1
|
Currier TA, Pang MM, Clandinin TR. Visual processing in the fly, from photoreceptors to behavior. Genetics 2023; 224:iyad064. [PMID: 37128740 PMCID: PMC10213501 DOI: 10.1093/genetics/iyad064] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 03/22/2023] [Indexed: 05/03/2023] Open
Abstract
Originally a genetic model organism, the experimental use of Drosophila melanogaster has grown to include quantitative behavioral analyses, sophisticated perturbations of neuronal function, and detailed sensory physiology. A highlight of these developments can be seen in the context of vision, where pioneering studies have uncovered fundamental and generalizable principles of sensory processing. Here we begin with an overview of vision-guided behaviors and common methods for probing visual circuits. We then outline the anatomy and physiology of brain regions involved in visual processing, beginning at the sensory periphery and ending with descending motor control. Areas of focus include contrast and motion detection in the optic lobe, circuits for visual feature selectivity, computations in support of spatial navigation, and contextual associative learning. Finally, we look to the future of fly visual neuroscience and discuss promising topics for further study.
Collapse
Affiliation(s)
- Timothy A Currier
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Michelle M Pang
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Thomas R Clandinin
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| |
Collapse
|
2
|
Fenk LM, Avritzer SC, Weisman JL, Nair A, Randt LD, Mohren TL, Siwanowicz I, Maimon G. Muscles that move the retina augment compound eye vision in Drosophila. Nature 2022; 612:116-122. [PMID: 36289333 PMCID: PMC10103069 DOI: 10.1038/s41586-022-05317-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 09/02/2022] [Indexed: 12/15/2022]
Abstract
Most animals have compound eyes, with tens to thousands of lenses attached rigidly to the exoskeleton. A natural assumption is that all of these species must resort to moving either their head or their body to actively change their visual input. However, classic anatomy has revealed that flies have muscles poised to move their retinas under the stable lenses of each compound eye1-3. Here we show that Drosophila use their retinal muscles to smoothly track visual motion, which helps to stabilize the retinal image, and also to perform small saccades when viewing a stationary scene. We show that when the retina moves, visual receptive fields shift accordingly, and that even the smallest retinal saccades activate visual neurons. Using a head-fixed behavioural paradigm, we find that Drosophila perform binocular, vergence movements of their retinas-which could enhance depth perception-when crossing gaps, and impairing the physiology of retinal motor neurons alters gap-crossing trajectories during free behaviour. That flies evolved an ability to actuate their retinas suggests that moving the eye independently of the head is broadly paramount for animals. The similarities of smooth and saccadic movements of the Drosophila retina and the vertebrate eye highlight a notable example of convergent evolution.
Collapse
Affiliation(s)
- Lisa M Fenk
- Laboratory of Integrative Brain Function and Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA.
- Active Sensing, Max Planck Institute for Biological Intelligence (in foundation), Martinsried, Germany.
| | - Sofia C Avritzer
- Laboratory of Integrative Brain Function and Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Jazz L Weisman
- Laboratory of Integrative Brain Function and Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Aditya Nair
- Laboratory of Integrative Brain Function and Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Lucas D Randt
- Active Sensing, Max Planck Institute for Biological Intelligence (in foundation), Martinsried, Germany
| | - Thomas L Mohren
- Laboratory of Integrative Brain Function and Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Igor Siwanowicz
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Gaby Maimon
- Laboratory of Integrative Brain Function and Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA.
| |
Collapse
|
3
|
Ryu L, Kim SY, Kim AJ. From Photons to Behaviors: Neural Implementations of Visual Behaviors in Drosophila. Front Neurosci 2022; 16:883640. [PMID: 35600623 PMCID: PMC9115102 DOI: 10.3389/fnins.2022.883640] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 03/28/2022] [Indexed: 11/17/2022] Open
Abstract
Neural implementations of visual behaviors in Drosophila have been dissected intensively in the past couple of decades. The availability of premiere genetic toolkits, behavioral assays in tethered or freely moving conditions, and advances in connectomics have permitted the understanding of the physiological and anatomical details of the nervous system underlying complex visual behaviors. In this review, we describe recent advances on how various features of a visual scene are detected by the Drosophila visual system and how the neural circuits process these signals and elicit an appropriate behavioral response. Special emphasis was laid on the neural circuits that detect visual features such as brightness, color, local motion, optic flow, and translating or approaching visual objects, which would be important for behaviors such as phototaxis, optomotor response, attraction (or aversion) to moving objects, navigation, and visual learning. This review offers an integrative framework for how the fly brain detects visual features and orchestrates an appropriate behavioral response.
Collapse
Affiliation(s)
- Leesun Ryu
- Department of Electronic Engineering, Hanyang University, Seoul, South Korea
| | - Sung Yong Kim
- Department of Electronic Engineering, Hanyang University, Seoul, South Korea
| | - Anmo J. Kim
- Department of Electronic Engineering, Hanyang University, Seoul, South Korea
- Department of Biomedical Engineering, Hanyang University, Seoul, South Korea
| |
Collapse
|
4
|
Hulse BK, Haberkern H, Franconville R, Turner-Evans DB, Takemura SY, Wolff T, Noorman M, Dreher M, Dan C, Parekh R, Hermundstad AM, Rubin GM, Jayaraman V. A connectome of the Drosophila central complex reveals network motifs suitable for flexible navigation and context-dependent action selection. eLife 2021; 10:66039. [PMID: 34696823 PMCID: PMC9477501 DOI: 10.7554/elife.66039] [Citation(s) in RCA: 122] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 09/07/2021] [Indexed: 11/13/2022] Open
Abstract
Flexible behaviors over long timescales are thought to engage recurrent neural networks in deep brain regions, which are experimentally challenging to study. In insects, recurrent circuit dynamics in a brain region called the central complex (CX) enable directed locomotion, sleep, and context- and experience-dependent spatial navigation. We describe the first complete electron-microscopy-based connectome of the Drosophila CX, including all its neurons and circuits at synaptic resolution. We identified new CX neuron types, novel sensory and motor pathways, and network motifs that likely enable the CX to extract the fly's head-direction, maintain it with attractor dynamics, and combine it with other sensorimotor information to perform vector-based navigational computations. We also identified numerous pathways that may facilitate the selection of CX-driven behavioral patterns by context and internal state. The CX connectome provides a comprehensive blueprint necessary for a detailed understanding of network dynamics underlying sleep, flexible navigation, and state-dependent action selection.
Collapse
Affiliation(s)
- Brad K Hulse
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Hannah Haberkern
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Romain Franconville
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | | | | | - Tanya Wolff
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Marcella Noorman
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Marisa Dreher
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Chuntao Dan
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Ruchi Parekh
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | | | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Vivek Jayaraman
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| |
Collapse
|
5
|
|
6
|
Abstract
One in three epilepsy cases is drug resistant, and seizures often begin in infancy, when they are life-threatening and when therapeutic options are highly limited. An important tool for prioritizing and validating genes associated with epileptic conditions, which is suitable for large-scale screening, is disease modeling in Drosophila. Approximately two-thirds of disease genes are conserved in Drosophila, and gene-specific fly models exhibit behavioral changes that are related to symptoms of epilepsy. Models are based on behavior readouts, seizure-like attacks and paralysis following stimulation, and neuronal, cell-biological readouts that are in the majority based on changes in nerve cell activity or morphology. In this review, we focus on behavioral phenotypes. Importantly, Drosophila modeling is independent of, and complementary to, other approaches that are computational and based on systems analysis. The large number of known epilepsy-associated gene variants indicates a need for efficient research strategies. We will discuss the status quo of epilepsy disease modelling in Drosophila and describe promising steps towards the development of new drugs to reduce seizure rates and alleviate other epileptic symptoms.
Collapse
Affiliation(s)
- Paul Lasko
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, Netherlands
- Department of Biology, McGill University, Montréal, Québec, Canada
| | - Kevin Lüthy
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, Netherlands
| |
Collapse
|
7
|
Cheong HS, Siwanowicz I, Card GM. Multi-regional circuits underlying visually guided decision-making in Drosophila. Curr Opin Neurobiol 2020; 65:77-87. [PMID: 33217639 DOI: 10.1016/j.conb.2020.10.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/30/2020] [Accepted: 10/02/2020] [Indexed: 12/26/2022]
Abstract
Visually guided decision-making requires integration of information from distributed brain areas, necessitating a brain-wide approach to examine its neural mechanisms. New tools in Drosophila melanogaster enable circuits spanning the brain to be charted with single cell-type resolution. Here, we highlight recent advances uncovering the computations and circuits that transform and integrate visual information across the brain to make behavioral choices. Visual information flows from the optic lobes to three primary central brain regions: a sensorimotor mapping area and two 'higher' centers for memory or spatial orientation. Rapid decision-making during predator evasion emerges from the spike timing dynamics in parallel sensorimotor cascades. Goal-directed decisions may occur through memory, navigation and valence processing in the central complex and mushroom bodies.
Collapse
Affiliation(s)
- Han Sj Cheong
- HHMI Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, United States
| | - Igor Siwanowicz
- HHMI Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, United States
| | - Gwyneth M Card
- HHMI Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, United States.
| |
Collapse
|
8
|
Luan H, Diao F, Scott RL, White BH. The Drosophila Split Gal4 System for Neural Circuit Mapping. Front Neural Circuits 2020; 14:603397. [PMID: 33240047 PMCID: PMC7680822 DOI: 10.3389/fncir.2020.603397] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 10/06/2020] [Indexed: 12/22/2022] Open
Abstract
The diversity and dense interconnectivity of cells in the nervous system present a huge challenge to understanding how brains work. Recent progress toward such understanding, however, has been fuelled by the development of techniques for selectively monitoring and manipulating the function of distinct cell types-and even individual neurons-in the brains of living animals. These sophisticated techniques are fundamentally genetic and have found their greatest application in genetic model organisms, such as the fruit fly Drosophila melanogaster. Drosophila combines genetic tractability with a compact, but cell-type rich, nervous system and has been the incubator for a variety of methods of neuronal targeting. One such method, called Split Gal4, is playing an increasingly important role in mapping neural circuits in the fly. In conjunction with functional perturbations and behavioral screens, Split Gal4 has been used to characterize circuits governing such activities as grooming, aggression, and mating. It has also been leveraged to comprehensively map and functionally characterize cells composing important brain regions, such as the central complex, lateral horn, and the mushroom body-the latter being the insect seat of learning and memory. With connectomics data emerging for both the larval and adult brains of Drosophila, Split Gal4 is also poised to play an important role in characterizing neurons of interest based on their connectivity. We summarize the history and current state of the Split Gal4 method and indicate promising areas for further development or future application.
Collapse
Affiliation(s)
| | | | | | - Benjamin H. White
- Laboratory of Molecular Biology, National Institute of Mental Health, NIH, Bethesda, MD, United States
| |
Collapse
|
9
|
Jovanic T. Studying neural circuits of decision-making in Drosophila larva. J Neurogenet 2020; 34:162-170. [PMID: 32054384 DOI: 10.1080/01677063.2020.1719407] [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: 10/25/2022]
Abstract
To study neural circuits underlying decisions, the model organism used for that purpose has to be simple enough to be able to dissect the circuitry neuron by neuron across the nervous system and in the same time complex enough to be able to perform different types of decisions. Here, I lay out the case: (1) that Drosophila larva is an advantageous model system that balances well these two requirements and (2) the insights gained from this model, assuming that circuit principles may be shared across species, can be used to advance our knowledge of neural circuit implementation of decision-making in general, including in more complex brains.
Collapse
Affiliation(s)
- Tihana Jovanic
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris Saclay, Gif-sur-Yvette, France.,Decision and Bayesian Computation, UMR 3571 Neuroscience Department & USR 3756 (C3BI/DBC), Institut Pasteur & CNRS, Paris, France
| |
Collapse
|
10
|
Tanimoto H. Bodily Awareness: How Flies Learn Their Own Body Size. Curr Biol 2019; 29:R572-R574. [PMID: 31211976 DOI: 10.1016/j.cub.2019.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Animals need to perceive their own body size to apprehend their relationship to the environment. A new study shows that the fruit fly Drosophila acquires the requisite information on its body size from visual feedback during walking, and has further identified a subset of neurons responsible for maintenance of body-size memory.
Collapse
Affiliation(s)
- Hiromu Tanimoto
- Graduate School of Life Sciences, Tohoku University, Katahira 2-1-1, 980-8577 Sendai, Japan.
| |
Collapse
|
11
|
Longden KD, Wicklein M, Hardcastle BJ, Huston SJ, Krapp HG. Spike Burst Coding of Translatory Optic Flow and Depth from Motion in the Fly Visual System. Curr Biol 2017; 27:3225-3236.e3. [PMID: 29056452 DOI: 10.1016/j.cub.2017.09.044] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 08/11/2017] [Accepted: 09/20/2017] [Indexed: 11/19/2022]
Abstract
Many animals use the visual motion generated by traveling straight-the translatory optic flow-to successfully navigate obstacles: near objects appear larger and to move more quickly than distant objects. Flies are expert at navigating cluttered environments, and while their visual processing of rotatory optic flow is understood in exquisite detail, how they process translatory optic flow remains a mystery. We present novel cell types that have local motion receptive fields matched to translation self-motion, the vertical translation (VT) cells. One of these, the VT1 cell, encodes self-motion in the forward-sideslip direction and fires action potentials in spike bursts as well as single spikes. We show that the spike burst coding is size and speed-tuned and is selectively modulated by motion parallax-the relative motion experienced during translation. These properties are spatially organized, so that the cell is most excited by clutter rather than isolated objects. When the fly is presented with a simulation of flying past an elevated object, the spike burst activity is modulated by the height of the object, and the rate of single spikes is unaffected. When the moving object alone is experienced, the cell is weakly driven. Meanwhile, the VT2-3 cells have motion receptive fields matched to the lift axis. In conjunction with previously described horizontal cells, the VT cells have properties well suited to the visual navigation of clutter and to encode the fly's movements along near cardinal axes of thrust, lift, and forward sideslip.
Collapse
Affiliation(s)
- Kit D Longden
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK.
| | - Martina Wicklein
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Ben J Hardcastle
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Stephen J Huston
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Holger G Krapp
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| |
Collapse
|
12
|
Robie AA, Hirokawa J, Edwards AW, Umayam LA, Lee A, Phillips ML, Card GM, Korff W, Rubin GM, Simpson JH, Reiser MB, Branson K. Mapping the Neural Substrates of Behavior. Cell 2017; 170:393-406.e28. [PMID: 28709004 DOI: 10.1016/j.cell.2017.06.032] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 05/01/2017] [Accepted: 06/19/2017] [Indexed: 11/20/2022]
Abstract
Assigning behavioral functions to neural structures has long been a central goal in neuroscience and is a necessary first step toward a circuit-level understanding of how the brain generates behavior. Here, we map the neural substrates of locomotion and social behaviors for Drosophila melanogaster using automated machine-vision and machine-learning techniques. From videos of 400,000 flies, we quantified the behavioral effects of activating 2,204 genetically targeted populations of neurons. We combined a novel quantification of anatomy with our behavioral analysis to create brain-behavior correlation maps, which are shared as browsable web pages and interactive software. Based on these maps, we generated hypotheses of regions of the brain causally related to sensory processing, locomotor control, courtship, aggression, and sleep. Our maps directly specify genetic tools to target these regions, which we used to identify a small population of neurons with a role in the control of walking.
Collapse
Affiliation(s)
- Alice A Robie
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Jonathan Hirokawa
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA; Laboratory of Integrative Brain Function, The Rockefeller University, New York, NY, USA
| | - Austin W Edwards
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Lowell A Umayam
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Allen Lee
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Mary L Phillips
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA; Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Gwyneth M Card
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Wyatt Korff
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Julie H Simpson
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA; Department of Molecular, Cellular, and Developmental Biology, UC Santa Barbara, Santa Barbara, CA, USA
| | - Michael B Reiser
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Kristin Branson
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
| |
Collapse
|