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Gorko B, Siwanowicz I, Close K, Christoforou C, Hibbard KL, Kabra M, Lee A, Park JY, Li SY, Chen AB, Namiki S, Chen C, Tuthill JC, Bock DD, Rouault H, Branson K, Ihrke G, Huston SJ. Motor neurons generate pose-targeted movements via proprioceptive sculpting. Nature 2024; 628:596-603. [PMID: 38509371 DOI: 10.1038/s41586-024-07222-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 02/22/2024] [Indexed: 03/22/2024]
Abstract
Motor neurons are the final common pathway1 through which the brain controls movement of the body, forming the basic elements from which all movement is composed. Yet how a single motor neuron contributes to control during natural movement remains unclear. Here we anatomically and functionally characterize the individual roles of the motor neurons that control head movement in the fly, Drosophila melanogaster. Counterintuitively, we find that activity in a single motor neuron rotates the head in different directions, depending on the starting posture of the head, such that the head converges towards a pose determined by the identity of the stimulated motor neuron. A feedback model predicts that this convergent behaviour results from motor neuron drive interacting with proprioceptive feedback. We identify and genetically2 suppress a single class of proprioceptive neuron3 that changes the motor neuron-induced convergence as predicted by the feedback model. These data suggest a framework for how the brain controls movements: instead of directly generating movement in a given direction by activating a fixed set of motor neurons, the brain controls movements by adding bias to a continuing proprioceptive-motor loop.
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Affiliation(s)
- Benjamin Gorko
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA, USA
| | - Igor Siwanowicz
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Kari Close
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | | | - Karen L Hibbard
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Mayank Kabra
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Allen Lee
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Jin-Yong Park
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Si Ying Li
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, USA
| | - Alex B Chen
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Program in Neuroscience, Harvard Medical School, Boston, MA, USA
| | - Shigehiro Namiki
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Research Center for Advanced Science and Technology, University of Tokyo, Tokyo, Japan
| | - Chenghao Chen
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - John C Tuthill
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA
| | - Davi D Bock
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Department of Neurological Sciences, University of Vermont, Burlington, VT, USA
| | - Hervé Rouault
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Turing Centre for Living systems, Aix-Marseille University, Université de Toulon, CNRS, CPT (UMR 7332), Marseille, France
| | - Kristin Branson
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Gudrun Ihrke
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Stephen J Huston
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA.
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Egelhaaf M. Optic flow based spatial vision in insects. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023:10.1007/s00359-022-01610-w. [PMID: 36609568 DOI: 10.1007/s00359-022-01610-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 12/06/2022] [Accepted: 12/24/2022] [Indexed: 01/09/2023]
Abstract
The optic flow, i.e., the displacement of retinal images of objects in the environment induced by self-motion, is an important source of spatial information, especially for fast-flying insects. Spatial information over a wide range of distances, from the animal's immediate surroundings over several hundred metres to kilometres, is necessary for mediating behaviours, such as landing manoeuvres, collision avoidance in spatially complex environments, learning environmental object constellations and path integration in spatial navigation. To facilitate the processing of spatial information, the complexity of the optic flow is often reduced by active vision strategies. These result in translations and rotations being largely separated by a saccadic flight and gaze mode. Only the translational components of the optic flow contain spatial information. In the first step of optic flow processing, an array of local motion detectors provides a retinotopic spatial proximity map of the environment. This local motion information is then processed in parallel neural pathways in a task-specific manner and used to control the different components of spatial behaviour. A particular challenge here is that the distance information extracted from the optic flow does not represent the distances unambiguously, but these are scaled by the animal's speed of locomotion. Possible ways of coping with this ambiguity are discussed.
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Affiliation(s)
- Martin Egelhaaf
- Neurobiology and Center for Cognitive Interaction Technology (CITEC), Bielefeld University, Universitätsstraße 25, 33615, Bielefeld, Germany.
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3
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Active vision shapes and coordinates flight motor responses in flies. Proc Natl Acad Sci U S A 2020; 117:23085-23095. [PMID: 32873637 DOI: 10.1073/pnas.1920846117] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Animals use active sensing to respond to sensory inputs and guide future motor decisions. In flight, flies generate a pattern of head and body movements to stabilize gaze. How the brain relays visual information to control head and body movements and how active head movements influence downstream motor control remains elusive. Using a control theoretic framework, we studied the optomotor gaze stabilization reflex in tethered flight and quantified how head movements stabilize visual motion and shape wing steering efforts in fruit flies (Drosophila). By shaping visual inputs, head movements increased the gain of wing steering responses and coordination between stimulus and wings, pointing to a tight coupling between head and wing movements. Head movements followed the visual stimulus in as little as 10 ms-a delay similar to the human vestibulo-ocular reflex-whereas wing steering responses lagged by more than 40 ms. This timing difference suggests a temporal order in the flow of visual information such that the head filters visual information eliciting downstream wing steering responses. Head fixation significantly decreased the mechanical power generated by the flight motor by reducing wingbeat frequency and overall thrust. By simulating an elementary motion detector array, we show that head movements shift the effective visual input dynamic range onto the sensitivity optimum of the motion vision pathway. Taken together, our results reveal a transformative influence of active vision on flight motor responses in flies. Our work provides a framework for understanding how to coordinate moving sensors on a moving body.
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Steinbeck F, Adden A, Graham P. Connecting brain to behaviour: a role for general purpose steering circuits in insect orientation? J Exp Biol 2020; 223:223/5/jeb212332. [DOI: 10.1242/jeb.212332] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
ABSTRACT
The lateral accessory lobes (LALs), paired structures that are homologous among all insect species, have been well studied for their role in pheromone tracking in silkmoths and phonotaxis in crickets, where their outputs have been shown to correlate with observed motor activity. Further studies have shown more generally that the LALs are crucial both for an insect's ability to steer correctly and for organising the outputs of the descending pathways towards the motor centres. In this context, we propose a framework by which the LALs may be generally involved in generating steering commands across a variety of insects and behaviours. Across different behaviours, we see that the LAL is involved in generating two kinds of steering: (1) search behaviours and (2) targeted steering driven by direct sensory information. Search behaviours are generated when the current behaviourally relevant cues are not available, and a well-described LAL subnetwork produces activity which increases sampling of the environment. We propose that, when behaviourally relevant cues are available, the LALs may integrate orientation information from several sensory modalities, thus leading to a collective output for steering driven by those cues. These steering commands are then sent to the motor centres, and an additional efference copy is sent back to the orientation-computing areas. In summary, we have taken known aspects of the neurophysiology and function of the insect LALs and generated a speculative framework that suggests how LALs might be involved in steering control for a variety of complex real-world behaviours in insects.
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Affiliation(s)
- Fabian Steinbeck
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - Andrea Adden
- Department of Biology, Lund University, 223 62 Lund, Sweden
| | - Paul Graham
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
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5
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Binocular responsiveness of projection neurons of the praying mantis optic lobe in the frontal visual field. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2020; 206:165-181. [PMID: 32088748 PMCID: PMC7069917 DOI: 10.1007/s00359-020-01405-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 01/14/2020] [Accepted: 01/18/2020] [Indexed: 11/30/2022]
Abstract
Praying mantids are the only insects proven to have stereoscopic vision (stereopsis): the ability to perceive depth from the slightly shifted images seen by the two eyes. Recently, the first neurons likely to be involved in mantis stereopsis were described and a speculative neuronal circuit suggested. Here we further investigate classes of neurons in the lobula complex of the praying mantis brain and their tuning to stereoscopically-defined depth. We used sharp electrode recordings with tracer injections to identify visual projection neurons with input in the optic lobe and output in the central brain. In order to measure binocular response fields of the cells the animals watched a vertical bar stimulus in a 3D insect cinema during recordings. We describe the binocular tuning of 19 neurons projecting from the lobula complex and the medulla to central brain areas. The majority of neurons (12/19) were binocular and had receptive fields for both eyes that overlapped in the frontal region. Thus, these neurons could be involved in mantis stereopsis. We also find that neurons preferring different contrast polarity (bright vs dark) tend to be segregated in the mantis lobula complex, reminiscent of the segregation for small targets and widefield motion in mantids and other insects.
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Wei H, Kyung HY, Kim PJ, Desplan C. The diversity of lobula plate tangential cells (LPTCs) in the Drosophila motion vision system. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2019; 206:139-148. [PMID: 31709462 DOI: 10.1007/s00359-019-01380-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/29/2019] [Accepted: 11/05/2019] [Indexed: 12/15/2022]
Abstract
To navigate through the environment, animals rely on visual feedback to control their movements relative to their surroundings. In dipteran flies, visual feedback is provided by the wide-field motion-sensitive neurons in the visual system called lobula plate tangential cells (LPTCs). Understanding the role of LPTCs in fly behaviors can address many fundamental questions on how sensory circuits guide behaviors. The blowfly was estimated to have ~ 60 LPTCs, but only a few have been identified in Drosophila. We conducted a Gal4 driver screen and identified five LPTC subtypes in Drosophila, based on their morphological characteristics: LPTCs have large arborizations in the lobula plate and project to the central brain. We compared their morphologies to the blowfly LPTCs and named them after the most similar blowfly cells: CH, H1, H2, FD1 and FD3, and V1. We further characterized their pre- and post-synaptic organizations, as well as their neurotransmitter profiles. These anatomical features largely agree with the anatomy and function of their likely blowfly counterparts. Nevertheless, several anatomical details indicate the Drosophila LPTCs may have more complex functions. Our characterization of these five LPTCs in Drosophila will facilitate further functional studies to understand their roles in the visual circuits that instruct fly behaviors.
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Affiliation(s)
- Huayi Wei
- Department of Biology, New York University, New York, NY, USA
| | - Ha Young Kyung
- Department of Biology, New York University, New York, NY, USA
| | - Priscilla J Kim
- Department of Biology, New York University, New York, NY, USA
| | - Claude Desplan
- Department of Biology, New York University, New York, NY, USA.
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Kim AJ, Fenk LM, Lyu C, Maimon G. Quantitative Predictions Orchestrate Visual Signaling in Drosophila. Cell 2017; 168:280-294.e12. [PMID: 28065412 DOI: 10.1016/j.cell.2016.12.005] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 10/18/2016] [Accepted: 12/01/2016] [Indexed: 11/18/2022]
Abstract
Vision influences behavior, but ongoing behavior also modulates vision in animals ranging from insects to primates. The function and biophysical mechanisms of most such modulations remain unresolved. Here, we combine behavioral genetics, electrophysiology, and high-speed videography to advance a function for behavioral modulations of visual processing in Drosophila. We argue that a set of motion-sensitive visual neurons regulate gaze-stabilizing head movements. We describe how, during flight turns, Drosophila perform a set of head movements that require silencing their gaze-stability reflexes along the primary rotation axis of the turn. Consistent with this behavioral requirement, we find pervasive motor-related inputs to the visual neurons, which quantitatively silence their predicted visual responses to rotations around the relevant axis while preserving sensitivity around other axes. This work proposes a function for a behavioral modulation of visual processing and illustrates how the brain can remove one sensory signal from a circuit carrying multiple related signals.
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Affiliation(s)
- Anmo J Kim
- Laboratory of Integrative Brain Function, The Rockefeller University, New York, NY 10065, USA
| | - Lisa M Fenk
- Laboratory of Integrative Brain Function, The Rockefeller University, New York, NY 10065, USA
| | - Cheng Lyu
- Laboratory of Integrative Brain Function, The Rockefeller University, New York, NY 10065, USA
| | - Gaby Maimon
- Laboratory of Integrative Brain Function, The Rockefeller University, New York, NY 10065, USA.
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Kauer I, Borst A, Haag J. Complementary motion tuning in frontal nerve motor neurons of the blowfly. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2015; 201:411-26. [PMID: 25636734 DOI: 10.1007/s00359-015-0980-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 12/23/2014] [Accepted: 01/20/2015] [Indexed: 02/04/2023]
Abstract
Flies actively turn their head during flight to stabilize their gaze and reduce motion blur. This optomotor response is triggered by wide-field motion indicating a deviation from a desired flight path. We focus on the neuronal circuit that underlies this behavior in the blowfly Calliphora, studying the integration of optic flow in neck motor neurons that innervate muscles controlling head rotations. Frontal nerve motor neurons (FNMNs) have been described anatomically and recorded from extracellularly before. Here, we assign for the first time to five anatomical classes of FNMNs their visual motion tuning. We measured their responses to optic flow, as produced by rotations around particular body axes, recording intracellularly from single axons. Simultaneous injection of Neurobiotin allowed for the anatomical characterization of the recorded cells and revealed coupling patterns with neighboring neurons. The five FNMN classes can be divided into two groups that complement each other, regarding their preferred axes of rotation. The tuning matches the pulling planes of their innervated neck muscles, serving to rotate the head around its longitudinal axis. Anatomical and physiological findings demonstrate a synaptic connection between one FNMN and a well-described descending neuron, elucidating one important step from visual motion integration to neck motor output.
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Affiliation(s)
- Isabella Kauer
- Department of Circuits-Computation-Models, Max-Planck-Institute of Neurobiology, Am Klopferspitz 18, 82152, Martinsried, Germany,
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Kress D, Egelhaaf M. Impact of stride-coupled gaze shifts of walking blowflies on the neuronal representation of visual targets. Front Behav Neurosci 2014; 8:307. [PMID: 25309362 PMCID: PMC4164030 DOI: 10.3389/fnbeh.2014.00307] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 08/23/2014] [Indexed: 02/04/2023] Open
Abstract
During locomotion animals rely heavily on visual cues gained from the environment to guide their behavior. Examples are basic behaviors like collision avoidance or the approach to a goal. The saccadic gaze strategy of flying flies, which separates translational from rotational phases of locomotion, has been suggested to facilitate the extraction of environmental information, because only image flow evoked by translational self-motion contains relevant distance information about the surrounding world. In contrast to the translational phases of flight during which gaze direction is kept largely constant, walking flies experience continuous rotational image flow that is coupled to their stride-cycle. The consequences of these self-produced image shifts for the extraction of environmental information are still unclear. To assess the impact of stride-coupled image shifts on visual information processing, we performed electrophysiological recordings from the HSE cell, a motion sensitive wide-field neuron in the blowfly visual system. This cell has been concluded to play a key role in mediating optomotor behavior, self-motion estimation and spatial information processing. We used visual stimuli that were based on the visual input experienced by walking blowflies while approaching a black vertical bar. The response of HSE to these stimuli was dominated by periodic membrane potential fluctuations evoked by stride-coupled image shifts. Nevertheless, during the approach the cell's response contained information about the bar and its background. The response components evoked by the bar were larger than the responses to its background, especially during the last phase of the approach. However, as revealed by targeted modifications of the visual input during walking, the extraction of distance information on the basis of HSE responses is much impaired by stride-coupled retinal image shifts. Possible mechanisms that may cope with these stride-coupled responses are discussed.
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Affiliation(s)
- Daniel Kress
- Department of Neurobiology, Bielefeld UniversityBielefeld, Germany
- CITEC Center of Excellence Cognitive Interaction Technology, Bielefeld UniversityBielefeld, Germany
| | - Martin Egelhaaf
- Department of Neurobiology, Bielefeld UniversityBielefeld, Germany
- CITEC Center of Excellence Cognitive Interaction Technology, Bielefeld UniversityBielefeld, Germany
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Kress D, Egelhaaf M. Gaze characteristics of freely walking blowflies Calliphora vicina in a goal-directed task. ACTA ACUST UNITED AC 2014; 217:3209-20. [PMID: 25013104 DOI: 10.1242/jeb.097436] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In contrast to flying flies, walking flies experience relatively strong rotational gaze shifts, even during overall straight phases of locomotion. These gaze shifts are caused by the walking apparatus and modulated by the stride frequency. Accordingly, even during straight walking phases, the retinal image flow is composed of both translational and rotational optic flow, which might affect spatial vision, as well as fixation behavior. We addressed this issue for an orientation task where walking blowflies approached a black vertical bar. The visual stimulus was stationary, or either the bar or the background moved horizontally. The stride-coupled gaze shifts of flies walking toward the bar had similar amplitudes under all visual conditions tested. This finding indicates that these shifts are an inherent feature of walking, which are not even compensated during a visual goal fixation task. By contrast, approaching flies showed a frequent stop-and-go behavior that was affected by the stimulus conditions. As sustained image rotations may impair distance estimation during walking, we propose a hypothesis that explains how rotation-independent translatory image flow containing distance information can be determined. The algorithm proposed works without requiring differentiation at the behavioral level of the rotational and translational flow components. By contrast, disentangling both has been proposed to be necessary during flight. By comparing the retinal velocities of the edges of the goal, its rotational image motion component can be removed. Consequently, the expansion velocity of the goal and, thus, its proximity can be extracted, irrespective of distance-independent stride-coupled rotational image shifts.
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Affiliation(s)
- Daniel Kress
- Department of Neurobiology and CITEC Center of Excellence Cognitive Interaction Technology, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Martin Egelhaaf
- Department of Neurobiology and CITEC Center of Excellence Cognitive Interaction Technology, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
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Fox JL, Frye MA. Figure-ground discrimination behavior in Drosophila. II. Visual influences on head movement behavior. ACTA ACUST UNITED AC 2013; 217:570-9. [PMID: 24198264 PMCID: PMC3922834 DOI: 10.1242/jeb.080192] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Visual identification of small moving targets is a challenge for all moving animals. Their own motion generates displacement of the visual surroundings, inducing wide-field optic flow across the retina. Wide-field optic flow is used to sense perturbations in the flight course. Both ego-motion and corrective optomotor responses confound any attempt to track a salient target moving independently of the visual surroundings. What are the strategies that flying animals use to discriminate small-field figure motion from superimposed wide-field background motion? We examined how fruit flies adjust their gaze in response to a compound visual stimulus comprising a small moving figure against an independently moving wide-field ground, which they do by re-orienting their head or their flight trajectory. We found that fixing the head in place impairs object fixation in the presence of ground motion, and that head movements are necessary for stabilizing wing steering responses to wide-field ground motion when a figure is present. When a figure is moving relative to a moving ground, wing steering responses follow components of both the figure and ground trajectories, but head movements follow only the ground motion. To our knowledge, this is the first demonstration that wing responses can be uncoupled from head responses and that the two follow distinct trajectories in the case of simultaneous figure and ground motion. These results suggest that whereas figure tracking by wing kinematics is independent of head movements, head movements are important for stabilizing ground motion during active figure tracking.
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Affiliation(s)
- Jessica L Fox
- Howard Hughes Medical Institute and Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA 90095-7239, USA
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Kanzaki R, Minegishi R, Namiki S, Ando N. Insect-machine hybrid system for understanding and evaluating sensory-motor control by sex pheromone in Bombyx mori. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2013; 199:1037-52. [PMID: 23749329 DOI: 10.1007/s00359-013-0832-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 05/21/2013] [Accepted: 05/25/2013] [Indexed: 11/25/2022]
Abstract
To elucidate the dynamic information processing in a brain underlying adaptive behavior, it is necessary to understand the behavior and corresponding neural activities. This requires animals which have clear relationships between behavior and corresponding neural activities. Insects are precisely such animals and one of the adaptive behaviors of insects is high-accuracy odor source orientation. The most direct way to know the relationships between neural activity and behavior is by recording neural activities in a brain from freely behaving insects. There is also a method to give stimuli mimicking the natural environment to tethered insects allowing insects to walk or fly at the same position. In addition to these methods an 'insect-machine hybrid system' is proposed, which is another experimental system meeting the conditions necessary for approaching the dynamic processing in the brain of insects for generating adaptive behavior. This insect-machine hybrid system is an experimental system which has a mobile robot as its body. The robot is controlled by the insect through its behavior or the neural activities recorded from the brain. As we can arbitrarily control the motor output of the robot, we can intervene at the relationship between the insect and the environmental conditions.
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Affiliation(s)
- Ryohei Kanzaki
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Meguro-ku, Tokyo, 153-8904, Japan,
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Warzecha AK, Rosner R, Grewe J. Impact and sources of neuronal variability in the fly's motion vision pathway. ACTA ACUST UNITED AC 2012. [PMID: 23178476 DOI: 10.1016/j.jphysparis.2012.10.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Nervous systems encode information about dynamically changing sensory input by changes in neuronal activity. Neuronal activity changes, however, also arise from noise sources within and outside the nervous system or from changes of the animal's behavioral state. The resulting variability of neuronal responses in representing sensory stimuli limits the reliability with which animals can respond to stimuli and may thus even affect the chances for survival in certain situations. Relevant sources of noise arising at different stages along the motion vision pathway have been investigated from the sensory input to the initiation of behavioral reactions. Here, we concentrate on the reliability of processing visual motion information in flies. Flies rely on visual motion information to guide their locomotion. They are among the best established model systems for the processing of visual motion information allowing us to bridge the gap between behavioral performance and underlying neuronal computations. It has been possible to directly assess the consequences of noise at major stages of the fly's visual motion processing system on the reliability of neuronal signals. Responses of motion sensitive neurons and their variability have been related to optomotor movements as indicators for the overall performance of visual motion computation. We address whether and how noise already inherent in the stimulus, e.g. photon noise for the visual system, influences later processing stages and to what extent variability at the output level of the sensory system limits behavioral performance. Recent advances in circuit analysis and the progress in monitoring neuronal activity in behaving animals should now be applied to understand how the animal meets the requirements of fast and reliable manoeuvres in naturalistic situations.
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Affiliation(s)
| | - Ronny Rosner
- Tierphysiologie, Philipps-Universität Marburg, 35032 Marburg, Germany
| | - Jan Grewe
- Dept. Biology II, Ludwig-Maximilians Univ., 82152 Martinsried, Germany
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