1
|
Palmer RA, O’Reilly LJ, Carpenter J, Chenchiah IV, Robert D. An analysis of time-varying dynamics in electrically sensitive arthropod hairs to understand real-world electrical sensing. J R Soc Interface 2023; 20:20230177. [PMID: 37553992 PMCID: PMC10410214 DOI: 10.1098/rsif.2023.0177] [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: 03/27/2023] [Accepted: 07/17/2023] [Indexed: 08/10/2023] Open
Abstract
With increasing evidence of electroreception in terrestrial arthropods, an understanding of receptor level processes is vital to appreciating the capabilities and limits of this sense. Here, we examine the spatio-temporal sensitivity of mechanoreceptive filiform hairs in detecting electrical fields. We first present empirical data, highlighting the time-varying characteristics of biological electrical signals. After which, we explore how electrically sensitive hairs may respond to such stimuli. The main findings are: (i) oscillatory signals (elicited by wingbeats) influence the spatial sensitivity of hairs, unveiling an inextricable spatio-temporal link; (ii) wingbeat direction modulates spatial sensitivity; (iii) electrical wingbeats can be approximated by sinusoidally modulated DC signals; and (iv) for a moving point charge, maximum sensitivity occurs at a faster timescale than a hair's frequency-based tuning. Our results show that electro-mechanical sensory hairs may capture different spatio-temporal information, depending on an object's movement and wingbeat and in comparison with aero-acoustic stimuli. Crucially, we suggest that electrostatic and aero-acoustic signals may provide distinguishable channels of information for arthropods. Given the pervasiveness of electric fields in nature, our results suggest further study to understand electrostatics in the ecology of arthropods and to reveal unknown ecological relationships and novel interactions between species.
Collapse
Affiliation(s)
- Ryan A. Palmer
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
- School of Mathematics, University of Bristol, Fry Building, Woodland Road, Bristol BS8 1UG, UK
| | - Liam J. O’Reilly
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Jacob Carpenter
- School of Mathematics, University of Bristol, Fry Building, Woodland Road, Bristol BS8 1UG, UK
| | - Isaac V. Chenchiah
- School of Mathematics, University of Bristol, Fry Building, Woodland Road, Bristol BS8 1UG, UK
| | - Daniel Robert
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| |
Collapse
|
2
|
Passive electrolocation in terrestrial arthropods: Theoretical modelling of location detection. J Theor Biol 2023; 558:111357. [PMID: 36410450 DOI: 10.1016/j.jtbi.2022.111357] [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: 07/22/2022] [Revised: 10/23/2022] [Accepted: 11/14/2022] [Indexed: 11/22/2022]
Abstract
The recent discovery that some terrestrial arthropods can detect, use, and learn from weak electrical fields adds a new dimension to our understanding of how organisms explore and interact with their environments. For bees and spiders, the filiform mechanosensory systems enable this novel sensory modality by carrying electric charge and deflecting in response to electrical fields. This mode of information acquisition opens avenues for previously unrealised sensory dynamics and capabilities. In this paper, we study one such potential: the possibility for an arthropod to locate electrically charged objects. We begin by illustrating how electrostatic interactions between hairs and surrounding electrical fields enable the process of location detection. After which we examine three scenarios: (1) the determination of the location and magnitude of multiple point charges through a single observation, (2) the learning of electrical and mechanical sensor properties and the characteristics of an electrical field through several observations, (3) the possibility that an observer can infer their location and orientation in a fixed and known electrical field (akin to "stellar navigation"). To conclude, we discuss the potential of electroreception to endow an animal with thus far unappreciated sensory capabilities, such as the mapping of electrical environments. Electroreception by terrestrial arthropods offers a renewed understanding of the sensory processes carried out by filiform hairs, adding to aero-acoustic sensing and opening up the possibility of new emergent collective dynamics and information acquisition by distributed hair sensors.
Collapse
|
3
|
Mulder-Rosi J, Miller JP. ENCODING OF SMALL-SCALE AIR MOTION DYNAMICS IN THE CRICKET ACHETA DOMESTICUS. J Neurophysiol 2022; 127:1185-1197. [PMID: 35353628 PMCID: PMC9018005 DOI: 10.1152/jn.00042.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The cercal sensory system of the cricket mediates the detection, localization and identification of air current signals generated by predators, mates and competitors. This mechanosensory system has been used extensively for experimental and theoretical studies of sensory coding at the cellular and system levels. It is currently thought that sensory interneurons in the terminal abdominal ganglion extract information about the direction, velocity, and acceleration of the air currents in the animal's immediate environment, and project a coarse-coded representation of those parameters to higher centers. All feature detection is thought to be carried out in higher ganglia by more complex, specialized circuits. We present results that force a substantial revision of current hypotheses. Using multiple extracellular recordings and a special sensory stimulation device, we demonstrate that four well-studied interneurons in this system respond with high sensitivity and selectivity to complex dynamic multi-directional features of air currents which have a spatial scale smaller than the physical dimensions of the cerci. The INs showed much greater sensitivity for these features than for unidirectional bulk-flow stimuli used in previous studies. Thus, in addition to participating in the ensemble encoding of bulk air flow stimulus characteristics, these interneurons are capable of operating as feature detectors for naturalistic stimuli. In this sense, these interneurons are encoding and transmitting information about different aspects of their stimulus environment: they are multiplexing information. Major aspects of the stimulus-response specificity of these interneurons can be understood from the dendritic anatomy and connectivity with the sensory afferent map.
Collapse
Affiliation(s)
- Jonas Mulder-Rosi
- Deptartment of Microbiology and Immunology, Montana State University, Bozeman Montana, United States
| | - John P Miller
- Deptartment of Microbiology and Immunology, Montana State University, Bozeman Montana, United States
| |
Collapse
|
4
|
Palmer RA, Chenchiah IV, Robert D. The mechanics and interactions of electrically sensitive mechanoreceptive hair arrays of arthropods. J R Soc Interface 2022; 19:20220053. [PMID: 35317646 PMCID: PMC8941402 DOI: 10.1098/rsif.2022.0053] [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] [Indexed: 11/12/2022] Open
Abstract
Recent investigations highlight the possibility of electroreception within arthropods through charged mechanosensory hairs. This discovery raises questions about the influence of electrostatic interaction between hairs and surrounding electrical fields within this sensory modality. Here, we investigate these questions by studying electrostatic coupling in arrays of hairs. We establish the notion of sensitivity contours that indicate regions within which point charges deflect hairs beyond a given threshold. We then examine how the contour’s shape and size and the overall hair behaviour change in response to variations in the coupling between hairs. This investigation unveils synergistic behaviours whereby the sensitivity of hairs is enhanced or inhibited by neighbouring hairs. The hair spacing and ratio of a system’s electrical parameters to its mechanical parameters influence this behaviour. Our results indicate that electrostatic interaction between hairs leads to emergent sensory properties for biologically relevant parameter values. The analysis raises new questions around the impact of electrostatic interaction on the current understanding of sensory hair processes, such as acoustic sensing, unveiling new sensory capabilities within electroreception such as amplification of hair sensitivity and location detection of charges in the environment.
Collapse
Affiliation(s)
- Ryan A Palmer
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK.,School of Mathematics, University of Bristol, Fry Building, Woodland Road, Bristol BS8 1UG, UK
| | - Isaac V Chenchiah
- School of Mathematics, University of Bristol, Fry Building, Woodland Road, Bristol BS8 1UG, UK
| | - Daniel Robert
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| |
Collapse
|
5
|
Palmer RA, Chenchiah IV, Robert D. Analysis of aerodynamic and electrostatic sensing in mechanoreceptor arthropod hairs. J Theor Biol 2021; 530:110871. [PMID: 34411607 DOI: 10.1016/j.jtbi.2021.110871] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 06/29/2021] [Accepted: 08/11/2021] [Indexed: 11/29/2022]
Abstract
We study the mechanics of mechanoreceptor hairs in response to electro- and acousto-stimuli to expand the theory of tuning within filiform mechano-sensory systems and show the physical, biological and parametric feasibility of electroreception in comparison to aerodynamic sensing. We begin by analysing two well-known mechanosensory systems, the MeD1 spider trichobothria and the cricket cercal hair, offering a systematic appraisal of the physics of mechanosensory hair motion. Then we explore the biologically relevant parameter space of mechanoreceptor hairs by varying each oscillator parameter, thereby extending the theory to general arthropods. In doing so, we readily identify combinations of parameters for which a hair shows an enhanced or distinct response to either electric or aerodynamic stimuli. Overall, we find distinct behaviours in the two systems with novel insight provided through the parameter-space analysis. We show how the parameter space and balance of parameters therein of the resonant spider system are organised to produce a highly tuneable hair system through variation of hair length, whilst the broader parameter space of the non-resonant cricket system responds equally to a wider range of driving frequencies with increased capacity for high temporal resolution. From our analysis, we hypothesise the existence of two distinct types of mechanoreceptive system: the general system where hairs of all lengths are poised to detect both electro- and acousto- stimuli, and a stimuli-specific system where the sensitivity and specificity of the hairs to the different stimuli changes with length.
Collapse
Affiliation(s)
- Ryan A Palmer
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, United Kingdom; School of Mathematics, University of Bristol, Fry Building, Woodland Road, Bristol BS8 1UG, United Kingdom.
| | - Isaac V Chenchiah
- School of Mathematics, University of Bristol, Fry Building, Woodland Road, Bristol BS8 1UG, United Kingdom
| | - Daniel Robert
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, United Kingdom
| |
Collapse
|
6
|
Dalgaty T, Miller JP, Vianello E, Casas J. Bio-Inspired Architectures Substantially Reduce the Memory Requirements of Neural Network Models. Front Neurosci 2021; 15:612359. [PMID: 33708069 PMCID: PMC7940538 DOI: 10.3389/fnins.2021.612359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 02/02/2021] [Indexed: 11/30/2022] Open
Abstract
We propose a neural network model for the jumping escape response behavior observed in the cricket cercal sensory system. This sensory system processes low-intensity air currents in the animal's immediate environment generated by predators, competitors, and mates. Our model is inspired by decades of physiological and anatomical studies. We compare the performance of our model with a model derived through a universal approximation, or a generic deep learning, approach, and demonstrate that, to achieve the same performance, these models required between one and two orders of magnitude more parameters. Furthermore, since the architecture of the bio-inspired model is defined by a set of logical relations between neurons, we find that the model is open to interpretation and can be understood. This work demonstrates the potential of incorporating bio-inspired architectural motifs, which have evolved in animal nervous systems, into memory efficient neural network models.
Collapse
Affiliation(s)
| | - John P Miller
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, United States
| | | | - Jérôme Casas
- Insect Biology Research Institute IRBI, UMR CNRS 7261, Université de Tours, Tours, France
| |
Collapse
|
7
|
Tuttle LJ, Robinson HE, Takagi D, Strickler JR, Lenz PH, Hartline DK. Going with the flow: hydrodynamic cues trigger directed escapes from a stalking predator. J R Soc Interface 2019; 16:20180776. [PMID: 30958200 PMCID: PMC6408353 DOI: 10.1098/rsif.2018.0776] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 02/04/2019] [Indexed: 11/12/2022] Open
Abstract
In the coevolution of predator and prey, different and less well-understood rules for threat assessment apply to freely suspended organisms than to substrate-dwelling ones. Particularly vulnerable are small prey carried with the bulk movement of a surrounding fluid and thus deprived of sensory information within the bow waves of approaching predators. Some planktonic prey have solved this apparent problem, however. We quantified cues generated by the slow approach of larval clownfish ( Amphiprion ocellaris) that triggered a calanoid copepod ( Bestiolina similis) to escape before the fish could strike. To estimate water deformation around the copepod immediately preceding its jump, we represented the body of the fish as a rigid sphere in a hydrodynamic model that we parametrized with measurements of fish size, approach speed and distance to the copepod. Copepods of various developmental stages (CII-CVI) were sensitive to the water flow caused by the live predator, at deformation rates as low as 0.04 s-1. This rate is far lower than that predicted from experiments that used artificial predator-mimics. Additionally, copepods localized the source, with 87% of escapes directed away (greater than or equal to 90°) from the predator. Thus, copepods' survival in life-threatening situations relied on their detection of small nonlinear signals within an environment of locally linear deformation.
Collapse
Affiliation(s)
- Lillian J. Tuttle
- Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, University of Hawai′i at Mānoa, Honolulu, HI 96822, USA
| | - H. Eve Robinson
- Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, University of Hawai′i at Mānoa, Honolulu, HI 96822, USA
- Department of Biological Sciences, Humboldt State University, Arcata, CA 95521, USA
| | - Daisuke Takagi
- Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, University of Hawai′i at Mānoa, Honolulu, HI 96822, USA
- Department of Mathematics, University of Hawai′i at Mānoa, Honolulu, HI 96822, USA
| | - J. Rudi Strickler
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53204, USA
- University of Texas Marine Science Institute, Port Aransas, TX 78373, USA
| | - Petra H. Lenz
- Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, University of Hawai′i at Mānoa, Honolulu, HI 96822, USA
| | - Daniel K. Hartline
- Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, University of Hawai′i at Mānoa, Honolulu, HI 96822, USA
| |
Collapse
|
8
|
Seale M, Cummins C, Viola IM, Mastropaolo E, Nakayama N. Design principles of hair-like structures as biological machines. J R Soc Interface 2018; 15:20180206. [PMID: 29848593 PMCID: PMC6000178 DOI: 10.1098/rsif.2018.0206] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 05/08/2018] [Indexed: 12/02/2022] Open
Abstract
Hair-like structures are prevalent throughout biology and frequently act to sense or alter interactions with an organism's environment. The overall shape of a hair is simple: a long, filamentous object that protrudes from the surface of an organism. This basic design, however, can confer a wide range of functions, owing largely to the flexibility and large surface area that it usually possesses. From this simple structural basis, small changes in geometry, such as diameter, curvature and inter-hair spacing, can have considerable effects on mechanical properties, allowing functions such as mechanosensing, attachment, movement and protection. Here, we explore how passive features of hair-like structures, both individually and within arrays, enable diverse functions across biology. Understanding the relationships between form and function can provide biologists with an appreciation for the constraints and possibilities on hair-like structures. Additionally, such structures have already been used in biomimetic engineering with applications in sensing, water capture and adhesion. By examining hairs as a functional mechanical unit, geometry and arrangement can be rationally designed to generate new engineering devices and ideas.
Collapse
Affiliation(s)
- Madeleine Seale
- School of Biological Sciences, Institute of Molecular Plant Sciences, University of Edinburgh, Edinburgh, UK
- School of Engineering, Institute for Integrated Micro and Nano Systems, University of Edinburgh, Edinburgh, UK
- SynthSys Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, UK
| | - Cathal Cummins
- School of Biological Sciences, Institute of Molecular Plant Sciences, University of Edinburgh, Edinburgh, UK
- SynthSys Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, UK
- School of Engineering, Institute for Energy Systems, University of Edinburgh, Edinburgh, UK
| | - Ignazio Maria Viola
- School of Engineering, Institute for Energy Systems, University of Edinburgh, Edinburgh, UK
| | - Enrico Mastropaolo
- School of Engineering, Institute for Integrated Micro and Nano Systems, University of Edinburgh, Edinburgh, UK
| | - Naomi Nakayama
- School of Biological Sciences, Institute of Molecular Plant Sciences, University of Edinburgh, Edinburgh, UK
- SynthSys Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, UK
- Centre for Science at Extreme Conditions, University of Edinburgh, Edinburgh, UK
| |
Collapse
|
9
|
Müller R. Quantitative approaches to sensory information encoding by bat noseleaves and pinnae. CAN J ZOOL 2018. [DOI: 10.1139/cjz-2017-0117] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The biosonar systems of horseshoe bats (Rhinolophidae) and Old World round leaf-nosed bats (Hipposideridae) incorporate a pervasive dynamic at the interfaces for ultrasound emission (noseleaves) and reception (pinnae). Changes in the shapes of these structures alter the acoustic characteristics of the biosonar system and could hence influence the encoding of sensory information. The focus of the present work is on approaches that can be used to investigate the hypothesis that the interface dynamic effects sensory information encoding. Mutual information can be used as a metric to quantify the extent to which the different ultrasonic emission and reception characteristics (beampatterns) provide independent views of the environment. Two different quantitative approaches have been taken to evaluate the relationship between dynamically encoded additional sensory information and sensing performance in finding the direction of a biosonar target. The first approach is to determine an upper bound on the number of different directions that can be distinguished by virtue of distinct spectral signatures. The second approach is based on a lower bound (Cramér–Rao) on the variance of direction estimates. All these different metrics demonstrate that the peripheral dynamics seen in bats result in the encoding of additional sensory information that is suitable for enhancing biosonar performance.
Collapse
Affiliation(s)
- Rolf Müller
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, USA; Shandong University – Virginia Tech International Laboratory, Shandong University, Jinan, People’s Republic of China
- Department of Mechanical Engineering, Virginia Tech, Blacksburg, VA 24061, USA; Shandong University – Virginia Tech International Laboratory, Shandong University, Jinan, People’s Republic of China
| |
Collapse
|