between supra-esophageal lobes and 26 between the optic lobes and other structures. These represent the beginnings of a mesoscale connectome of the octopus brain.
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Affiliation(s)
- Russell E Jacobs
- Department of Physiology and Neuroscience, Zilkha Neurogenetics Institute, Keck School of Medicine of USC, Los Angeles, CA 90089-2821, USA
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Gutnick T, Kuba MJ, Di Cosmo A. Neuroecology: Forces that shape the octopus brain. Curr Biol 2022; 32:R131-R135. [DOI: 10.1016/j.cub.2021.12.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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