1
|
Neacsu D, Crook RJ. Repeating ultrastructural motifs provide insight into the organization of the octopus arm nervous system. Curr Biol 2024:S0960-9822(24)01219-3. [PMID: 39326412 DOI: 10.1016/j.cub.2024.09.007] [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: 05/15/2024] [Revised: 08/19/2024] [Accepted: 09/04/2024] [Indexed: 09/28/2024]
Abstract
The peripheral nervous system of the octopus is among the most complex of any animal. In each arm, hundreds of serial ganglia form a central core of nervous tissue processing sensory input, issuing motor commands, and exchanging information with the central brain.1,2,3,4,5 In addition to the central cord, there are two other types of neural elements: fine intramuscular nerve cords (INCs)6,7 and small sucker ganglia at the base of each sucker.2,6,8,9 Connections between these different elements and the structural organization of the arm nervous system remain poorly understood, despite decades of interest and a more recent explosion of studies of the cephalopod nervous system.8,10,11,12,13,14,15 Here, we use serial blockface electron microscopy to reconstruct large volumes of an arm from Octopus bocki at the base and toward the tip, mapping connections between the various neural elements and their relationship to the muscle and skin. We show that the ganglia follow an alternating mirror-image pattern along the arm, where the left or right-sided location of successive suckers determines ganglionic orientation. We also describe previously unrecognized patterns in (1) continuity of oblique connectives between the INCs that encircle the arm; (2) repeatable structures of the major blood vessel branches and nerve connectives within each ganglion; (3) clustering of rare, unusually large neurons within the cell body layers; and (4) division of the cortex into repeating columns. These new findings from the first 3DEM reconstruction of the arm should greatly facilitate future studies of octopus neurobiology, particularly sensori-motor integration and arm control.
Collapse
Affiliation(s)
- Diana Neacsu
- Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132, USA.
| | - Robyn J Crook
- Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132, USA.
| |
Collapse
|
2
|
Wu M, Afridi WH, Wu J, Afridi RH, Wang K, Zheng X, Wang C, Xie G. Octopus-Inspired Underwater Soft Robotic Gripper with Crawling and Swimming Capabilities. RESEARCH (WASHINGTON, D.C.) 2024; 7:0456. [PMID: 39206446 PMCID: PMC11350063 DOI: 10.34133/research.0456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Accepted: 07/27/2024] [Indexed: 09/04/2024]
Abstract
Can a robotic gripper only operate when attached to a robotic arm? The application space of the traditional gripper is limited by the robotic arm. Giving robot grippers the ability to move will expand their range of applications. Inspired by rich behavioral repertoire observed in octopus, we implement an integrated multifunctional soft robotic gripper with 6 independently controlled Arms. It can execute 8 different gripping actions for different objects, such as irregular rigid/soft objects, elongated objects with arbitrary orientation, and plane/curved objects with larger sizes than the grippers. Moreover, the soft gripper can realize omnidirectional crawling and swimming by itself. The soft gripper can perform highly integrated tasks of releasing, crawling, swimming, grasping, and retrieving objects in a confined underwater environment. Experimental results demonstrate that the integrated capabilities of multimodal adaptive grasping and omnidirectional motions enable dexterous manipulations that traditional robotic arms cannot achieve. The soft gripper may apply to highly integrated and labor-intensive tasks in unstructured underwater environments, including ocean litter collecting, capture fishery, and archeological exploration.
Collapse
Affiliation(s)
- Mingxin Wu
- State Key Laboratory for Turbulence and Complex Systems, Intelligent Biomimetic Design Lab, College of Engineering,
Peking University, Beijing 100871, China
| | - Waqar Hussain Afridi
- State Key Laboratory for Turbulence and Complex Systems, Intelligent Biomimetic Design Lab, College of Engineering,
Peking University, Beijing 100871, China
| | - Jiaxi Wu
- State Key Laboratory for Turbulence and Complex Systems, Intelligent Biomimetic Design Lab, College of Engineering,
Peking University, Beijing 100871, China
| | - Rahdar Hussain Afridi
- State Key Laboratory for Turbulence and Complex Systems, Intelligent Biomimetic Design Lab, College of Engineering,
Peking University, Beijing 100871, China
| | - Kaiwei Wang
- State Key Laboratory for Turbulence and Complex Systems, Intelligent Biomimetic Design Lab, College of Engineering,
Peking University, Beijing 100871, China
| | - Xingwen Zheng
- State Key Laboratory for Turbulence and Complex Systems, Intelligent Biomimetic Design Lab, College of Engineering,
Peking University, Beijing 100871, China
| | - Chen Wang
- State Key Laboratory for Turbulence and Complex Systems, Intelligent Biomimetic Design Lab, College of Engineering,
Peking University, Beijing 100871, China
- National Engineering Research Center of Software Engineering,
Peking University, Beijing 100871, China
| | - Guangming Xie
- State Key Laboratory for Turbulence and Complex Systems, Intelligent Biomimetic Design Lab, College of Engineering,
Peking University, Beijing 100871, China
- Institute of Ocean Research,
Peking University, Beijing 100871, China
| |
Collapse
|
3
|
Salvador B, Cabanellas‐Reboredo M, Garci ME, González ÁF, Hernández‐Urcera J. The best defense is a good offense: Anti-predator behavior of the common octopus ( Octopus vulgaris) against conger eel attacks. Ecol Evol 2024; 14:e11107. [PMID: 38510541 PMCID: PMC10951491 DOI: 10.1002/ece3.11107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 02/16/2024] [Accepted: 02/21/2024] [Indexed: 03/22/2024] Open
Abstract
We present the description of defensive behavior in wild Octopus vulgaris against conger eel (Conger conger) attacks based on three video sequences recorded by recreational SCUBA divers in the eastern Atlantic off the coast of Galicia (NW Spain) and in the Cantabrian Sea (NW Spain). These records document common traits in defensive behavior: (1) the octopuses enveloped the conger eel's head to obscure its view; (2) they covered the eel's gills in an attempt to suffocate it; (3) they released ink; (4) the octopuses lost some appendages because of the fight. In the third video, the octopus did not exhibit the defensive behavior described in the first two videos due to an inability to utilize its arms in defense, and the conger eel's success in capturing octopuses is discussed. Additionally, both the cost that the octopus could face by losing some arms during the fight and whether the experience it acquires can be an advantage for future encounters are analyzed. The defensive behavior exhibited by octopuses in this study highlights their ability to survive in a hostile environment and serves as an example of the extensive repertoire of anti-predator strategies employed by these cephalopods.
Collapse
Affiliation(s)
- Beatriz Salvador
- ECOBIOMAR Research GroupInstitute of Marine Research (IIM‐CSIC)VigoSpain
| | | | - Manuel E. Garci
- ECOBIOMAR Research GroupInstitute of Marine Research (IIM‐CSIC)VigoSpain
| | - Ángel F. González
- ECOBIOMAR Research GroupInstitute of Marine Research (IIM‐CSIC)VigoSpain
| | | |
Collapse
|
4
|
Hochner B, Zullo L, Shomrat T, Levy G, Nesher N. Embodied mechanisms of motor control in the octopus. Curr Biol 2023; 33:R1119-R1125. [PMID: 37875094 DOI: 10.1016/j.cub.2023.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Abstract
Achieving complex behavior in soft-bodied animals is a hard task, because their body morphology is not constrained by a fixed number of jointed elements, as in skeletal animals, and thus the control system has to deal with practically an infinite number of control variables (degrees of freedom). Almost 30 years of research on Octopus vulgaris motor control has revealed that octopuses efficiently control their body with strategies that emerged during the adaptive coevolution of their nervous system and body morphology. In this minireview, we highlight principles of embodied organization that were revealed by studying octopus motor control, and that are used as inspiration for soft robotics. We describe the evolved solutions to the problem, implemented from the lowest level, the muscular system, to the network organization in higher motor control centers of the octopus brain. We show how the higher motor control centers, where the sensory-motor interface lies, can control and coordinate limbs with large degrees of freedom without using body-part maps to represent sensory and motor information, as they do in vertebrates. We demonstrate how this unique control mechanism, which allows efficient control of the body in a large variety of behaviors, is embodied within the animal's body morphology.
Collapse
Affiliation(s)
- Binyamin Hochner
- Department of Neurobiology, Silberman Life Sciences Institute, Hebrew University, Jerusalem, Israel.
| | - Letizia Zullo
- IRCSS Ospedale Policlinico San Martino, Genova, Italy.
| | - Tal Shomrat
- Faculty of Marine Sciences, Ruppin Academic Center, Michmoret, Israel
| | - Guy Levy
- Department of Neurobiology, Silberman Life Sciences Institute, Hebrew University, Jerusalem, Israel
| | - Nir Nesher
- Faculty of Marine Sciences, Ruppin Academic Center, Michmoret, Israel
| |
Collapse
|
5
|
Macchi F, Edsinger E, Sadler KC. Epigenetic machinery is functionally conserved in cephalopods. BMC Biol 2022; 20:202. [PMID: 36104784 PMCID: PMC9476566 DOI: 10.1186/s12915-022-01404-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 09/07/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Epigenetic regulatory mechanisms are divergent across the animal kingdom, yet these mechanisms are not well studied in non-model organisms. Unique features of cephalopods make them attractive for investigating behavioral, sensory, developmental, and regenerative processes, and recent studies have elucidated novel features of genome organization and gene and transposon regulation in these animals. However, it is not known how epigenetics regulates these interesting cephalopod features. We combined bioinformatic and molecular analysis of Octopus bimaculoides to investigate the presence and pattern of DNA methylation and examined the presence of DNA methylation and 3 histone post-translational modifications across tissues of three cephalopod species. RESULTS We report a dynamic expression profile of the genes encoding conserved epigenetic regulators, including DNA methylation maintenance factors in octopus tissues. Levels of 5-methyl-cytosine in multiple tissues of octopus, squid, and bobtail squid were lower compared to vertebrates. Whole genome bisulfite sequencing of two regions of the brain and reduced representation bisulfite sequencing from a hatchling of O. bimaculoides revealed that less than 10% of CpGs are methylated in all samples, with a distinct pattern of 5-methyl-cytosine genome distribution characterized by enrichment in the bodies of a subset of 14,000 genes and absence from transposons. Hypermethylated genes have distinct functions and, strikingly, many showed similar expression levels across tissues while hypomethylated genes were silenced or expressed at low levels. Histone marks H3K27me3, H3K9me3, and H3K4me3 were detected at different levels across tissues of all species. CONCLUSIONS Our results show that the DNA methylation and histone modification epigenetic machinery is conserved in cephalopods, and that, in octopus, 5-methyl-cytosine does not decorate transposable elements, but is enriched on the gene bodies of highly expressed genes and could cooperate with the histone code to regulate tissue-specific gene expression.
Collapse
Affiliation(s)
- Filippo Macchi
- Program in Biology, New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates
| | - Eric Edsinger
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Kirsten C Sadler
- Program in Biology, New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates.
| |
Collapse
|
6
|
Sivitilli DM, Smith JR, Gire DH. Lessons for Robotics From the Control Architecture of the Octopus. Front Robot AI 2022; 9:862391. [PMID: 35923303 PMCID: PMC9339708 DOI: 10.3389/frobt.2022.862391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 06/13/2022] [Indexed: 11/13/2022] Open
Abstract
Biological and artificial agents are faced with many of the same computational and mechanical problems, thus strategies evolved in the biological realm can serve as inspiration for robotic development. The octopus in particular represents an attractive model for biologically-inspired robotic design, as has been recognized for the emerging field of soft robotics. Conventional global planning-based approaches to controlling the large number of degrees of freedom in an octopus arm would be computationally intractable. Instead, the octopus appears to exploit a distributed control architecture that enables effective and computationally efficient arm control. Here we will describe the neuroanatomical organization of the octopus peripheral nervous system and discuss how this distributed neural network is specialized for effectively mediating decisions made by the central brain and the continuous actuation of limbs possessing an extremely large number of degrees of freedom. We propose top-down and bottom-up control strategies that we hypothesize the octopus employs in the control of its soft body. We suggest that these strategies can serve as useful elements in the design and development of soft-bodied robotics.
Collapse
Affiliation(s)
- Dominic M. Sivitilli
- Department of Psychology, University of Washington, Seattle, WA, United States
- Astrobiology Program, University of Washington, Seattle, WA, United States
- *Correspondence: Dominic M. Sivitilli, ; David H. Gire,
| | - Joshua R. Smith
- Paul G. Allen School of Computer Science and Engineering, University of Washington, Seattle, WA, United States
- Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, United States
| | - David H. Gire
- Department of Psychology, University of Washington, Seattle, WA, United States
- Astrobiology Program, University of Washington, Seattle, WA, United States
- *Correspondence: Dominic M. Sivitilli, ; David H. Gire,
| |
Collapse
|
7
|
Frey ST, Haque ABMT, Tutika R, Krotz EV, Lee C, Haverkamp CB, Markvicka EJ, Bartlett MD. Octopus-inspired adhesive skins for intelligent and rapidly switchable underwater adhesion. SCIENCE ADVANCES 2022; 8:eabq1905. [PMID: 35857521 PMCID: PMC9278861 DOI: 10.1126/sciadv.abq1905] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 06/01/2022] [Indexed: 05/21/2023]
Abstract
The octopus couples controllable adhesives with intricately embedded sensing, processing, and control to manipulate underwater objects. Current synthetic adhesive-based manipulators are typically manually operated without sensing or control and can be slow to activate and release adhesion, which limits system-level manipulation. Here, we couple switchable, octopus-inspired adhesives with embedded sensing, processing, and control for robust underwater manipulation. Adhesion strength is switched over 450× from the ON to OFF state in <50 ms over many cycles with an actively controlled membrane. Systematic design of adhesive geometry enables adherence to nonideal surfaces with low preload and independent control of adhesive strength and adhesive toughness for strong and reliable attachment and easy release. Our bio-inspired nervous system detects objects and autonomously triggers the switchable adhesives. This is implemented into a wearable glove where an array of adhesives and sensors creates a biomimetic adhesive skin to manipulate diverse underwater objects.
Collapse
Affiliation(s)
- Sean T. Frey
- Materials Science and Engineering, Iowa State University, Ames, IA 50010, USA
| | - A. B. M. Tahidul Haque
- Mechanical Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, VA 24061, USA
| | - Ravi Tutika
- Mechanical Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, VA 24061, USA
- Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA 24061, USA
| | - Elizabeth V. Krotz
- Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA 24061, USA
| | - Chanhong Lee
- Mechanical Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, VA 24061, USA
| | - Cole B. Haverkamp
- Materials Science and Engineering, Iowa State University, Ames, IA 50010, USA
| | - Eric J. Markvicka
- Department of Mechanical and Materials Engineering, Smart Materials and Robotics Laboratory, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Michael D. Bartlett
- Mechanical Engineering, Soft Materials and Structures Lab, Virginia Tech, Blacksburg, VA 24061, USA
- Macromolecules Innovation Institute, Virginia Tech, Blacksburg, VA 24061, USA
- Corresponding author.
| |
Collapse
|
8
|
Ponte G, Chiandetti C, Edelman DB, Imperadore P, Pieroni EM, Fiorito G. Cephalopod Behavior: From Neural Plasticity to Consciousness. Front Syst Neurosci 2022; 15:787139. [PMID: 35495582 PMCID: PMC9039538 DOI: 10.3389/fnsys.2021.787139] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/22/2021] [Indexed: 11/18/2022] Open
Abstract
It is only in recent decades that subjective experience - or consciousness - has become a legitimate object of scientific inquiry. As such, it represents perhaps the greatest challenge facing neuroscience today. Subsumed within this challenge is the study of subjective experience in non-human animals: a particularly difficult endeavor that becomes even more so, as one crosses the great evolutionary divide between vertebrate and invertebrate phyla. Here, we explore the possibility of consciousness in one group of invertebrates: cephalopod molluscs. We believe such a review is timely, particularly considering cephalopods' impressive learning and memory abilities, rich behavioral repertoire, and the relative complexity of their nervous systems and sensory capabilities. Indeed, in some cephalopods, these abilities are so sophisticated that they are comparable to those of some higher vertebrates. Following the criteria and framework outlined for the identification of hallmarks of consciousness in non-mammalian species, here we propose that cephalopods - particularly the octopus - provide a unique test case among invertebrates for examining the properties and conditions that, at the very least, afford a basal faculty of consciousness. These include, among others: (i) discriminatory and anticipatory behaviors indicating a strong link between perception and memory recall; (ii) the presence of neural substrates representing functional analogs of thalamus and cortex; (iii) the neurophysiological dynamics resembling the functional signatures of conscious states in mammals. We highlight the current lack of evidence as well as potentially informative areas that warrant further investigation to support the view expressed here. Finally, we identify future research directions for the study of consciousness in these tantalizing animals.
Collapse
Affiliation(s)
- Giovanna Ponte
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | | | - David B. Edelman
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH, United States
- Association for Cephalopod Research ‘CephRes' a non-profit Organization, Naples, Italy
| | - Pamela Imperadore
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | | | - Graziano Fiorito
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| |
Collapse
|
9
|
Carls-Diamante S. Where Is It Like to Be an Octopus? Front Syst Neurosci 2022; 16:840022. [PMID: 35401127 PMCID: PMC8988249 DOI: 10.3389/fnsys.2022.840022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/17/2022] [Indexed: 12/02/2022] Open
Abstract
The cognitive capacities and behavioural repertoire of octopuses have led to speculation that these animals may possess consciousness. However, the nervous system of octopuses is radically different from those typically associated with conscious experience: rather than being centralised and profoundly integrated, the octopus nervous system is distributed into components with considerable functional autonomy from each other. Of particular note is the arm nervous system: when severed, octopus arms still exhibit behaviours that are nearly identical to those exhibited when the animal is intact. Given these factors, there is reason to speculate that if octopuses do possess consciousness, it may be of a form highly dissimilar to familiar models. In particular, it may be that the octopus arm is capable of supporting an idiosyncratic field of consciousness. As such, in addition to the likelihood that there is something it is like to be an octopus, there may also be something it is like to be an octopus arm. This manuscript explores this possibility.
Collapse
|
10
|
Abstract
It is always difficult to even advance possible dimensions of consciousness, but Birch et al., 2020 have suggested four possible dimensions and this review discusses the first, perceptual richness, with relation to octopuses. They advance acuity, bandwidth, and categorization power as possible components. It is first necessary to realize that sensory richness does not automatically lead to perceptual richness and this capacity may not be accessed by consciousness. Octopuses do not discriminate light wavelength frequency (color) but rather its plane of polarization, a dimension that we do not understand. Their eyes are laterally placed on the head, leading to monocular vision and head movements that give a sequential rather than simultaneous view of items, possibly consciously planned. Details of control of the rich sensorimotor system of the arms, with 3/5 of the neurons of the nervous system, may normally not be accessed to the brain and thus to consciousness. The chromatophore-based skin appearance system is likely open loop, and not available to the octopus’ vision. Conversely, in a laboratory situation that is not ecologically valid for the octopus, learning about shapes and extents of visual figures was extensive and flexible, likely consciously planned. Similarly, octopuses’ local place in and navigation around space can be guided by light polarization plane and visual landmark location and is learned and monitored. The complex array of chemical cues delivered by water and on surfaces does not fit neatly into the components above and has barely been tested but might easily be described as perceptually rich. The octopus’ curiosity and drive to investigate and gain more information may mean that, apart from richness of any stimulus situation, they are consciously driven to seek out more information. This review suggests that cephalopods may not have a similar type of intelligence as the ‘higher’ vertebrates, they may not have similar dimensions or contents of consciousness, but that such a capacity is present nevertheless.
Collapse
|
11
|
Katz I, Shomrat T, Nesher N. Feel the light: sight-independent negative phototactic response in octopus arms. J Exp Biol 2021; 224:jeb.237529. [PMID: 33536305 DOI: 10.1242/jeb.237529] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 01/23/2021] [Indexed: 11/20/2022]
Abstract
Controlling the octopus's flexible hyper-redundant body is a challenging task. It is assumed that the octopus has poor proprioception which has driven the development of unique mechanisms for efficient body control. Here we report on such a mechanism: a phototactic response of extraocular photoreception. Extraocular photoreception has been observed in many and diverse species. Previous research on cephalopods revealed that increased illumination on their skin evokes chromatophore expansion. Recently, the mechanism was investigated and has been termed 'light-activated chromatophore expansion' (LACE). In this work we show that in response to illumination, the arm tip reacts in a reflex-like manner, folding in and moving away from the light beam. We performed a set of behavioral experiments and surgical manipulations to elucidate and characterize this phototactic response. We found that in contrast to the local activation and control of LACE, the phototactic response is mediated by the brain, although it is expressed in a reflex-like pattern. Our research results and observations led us to propose that the phototaxis is a means for protecting the arms in an instinctive manner from potential daytime predators such as fish and crabs, that could identify the worm-like tips as food. Indeed, observations of the octopuses revealed that their arm tips are folded in during the daytime, whereas at night they are extended. Thus, the phototactic response might compensate for the octopus's poor proprioception by keeping their arms folded in illuminated areas, without the need to be aware of their state.
Collapse
Affiliation(s)
- Itamar Katz
- Faculty of Marine Sciences, Ruppin Academic Center, Michmoret 40297, Israel
| | - Tal Shomrat
- Faculty of Marine Sciences, Ruppin Academic Center, Michmoret 40297, Israel
| | - Nir Nesher
- Faculty of Marine Sciences, Ruppin Academic Center, Michmoret 40297, Israel
| |
Collapse
|
12
|
Gutnick T, Zullo L, Hochner B, Kuba MJ. Use of Peripheral Sensory Information for Central Nervous Control of Arm Movement by Octopus vulgaris. Curr Biol 2020; 30:4322-4327.e3. [PMID: 32916119 DOI: 10.1016/j.cub.2020.08.037] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 07/16/2020] [Accepted: 08/10/2020] [Indexed: 01/04/2023]
Abstract
Octopuses are active predators with highly flexible bodies and rich behavioral repertoires [1-3]. They display advanced cognitive abilities, and the size of their large nervous system rivals that of many mammals. However, only one third of the neurons constitute the CNS, while the rest are located in an elaborate PNS, including eight arms, each containing myriad sensory receptors of various modalities [2-4]. This led early workers to question the extent to which the CNS is privy to non-visual sensory input from the periphery and to suggest that it has limited capacity to finely control arm movement [3-5]. This conclusion seemed reasonable considering the size of the PNS and the results of early behavioral tests [3, 6-8]. We recently demonstrated that octopuses use visual information to control goal-directed complex single arm movements [9]. However, that study did not establish whether animals use information from the arm itself [9-12]. We here report on development of two-choice, single-arm mazes that test the ability of octopuses to perform operant learning tasks that mimic normal tactile exploration behavior and require the non-peripheral neural circuitry to use focal sensory information originating in single arms [1, 10]. We show that the CNS of the octopus uses peripheral information about arm motion as well as tactile input to accomplish learning tasks that entail directed control of movement. We conclude that although octopus arms have a great capacity to act independently, they are also subject to central control, allowing well-organized, purposeful behavior of the organism as a whole.
Collapse
Affiliation(s)
- Tamar Gutnick
- Department of Neurobiology, Institute of Life Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel; Okinawa Institute of Science and Technology, Graduate University, 904-0495 Okinawa, Japan.
| | - Letizia Zullo
- Center for Micro-BioRobotics & Center for Synaptic Neuroscience and Technology (NSYN), Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132, Genoa, Italy
| | - Binyamin Hochner
- Department of Neurobiology, Institute of Life Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
| | - Michael J Kuba
- Department of Neurobiology, Institute of Life Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel; Okinawa Institute of Science and Technology, Graduate University, 904-0495 Okinawa, Japan.
| |
Collapse
|
13
|
Birch J, Schnell AK, Clayton NS. Dimensions of Animal Consciousness. Trends Cogn Sci 2020; 24:789-801. [PMID: 32830051 PMCID: PMC7116194 DOI: 10.1016/j.tics.2020.07.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/21/2020] [Accepted: 07/23/2020] [Indexed: 01/29/2023]
Abstract
How does consciousness vary across the animal kingdom? Are some animals 'more conscious' than others? This article presents a multidimensional framework for understanding interspecies variation in states of consciousness. The framework distinguishes five key dimensions of variation: perceptual richness, evaluative richness, integration at a time, integration across time, and self-consciousness. For each dimension, existing experiments that bear on it are reviewed and future experiments are suggested. By assessing a given species against each dimension, we can construct a consciousness profile for that species. On this framework, there is no single scale along which species can be ranked as more or less conscious. Rather, each species has its own distinctive consciousness profile.
Collapse
Affiliation(s)
- Jonathan Birch
- Centre for Philosophy of Natural and Social Science, London School of Economics and Political Science, Houghton Street, London, WC2A 2AE, UK.
| | - Alexandra K Schnell
- Comparative Cognition Lab, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK
| | - Nicola S Clayton
- Comparative Cognition Lab, Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK
| |
Collapse
|
14
|
Schnell AK, Amodio P, Boeckle M, Clayton NS. How intelligent is a cephalopod? Lessons from comparative cognition. Biol Rev Camb Philos Soc 2020; 96:162-178. [DOI: 10.1111/brv.12651] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 08/22/2020] [Accepted: 08/25/2020] [Indexed: 11/30/2022]
Affiliation(s)
| | - Piero Amodio
- Department of Psychology University of Cambridge Cambridge UK
- Department of Biology and Evolution of Marine Organisms Stazione Zoologica Anton Dohrn Naples Italy
| | - Markus Boeckle
- Department of Psychology University of Cambridge Cambridge UK
- Department of Cognitive Biology University of Vienna Vienna Austria
- Karl Landsteiner University of Health Science Krems an der Donau Austria
| | | |
Collapse
|
15
|
Sensorial Hierarchy in Octopus vulgaris's Food Choice: Chemical vs. Visual. Animals (Basel) 2020; 10:ani10030457. [PMID: 32164232 PMCID: PMC7143185 DOI: 10.3390/ani10030457] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 02/28/2020] [Accepted: 03/05/2020] [Indexed: 12/01/2022] Open
Abstract
Simple Summary Coleoids are cephalopods endowed with a highly sophisticated nervous system with keen sense organs and an exceptionally large brain that includes more than 30 differentiated lobes. Within this group, Octopus vulgaris, well known as an intelligent soft-bodied animal, has a significant number of lobes in the nervous system dedicated to decoding and integrating visual, tactile, and chemosensory perceptions. In this study, we aimed to understand the key role of chemical and visual cues during food selection in O. vulgaris. We first defined the preferred food, and subsequently, we set up five different problem-solving tasks, in which the animal’s choice is guided by visual and chemosensory signals, either alone or together, to evaluate whether individual O. vulgaris uses a sensorial hierarchy. Our behavioural experiments show that this species does integrate different sensory information from chemical and visual cues during food selection; however, our results indicate that chemical perception provides accurate and faster information leading to food choice. This research opens new perspectives on O. vulgaris’ predation strategies. Abstract Octopus vulgaris possesses highly sophisticated sense organs, processed by the nervous system to generate appropriate behaviours such as finding food, avoiding predators, identifying conspecifics, and locating suitable habitat. Octopus uses multiple sensory modalities during the searching and selection of food, in particular, the chemosensory and visual cues. Here, we examined food choice in O. vulgaris in two ways: (1) We tested octopus’s food preference among three different kinds of food, and established anchovy as the preferred choice (66.67%, Friedman test p < 0.05); (2) We exposed octopus to a set of five behavioural experiments in order to establish the sensorial hierarchy in food choice, and to evaluate the performance based on the visual and chemical cues, alone or together. Our data show that O. vulgaris integrates sensory information from chemical and visual cues during food choice. Nevertheless, food choice resulted in being more dependent on chemical cues than visual ones (88.9%, Friedman test p < 0.05), with a consistent decrease of the time spent identifying the preferred food. These results define the role played by the senses with a sensorial hierarchy in food choice, opening new perspectives on the O. vulgaris’ predation strategies in the wild, which until today were considered to rely mainly on visual cues.
Collapse
|
16
|
Fouke KE, Rhodes HJ. Electrophysiological and Motor Responses to Chemosensory Stimuli in Isolated Cephalopod Arms. THE BIOLOGICAL BULLETIN 2020; 238:1-11. [PMID: 32163724 DOI: 10.1086/707837] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
While there is behavioral and anatomical evidence that coleoid cephalopods use their arms to "taste" substances in the environment, the neurophysiology of chemosensation has been largely unexamined. The range and sensitivity of detectable chemosensory stimuli, and the processing of chemosensory information, are unknown. To begin to address these issues, we developed a technique for recording neurophysiological responses from isolated arms, allowing us to test responses to biologically relevant stimuli. We tested arms from both a pelagic species (Doryteuthis pealeii) and a benthic species (Octopus bimaculoides) by attaching a suction electrode to the axial nerve cord to record neural activity in response to chemical stimuli. Doryteuthis pealeii arms showed anecdotal responses to some stimuli but generally did not tolerate the preparation; tissue was nonviable within minutes ex vivo. Octopus bimaculoides arms were used successfully, with tissue remaining healthy and responsive for several hours. Arms responded strongly to fish skin extract, glycine, methionine, and conspecific skin extract but not to cephalopod ink or seawater controls. Motor responses were also observed in response to detected stimuli. These results suggest that chemosensory receptor cells on O. bimaculoides arms were able to detect environmentally relevant chemicals and drive local motor responses within the arm. Further exploration of potential chemical stimuli for O. bimaculoides arms, as well as investigations into the neural processing within the arm, could enhance our understanding of how this species uses its arms to explore its environment. While not successful in D. pealeii, this technique could be attempted with other cephalopod species, as comparative questions remain of interest.
Collapse
|
17
|
Naser Moghadasi A. When an octopus has MS: Application of neurophysiology and immunology of octopuses for multiple sclerosis. Med Hypotheses 2019; 131:109297. [PMID: 31443774 DOI: 10.1016/j.mehy.2019.109297] [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: 04/25/2019] [Revised: 06/14/2019] [Accepted: 06/30/2019] [Indexed: 11/30/2022]
Abstract
Multiple sclerosis (MS) is an immune-mediated disease which can cause different symptoms due to the involvement of different regions of the central nervous system (CNS). Although this disease is characterized by the demyelination process, the most important feature of the disease is its degenerative nature. This nature is clinically manifested as progressive symptoms, especially in patients' walking, which can even lead to complete debilitation. Therefore, finding a treatment to prevent the degenerative processes is one of the most important goals in MS studies. To better understand the process and the effect of drugs, scientists use animal models which mostly consisting of mouse, rat, and monkey. In evolutionary terms, octopuses belong to the invertebrates which have many substantial differences with vertebrates. One of these differences is related to the nervous system of these organisms, which is divided into central and peripheral parts. The difference lies in the fact that the main volume of this system expands in the limbs of these organisms instead of their brain. This offers a kind of freedom of action and processing strength in the octopus limbs. Also, the brain of these organisms follows a non-somatotopic model. Although the complex actions of this organism are stimulated by the brain, in contrast to the human brain, this activity is not related to a specific region of the brain; rather the entire brain area of the octopus is activated during a process. Indeed, the brain mapping or the topological perception of a particular action, such as moving the limbs, reflects itself in how that activity is distributed in the octopus brain neurons. Accordingly, various actions are known with varying degrees of activity of neurons in the brain of octopus. Another important feature of octopuses is their ability to regenerate defective tissues including the central and peripheral nervous system. These characteristics raise the question of what features can an octopus show when it is used as an organism to create experimental autoimmune encephalomyelitis (EAE). Can the immune system damage of the octopus brain cause a regeneration process? Will the autonomy of the organs reduce the severity of the symptoms? This article seeks to provide evidence to prove that use of octopuses as laboratory samples for generation of EAE may open up new approaches for researchers to better approach MS.
Collapse
Affiliation(s)
- Abdorreza Naser Moghadasi
- Multiple Sclerosis Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
18
|
Hanley D, Gern K, Hauber ME, Grim T. Host Responses to Foreign Eggs across the Avian Visual Color Space. Am Nat 2019; 194:17-27. [DOI: 10.1086/703534] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
19
|
|
20
|
Hanley D, Grim T, Igic B, Samaš P, López AV, Shawkey MD, Hauber ME. Egg discrimination along a gradient of natural variation in eggshell coloration. Proc Biol Sci 2018; 284:rspb.2016.2592. [PMID: 28179521 PMCID: PMC5310612 DOI: 10.1098/rspb.2016.2592] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 01/10/2017] [Indexed: 11/12/2022] Open
Abstract
Accurate recognition of salient cues is critical for adaptive responses, but the underlying sensory and cognitive processes are often poorly understood. For example, hosts of avian brood parasites have long been assumed to reject foreign eggs from their nests based on the total degree of dissimilarity in colour to their own eggs, regardless of the foreign eggs' colours. We tested hosts' responses to gradients of natural (blue-green to brown) and artificial (green to purple) egg colours, and demonstrate that hosts base rejection decisions on both the direction and degree of colour dissimilarity along the natural, but not artificial, gradient of egg colours. Hosts rejected brown eggs and accepted blue-green eggs along the natural egg colour gradient, irrespective of the total perceived dissimilarity from their own egg's colour. By contrast, their responses did not vary along the artificial colour gradient. Our results demonstrate that egg recognition is specifically tuned to the natural gradient of avian eggshell colour and suggest a novel decision rule. These results highlight the importance of considering sensory reception and decision rules when studying perception, and illustrate that our understanding of recognition processes benefits from examining natural variation in phenotypes.
Collapse
Affiliation(s)
- Daniel Hanley
- Department of Biology, Long Island University - Post, Brookville, NY 11548-1300, USA
| | - Tomáš Grim
- Department of Zoology and Laboratory of Ornithology, Palacký University, Olomouc 77146, Czech Republic
| | - Branislav Igic
- Department of Biology, University of Akron, Akron, OH 44325, USA.,Division of Ecology and Evolution, Research School of Biology, Australian National University, Canberra 2601, Australia
| | - Peter Samaš
- Department of Zoology and Laboratory of Ornithology, Palacký University, Olomouc 77146, Czech Republic
| | - Analía V López
- Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1428EHA Buenos Aires, Argentina
| | - Matthew D Shawkey
- Department of Biology, University of Akron, Akron, OH 44325, USA.,Department of Biology, Evolution and Optics of Nanostructures Group, Ghent University, Ghent 9000, Belgium
| | - Mark E Hauber
- Department of Psychology, Hunter College and the Graduate Center of the City University of New York, New York, NY 10065, USA.,Department of Animal Biology, School of Integrative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| |
Collapse
|
21
|
Bellier JP, Xie Y, Farouk SM, Sakaue Y, Tooyama I, Kimura H. Immunohistochemical and biochemical evidence for the presence of serotonin-containing neurons and nerve fibers in the octopus arm. Brain Struct Funct 2017; 222:3043-3061. [PMID: 28247020 DOI: 10.1007/s00429-017-1385-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 02/08/2017] [Indexed: 01/08/2023]
Abstract
The octopus arm contains a tridimensional array of muscles with a massive sensory-motor system. We herein provide the first evidence for the existence of serotonin (5-HT) in the octopus arm nervous system and investigated its distribution using immunohistochemistry. 5-HT-like immunoreactive (5-HT-lir) nerve cell bodies were exclusively localized in the cellular layer of the axial nerve cord. Those cell bodies emitted 5-HT-lir nerve fibers in the direction of the sucker, the intramuscular nerves cords, the ganglion of the sucker, and the intrinsic musculature. Others 5-HT-lir nerve fibers were observed in various tissues, including the cerebrobrachial tract, the skin, and the blood vessels. 5-HT was detected by high-performance liquid chromatography in various regions of the octopus arm at levels matching the density of 5-HT-lir staining. The absence of 5-HT-lir interconnections between the cerebrobrachial tract and the other components of the axial nerve cord suggests that two types of 5-HT-lir innervation exist in the arm. One type, which originates from the brain, may innervate the periphery through the cerebrobrachial tract. Another type, which originates in the cellular layer of the axial nerve cord, may form an intrinsic network in the arm. In addition, 5-HT-lir fibers likely emitted from the neuropil of the axial nerve cord were found to project into cells showing staining for peripheral choline acetyltransferase, a marker of sensory cells of the sucker. Taken together, these observations suggest that intrinsic 5-HT-lir innervation may participate in the sensory transmission in the octopus arm.
Collapse
Affiliation(s)
- Jean-Pierre Bellier
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Otsu, Shiga, 520-2192, Japan.
| | - Yu Xie
- Life Science Research Center, Beihua University, Jilin, 132013, China
| | - Sameh Mohamed Farouk
- Department of Cytology and Histology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, 41522, Egypt
| | - Yuko Sakaue
- Department of Pediatrics, Shiga University of Medical Science, Otsu, Shiga, 520-2192, Japan
| | - Ikuo Tooyama
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Otsu, Shiga, 520-2192, Japan
| | - Hiroshi Kimura
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Otsu, Shiga, 520-2192, Japan
| |
Collapse
|
22
|
Holden-Dye L, Fiorito G, Ponte G. Invertebrate neuroscience and CephsInAction at the Mediterranean Society for Neuroscience Meeting Cagliari 2015. INVERTEBRATE NEUROSCIENCE 2015; 15:6. [PMID: 26386979 DOI: 10.1007/s10158-015-0182-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Invertebrate neuroscience, and in particular cephalopod research, is well represented in the Mediterranean region. Therefore, the recent meeting of the Mediterranean Society for Neuroscience in Santa Margherita di Pula, Sardinia (12-15 June 2015) provided an excellent opportunity for invertebrate contributions. Furthermore, the Chair of an EU COST Action for cephalopod research (FA1301; www.cephsinaction.org ), Giovanna Ponte, together with Graziano Fiorito from the Stazione Zoologica, Naples, aligned a meeting of research groups working in the field of cephalopod neurophysiology from across Europe to coincide with the neuroscience meeting. This provided an exciting forum for exchange of ideas. Here we provide brief highlights of both events and an explanation of the activities of the COST Action for the broader invertebrate neuroscience community.
Collapse
Affiliation(s)
- Lindy Holden-Dye
- Centre for Biological Sciences, Building 85, Highfield Campus, Southampton, SO17 1BJ, UK.
| | - Graziano Fiorito
- Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Naples, Italy
| | - Giovanna Ponte
- Cephalopod Research (CephRes), Via dei Fiorentini, 80133, Naples, Italy
| |
Collapse
|
23
|
Tozzi A. Information processing in the CNS: a supramolecular chemistry? Cogn Neurodyn 2015; 9:463-77. [PMID: 26379797 DOI: 10.1007/s11571-015-9337-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 02/02/2015] [Accepted: 03/03/2015] [Indexed: 12/30/2022] Open
Abstract
How does central nervous system process information? Current theories are based on two tenets: (a) information is transmitted by action potentials, the language by which neurons communicate with each other-and (b) homogeneous neuronal assemblies of cortical circuits operate on these neuronal messages where the operations are characterized by the intrinsic connectivity among neuronal populations. In this view, the size and time course of any spike is stereotypic and the information is restricted to the temporal sequence of the spikes; namely, the "neural code". However, an increasing amount of novel data point towards an alternative hypothesis: (a) the role of neural code in information processing is overemphasized. Instead of simply passing messages, action potentials play a role in dynamic coordination at multiple spatial and temporal scales, establishing network interactions across several levels of a hierarchical modular architecture, modulating and regulating the propagation of neuronal messages. (b) Information is processed at all levels of neuronal infrastructure from macromolecules to population dynamics. For example, intra-neuronal (changes in protein conformation, concentration and synthesis) and extra-neuronal factors (extracellular proteolysis, substrate patterning, myelin plasticity, microbes, metabolic status) can have a profound effect on neuronal computations. This means molecular message passing may have cognitive connotations. This essay introduces the concept of "supramolecular chemistry", involving the storage of information at the molecular level and its retrieval, transfer and processing at the supramolecular level, through transitory non-covalent molecular processes that are self-organized, self-assembled and dynamic. Finally, we note that the cortex comprises extremely heterogeneous cells, with distinct regional variations, macromolecular assembly, receptor repertoire and intrinsic microcircuitry. This suggests that every neuron (or group of neurons) embodies different molecular information that hands an operational effect on neuronal computation.
Collapse
Affiliation(s)
- Arturo Tozzi
- ASL Napoli 2 Nord, Distretto 45, Via Santa Chiara, 80023 Caivano, Naples, Italy
| |
Collapse
|
24
|
Tramacere F, Pugno NM, Kuba MJ, Mazzolai B. Unveiling the morphology of the acetabulum in octopus suckers and its role in attachment. Interface Focus 2015; 5:20140050. [PMID: 25657834 DOI: 10.1098/rsfs.2014.0050] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In recent years, the attachment mechanism of the octopus sucker has attracted the interest of scientists from different research areas, including biology, engineering, medicine and robotics. From a technological perspective, the main goal is to identify the underlying mechanisms involved in sucker attachment for use in the development of new generations of artificial devices and materials. Recently, the understanding of the morphology of the sucker has been significantly improved; however, the mechanisms that allow attachment remain largely unknown. In this work, we present new anatomical findings: specifically, a protuberance in the acetabular roof in five different octopus species; previously, this protuberance was identified by the authors in Octopus vulgaris. Moreover, we discuss the role of the protuberance and other anatomical structures in attachment with minimal energy consumption.
Collapse
Affiliation(s)
- Francesca Tramacere
- Center for Micro-BioRobotics , Istituto Italiano di Tecnologia , Viale Rinaldo Piaggio 34, Pontedera 56125 , Italy
| | - Nicola M Pugno
- Laboratory of Bio-inspired and Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering , University of Trento , via Mesiano 77, Trento 38123 , Italy ; Center for Materials and Microsystems , Fondazione Bruno Kessler , via Sommarive 18, Povo 38123 , Italy ; School of Engineering and Materials Science , Queen Mary University of London , Mile End Road, London E1 4NS , UK
| | - Michael J Kuba
- Max Planck Institute for Brain Research , Max Planck Institute , Max von Laue Strasse 4, Frankfurt 60438 , Germany
| | - Barbara Mazzolai
- Center for Micro-BioRobotics , Istituto Italiano di Tecnologia , Viale Rinaldo Piaggio 34, Pontedera 56125 , Italy
| |
Collapse
|
25
|
Portugal S. Octopuses don't get theirs arms in a twist. J Exp Biol 2014. [DOI: 10.1242/jeb.095034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
26
|
|
27
|
Abstract
How an octopus performs complex movements of its eight sucker-studded arms without entanglement has been a mystery. A new study has found that self-recognition of the octopus's skin by its suckers inhibits reflexive grasping of its own arms, simplifying the mechanisms needed to generate intricate arm behavior.
Collapse
Affiliation(s)
- Robyn J Crook
- Department of Integrative Biology and Pharmacology, University of Texas Medical School at Houston, 6431 Fannin St, Houston, TX 77030 USA
| | - Edgar T Walters
- Department of Integrative Biology and Pharmacology, University of Texas Medical School at Houston, 6431 Fannin St, Houston, TX 77030 USA.
| |
Collapse
|
28
|
Why an octopus never gets tangled. Nature 2014. [DOI: 10.1038/nature.2014.15204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|