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Althaus V, Exner G, von Hadeln J, Homberg U, Rosner R. Anatomical organization of the cerebrum of the praying mantis Hierodula membranacea. J Comp Neurol 2024; 532:e25607. [PMID: 38501930 DOI: 10.1002/cne.25607] [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: 10/06/2023] [Revised: 02/22/2024] [Accepted: 03/07/2024] [Indexed: 03/20/2024]
Abstract
Many predatory animals, such as the praying mantis, use vision for prey detection and capture. Mantises are known in particular for their capability to estimate distances to prey by stereoscopic vision. While the initial visual processing centers have been extensively documented, we lack knowledge on the architecture of central brain regions, pivotal for sensory motor transformation and higher brain functions. To close this gap, we provide a three-dimensional (3D) reconstruction of the central brain of the Asian mantis, Hierodula membranacea. The atlas facilitates in-depth analysis of neuron ramification regions and aides in elucidating potential neuronal pathways. We integrated seven 3D-reconstructed visual interneurons into the atlas. In total, 42 distinct neuropils of the cerebrum were reconstructed based on synapsin-immunolabeled whole-mount brains. Backfills from the antenna and maxillary palps, as well as immunolabeling of γ-aminobutyric acid (GABA) and tyrosine hydroxylase (TH), further substantiate the identification and boundaries of brain areas. The composition and internal organization of the neuropils were compared to the anatomical organization of the brain of the fruit fly (Drosophila melanogaster) and the two available brain atlases of Polyneoptera-the desert locust (Schistocerca gregaria) and the Madeira cockroach (Rhyparobia maderae). This study paves the way for detailed analyses of neuronal circuitry and promotes cross-species brain comparisons. We discuss differences in brain organization between holometabolous and polyneopteran insects. Identification of ramification sites of the visual neurons integrated into the atlas supports previous claims about homologous structures in the optic lobes of flies and mantises.
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Affiliation(s)
- Vanessa Althaus
- Department of Biology, Animal Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Gesa Exner
- Department of Biology, Animal Physiology, Philipps-University of Marburg, Marburg, Germany
- Center for Mind Brain and Behavior (CMBB), University of Marburg and Justus Liebig University of Giessen, Marburg, Germany
| | - Joss von Hadeln
- Department of Biology, Animal Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Uwe Homberg
- Department of Biology, Animal Physiology, Philipps-University of Marburg, Marburg, Germany
- Center for Mind Brain and Behavior (CMBB), University of Marburg and Justus Liebig University of Giessen, Marburg, Germany
| | - Ronny Rosner
- Department of Biology, Animal Physiology, Philipps-University of Marburg, Marburg, Germany
- Department of Biology, Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University of Mainz, Mainz, Germany
- Biosciences Institute, Henry Wellcome Building for Neuroecology, Newcastle University, Framlington Place, Newcastle upon Tyne, UK
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2
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Beetz MJ, El Jundi B. The neurobiology of the Monarch butterfly compass. CURRENT OPINION IN INSECT SCIENCE 2023; 60:101109. [PMID: 37660836 DOI: 10.1016/j.cois.2023.101109] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/17/2023] [Accepted: 08/28/2023] [Indexed: 09/05/2023]
Abstract
Monarch butterflies (Danaus plexippus) have become a superb model system to unravel how the tiny insect brain controls an impressive navigation behavior, such as long-distance migration. Moreover, the ability to compare the neural substrate between migratory and nonmigratory Monarch butterflies provides us with an attractive model to specifically study how the insect brain is adapted for migration. We here review our current progress on the neural substrate of spatial orientation in Monarch butterflies and how their spectacular annual migration might be controlled by their brain. We also discuss open research questions, the answers to which will provide important missing pieces to obtain a full picture of insect migration - from the perception of orientation cues to the neural control of migration.
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Affiliation(s)
- M Jerome Beetz
- Zoology II, Biocenter, University of Würzburg, Würzburg, Germany
| | - Basil El Jundi
- Animal Physiology, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway.
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3
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Jahn S, Althaus V, Heckmann J, Janning M, Seip AK, Takahashi N, Grigoriev C, Kolano J, Homberg U. Neuroarchitecture of the central complex in the Madeira cockroach Rhyparobia maderae: Pontine and columnar neuronal cell types. J Comp Neurol 2023; 531:1689-1714. [PMID: 37608556 DOI: 10.1002/cne.25535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 07/27/2023] [Accepted: 08/03/2023] [Indexed: 08/24/2023]
Abstract
Insects have evolved remarkable abilities to navigate over short distances and during long-range seasonal migrations. The central complex (CX) is a navigation center in the insect brain that controls spatial orientation and directed locomotion. It is composed of the protocerebral bridge (PB), the upper (CBU) and lower (CBL) division of the central body, and a pair of noduli. While most of its functional organization and involvement in head-direction coding has been obtained from work on flies, bees, and locusts that largely rely on vision for navigation, little contribution has been provided by work on nocturnal species. To close this gap, we have investigated the columnar organization of the CX in the cockroach Rhyparobia maderae. Rhyparobia maderae is a highly agile nocturnal insect that relies largely but not exclusively on antennal information for navigation. A particular feature of the cockroach CX is an organization of the CBU and CBL into interleaved series of eight and nine columns. Single-cell tracer injections combined with imaging and 3D analysis revealed five systems of pontine neurons connecting columns along the vertical and horizontal axis and 18 systems of columnar neurons with topographically organized projection patterns. Among these are six types of neurons with no correspondence in other species. Many neurons send processes into the anterior lip, a brain area highly reduced in bees and unknown in flies. While sharing many features with the CX in other species, the cockroach CX shows some unique attributes that may be related to the ecological niche of this insect.
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Affiliation(s)
- Stefanie Jahn
- Animal Physiology, Department of Biology, Philipps University of Marburg, Marburg, Germany
| | - Vanessa Althaus
- Animal Physiology, Department of Biology, Philipps University of Marburg, Marburg, Germany
| | - Jannik Heckmann
- Animal Physiology, Department of Biology, Philipps University of Marburg, Marburg, Germany
| | - Mona Janning
- Animal Physiology, Department of Biology, Philipps University of Marburg, Marburg, Germany
| | - Ann-Katrin Seip
- Animal Physiology, Department of Biology, Philipps University of Marburg, Marburg, Germany
| | - Naomi Takahashi
- Animal Physiology, Department of Biology, Philipps University of Marburg, Marburg, Germany
| | - Clara Grigoriev
- Animal Physiology, Department of Biology, Philipps University of Marburg, Marburg, Germany
| | - Juliana Kolano
- Animal Physiology, Department of Biology, Philipps University of Marburg, Marburg, Germany
| | - Uwe Homberg
- Animal Physiology, Department of Biology, Philipps University of Marburg, Marburg, Germany
- Center for Mind Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Marburg, Germany
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4
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Wernet MF, Roberts NW, Belušič G. Non-celestial polarization vision in arthropods. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023; 209:855-857. [PMID: 37874372 DOI: 10.1007/s00359-023-01679-x] [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: 09/24/2023] [Revised: 10/05/2023] [Accepted: 10/09/2023] [Indexed: 10/25/2023]
Abstract
Most insects can detect the pattern of polarized light in the sky with the dorsal rim area in their compound eyes and use this visual information to navigate in their environment by means of 'celestial' polarization vision. 'Non-celestial polarization vision', in contrast, refers to the ability of arthropods to analyze polarized light by means of the 'main' retina, excluding the dorsal rim area. The ability of using the main retina for polarization vision has been attracting sporadic, but steady attention during the last decade. This special issue of the Journal of Comparative Physiology A presents recent developments with a collection of seven original research articles, addressing different aspects of non-celestial polarization vision in crustaceans and insects. The contributions cover different sources of linearly polarized light in nature, the underlying retinal and neural mechanisms of object detection using polarization vision and the behavioral responses of arthropods to polarized reflections from water.
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Affiliation(s)
- Mathias F Wernet
- Division of Neurobiology, Institute of Biology, Fachbereich Biologie, Freie Universität Berlin, Chemie and PharmazieKönigin-Luise Strasse 1-3, 14195, Berlin, Germany
| | - Nicholas W Roberts
- Ecology of Vision Group, School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, UK
| | - Gregor Belušič
- Biotechnical Faculty, Department of Biology, University of Ljubljana, Večna Pot 111, 1000, Ljubljana, Slovenia.
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5
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Homberg U, Kirchner M, Kowalewski K, Pitz V, Kinoshita M, Kern M, Seyfarth J. Comparative morphology of serotonin-immunoreactive neurons innervating the central complex in the brain of dicondylian insects. J Comp Neurol 2023. [PMID: 37478205 DOI: 10.1002/cne.25529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 06/28/2023] [Accepted: 07/08/2023] [Indexed: 07/23/2023]
Abstract
Serotonin (5-hydroxytryptamine) acts as a widespread neuromodulator in the nervous system of vertebrates and invertebrates. In insects, it promotes feeding, enhances olfactory sensitivity, modulates aggressive behavior, and, in the central complex of Drosophila, serves a role in sleep homeostasis. In addition to a role in sleep-wake regulation, the central complex has a prominent role in spatial orientation, goal-directed locomotion, and navigation vector memory. To further understand the role of serotonergic signaling in this brain area, we analyzed the distribution and identity of serotonin-immunoreactive neurons across a wide range of insect species. While one bilateral pair of tangential neurons innervating the central body was present in all species studied, a second type was labeled in all neopterans but not in dragonflies and firebrats. Both cell types show conserved major fiber trajectories but taxon-specific differences in dendritic targets outside the central body and axonal terminals in the central body, noduli, and lateral accessory lobes. In addition, numerous tangential neurons of the protocerebral bridge were labeled in all studied polyneopteran species except for Phasmatodea, but not in Holometabola. Lepidoptera and Diptera showed additional labeling of two bilateral pairs of neurons of a third type. The presence of serotonin in systems of columnar neurons apparently evolved independently in dragonflies and desert locusts. The data suggest distinct evolutionary changes in the composition of serotonin-immunolabeled neurons of the central complex and provides a promising basis for a phylogenetic study in a wider range of arthropod species.
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Affiliation(s)
- Uwe Homberg
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
- Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Marburg, Germany
| | - Michelle Kirchner
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
| | - Kevin Kowalewski
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
| | - Vanessa Pitz
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
| | - Michiyo Kinoshita
- Laboratory of Neuroethology, SOKENDAI, The Graduate University for Advanced Studies, Hayama, Japan
| | - Martina Kern
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
| | - Jutta Seyfarth
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
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6
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Kandimalla P, Omoto JJ, Hong EJ, Hartenstein V. Lineages to circuits: the developmental and evolutionary architecture of information channels into the central complex. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023; 209:679-720. [PMID: 36932234 PMCID: PMC10354165 DOI: 10.1007/s00359-023-01616-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 01/27/2023] [Accepted: 01/28/2023] [Indexed: 03/19/2023]
Abstract
The representation and integration of internal and external cues is crucial for any organism to execute appropriate behaviors. In insects, a highly conserved region of the brain, the central complex (CX), functions in the representation of spatial information and behavioral states, as well as the transformation of this information into desired navigational commands. How does this relatively invariant structure enable the incorporation of information from the diversity of anatomical, behavioral, and ecological niches occupied by insects? Here, we examine the input channels to the CX in the context of their development and evolution. Insect brains develop from ~ 100 neuroblasts per hemisphere that divide systematically to form "lineages" of sister neurons, that project to their target neuropils along anatomically characteristic tracts. Overlaying this developmental tract information onto the recently generated Drosophila "hemibrain" connectome and integrating this information with the anatomical and physiological recording of neurons in other species, we observe neuropil and lineage-specific innervation, connectivity, and activity profiles in CX input channels. We posit that the proliferative potential of neuroblasts and the lineage-based architecture of information channels enable the modification of neural networks across existing, novel, and deprecated modalities in a species-specific manner, thus forming the substrate for the evolution and diversification of insect navigational circuits.
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Affiliation(s)
- Pratyush Kandimalla
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, CA, USA.
| | - Jaison Jiro Omoto
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, CA, USA
| | - Elizabeth J Hong
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Volker Hartenstein
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, CA, USA
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7
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Mitchell R, Shaverdian S, Dacke M, Webb B. A model of cue integration as vector summation in the insect brain. Proc Biol Sci 2023; 290:20230767. [PMID: 37357865 PMCID: PMC10291719 DOI: 10.1098/rspb.2023.0767] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 05/30/2023] [Indexed: 06/27/2023] Open
Abstract
Ball-rolling dung beetles are known to integrate multiple cues in order to facilitate their straight-line orientation behaviour. Recent work has suggested that orientation cues are integrated according to a vector sum, that is, compass cues are represented by vectors and summed to give a combined orientation estimate. Further, cue weight (vector magnitude) appears to be set according to cue reliability. This is consistent with the popular Bayesian view of cue integration: cues are integrated to reduce or minimize an agent's uncertainty about the external world. Integration of orientation cues is believed to occur at the input to the insect central complex. Here, we demonstrate that a model of the head direction circuit of the central complex, including plasticity in input synapses, can act as a substrate for cue integration as vector summation. Further, we show that cue influence is not necessarily driven by cue reliability. Finally, we present a dung beetle behavioural experiment which, in combination with simulation, strongly suggests that these beetles do not weight cues according to reliability. We suggest an alternative strategy whereby cues are weighted according to relative contrast, which can also explain previous results.
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Affiliation(s)
- Robert Mitchell
- Institute for Perception, Action, and Behaviour, The University of Edinburgh School of Informatics, Edinburgh, Edinburgh EH8 9AB, UK
| | - Shahrzad Shaverdian
- Lund Vision Group, Department of Biology, Lund University, Lund SE-223 62, Sweden
| | - Marie Dacke
- Lund Vision Group, Department of Biology, Lund University, Lund SE-223 62, Sweden
| | - Barbara Webb
- Institute for Perception, Action, and Behaviour, The University of Edinburgh School of Informatics, Edinburgh, Edinburgh EH8 9AB, UK
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8
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Beetz MJ, El Jundi B. The influence of stimulus history on directional coding in the monarch butterfly brain. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2023:10.1007/s00359-023-01633-x. [PMID: 37095358 DOI: 10.1007/s00359-023-01633-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 04/05/2023] [Accepted: 04/12/2023] [Indexed: 04/26/2023]
Abstract
The central complex is a brain region in the insect brain that houses a neural network specialized to encode directional information. Directional coding has traditionally been investigated with compass cues that revolve in full rotations and at constant angular velocities around the insect's head. However, these stimulus conditions do not fully simulate an insect's sensory perception of compass cues during navigation. In nature, an insect flight is characterized by abrupt changes in moving direction as well as constant changes in velocity. The influence of such varying cue dynamics on compass coding remains unclear. We performed long-term tetrode recordings from the brain of monarch butterflies to study how central complex neurons respond to different stimulus velocities and directions. As these butterflies derive directional information from the sun during migration, we measured the neural response to a virtual sun. The virtual sun was either presented as a spot that appeared at random angular positions or was rotated around the butterfly at different angular velocities and directions. By specifically manipulating the stimulus velocity and trajectory, we dissociated the influence of angular velocity and direction on compass coding. While the angular velocity substantially affected the tuning directedness, the stimulus trajectory influenced the shape of the angular tuning curve. Taken together, our results suggest that the central complex flexibly adjusts its directional coding to the current stimulus dynamics ensuring a precise compass even under highly demanding conditions such as during rapid flight maneuvers.
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Affiliation(s)
- M Jerome Beetz
- Zoology II, Biocenter, University of Würzburg, Würzburg, Germany.
| | - Basil El Jundi
- Zoology II, Biocenter, University of Würzburg, Würzburg, Germany
- Animal Physiology, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
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9
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Althaus V, Jahn S, Massah A, Stengl M, Homberg U. 3D-atlas of the brain of the cockroach Rhyparobia maderae. J Comp Neurol 2022; 530:3126-3156. [PMID: 36036660 DOI: 10.1002/cne.25396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/21/2022] [Accepted: 07/24/2022] [Indexed: 11/07/2022]
Abstract
The Madeira cockroach Rhyparobia maderae is a nocturnal insect and a prominent model organism for the study of circadian rhythms. Its master circadian clock, controlling circadian locomotor activity and sleep-wake cycles, is located in the accessory medulla of the optic lobe. For a better understanding of brain regions controlled by the circadian clock and brain organization of this insect in general, we created a three-dimensional (3D) reconstruction of all neuropils of the cerebral ganglia based on anti-synapsin and anti-γ-aminobutyric acid immunolabeling of whole mount brains. Forty-nine major neuropils were identified and three-dimensionally reconstructed. Single-cell dye fills complement the data and provide evidence for distinct subdivisions of certain brain areas. Most neuropils defined in the fruit fly Drosophila melanogaster could be distinguished in the cockroach as well. However, some neuropils identified in the fruit fly do not exist as distinct entities in the cockroach while others are lacking in the fruit fly. In addition to neuropils, major fiber systems, tracts, and commissures were reconstructed and served as important landmarks separating brain areas. Being a nocturnal insect, R. maderae is an important new species to the growing collection of 3D insect brain atlases and only the second hemimetabolous insect, for which a detailed 3D brain atlas is available. This atlas will be highly valuable for an evolutionary comparison of insect brain organization and will greatly facilitate addressing brain areas that are supervised by the circadian clock.
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Affiliation(s)
- Vanessa Althaus
- Department of Biology, Animal Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Stefanie Jahn
- Department of Biology, Animal Physiology, Philipps-University of Marburg, Marburg, Germany
| | - Azar Massah
- Faculty of Mathematics and Natural Sciences, Institute of Biology, Animal Physiology, University of Kassel, Kassel, Germany
| | - Monika Stengl
- Faculty of Mathematics and Natural Sciences, Institute of Biology, Animal Physiology, University of Kassel, Kassel, Germany
| | - Uwe Homberg
- Department of Biology, Animal Physiology, Philipps-University of Marburg, Marburg, Germany
- Center for Mind Brain and Behavior (CMBB), University of Marburg and Justus Liebig University of Giessen, Marburg, Germany
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10
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Nguyen TAT, Beetz MJ, Merlin C, Pfeiffer K, el Jundi B. Weighting of Celestial and Terrestrial Cues in the Monarch Butterfly Central Complex. Front Neural Circuits 2022; 16:862279. [PMID: 35847485 PMCID: PMC9285895 DOI: 10.3389/fncir.2022.862279] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 06/10/2022] [Indexed: 12/02/2022] Open
Abstract
Monarch butterflies rely on external cues for orientation during their annual long-distance migration from Northern US and Canada to Central Mexico. These external cues can be celestial cues, such as the sun or polarized light, which are processed in a brain region termed the central complex (CX). Previous research typically focused on how individual simulated celestial cues are encoded in the butterfly's CX. However, in nature, the butterflies perceive several celestial cues at the same time and need to integrate them to effectively use the compound of all cues for orientation. In addition, a recent behavioral study revealed that monarch butterflies can rely on terrestrial cues, such as the panoramic skyline, for orientation and use them in combination with the sun to maintain a directed flight course. How the CX encodes a combination of celestial and terrestrial cues and how they are weighted in the butterfly's CX is still unknown. Here, we examined how input neurons of the CX, termed TL neurons, combine celestial and terrestrial information. While recording intracellularly from the neurons, we presented a sun stimulus and polarized light to the butterflies as well as a simulated sun and a panoramic scene simultaneously. Our results show that celestial cues are integrated linearly in these cells, while the combination of the sun and a panoramic skyline did not always follow a linear integration of action potential rates. Interestingly, while the sun and polarized light were invariantly weighted between individual neurons, the sun stimulus and panoramic skyline were dynamically weighted when both stimuli were simultaneously presented. Taken together, this dynamic weighting between celestial and terrestrial cues may allow the butterflies to flexibly set their cue preference during navigation.
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Affiliation(s)
| | - M. Jerome Beetz
- Biocenter, Zoology II, University of Wuerzburg, Würzburg, Germany
| | - Christine Merlin
- Department of Biology and Center for Biological Clocks Research, Texas A&M University, College Station, TX, United States
| | - Keram Pfeiffer
- Biocenter, Zoology II, University of Wuerzburg, Würzburg, Germany
| | - Basil el Jundi
- Biocenter, Zoology II, University of Wuerzburg, Würzburg, Germany
- Department of Biology, Animal Physiology, Norwegian University of Science and Technology, Trondheim, Norway
- *Correspondence: Basil el Jundi
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11
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Hensgen R, Dippel S, Hümmert S, Jahn S, Seyfarth J, Homberg U. Myoinhibitory peptides in the central complex of the locust Schistocerca gregaria and colocalization with locustatachykinin-related peptides. J Comp Neurol 2022; 530:2782-2801. [PMID: 35700405 DOI: 10.1002/cne.25374] [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: 01/18/2022] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 11/10/2022]
Abstract
The central complex in the brain of insects provides a neural network for sensorimotor processing that is essential for spatial navigation and locomotion and plays a role in sleep control. Studies on the neurochemical architecture of the central complex have been performed especially in the fruit fly Drosophila melangoaster and the desert locust, Schistocerca gregaria. In several insect species, myoinhibitory peptides (MIPs) are involved in circadian control and sleep-wake regulation. To identify neurons that might underlie these functions, we investigated the distribution of MIPs in the central complex of the locust. In silico transcript analysis suggests the presence of eight different MIPs in the desert locust. Through immunolabeling, we identified five systems of central-complex neurons that express MIP-like peptides. Two systems constitute columnar neurons of the protocerebral bridge and the lower division of the central body, while the other three systems are columnar neurons (two systems) and tangential neurons (one system) of the upper division of the central body. The innervation pattern and cell count of two systems of columnar neurons revealed the existence of 18 instead of 16 columns of the protocerebral bridge. Immunostaining of preparations containing intracellularly stained single cells allowed us to further specify subtypes of labeled columnar neurons. Double-label experiments showed that three systems of MIP-immunostained columnar neurons are also locustatachykinin-immunoreactive. No colocalization was found with serotonin immunostaining. The data provide novel insights into the architecture of the locust central complex and suggest that MIPs play a prominent role within the central-complex network.
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Affiliation(s)
- Ronja Hensgen
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
| | - Stefan Dippel
- Department of Biology, Zoology, and Developmental Biology, Justus Liebig University of Giessen, Gießen, Germany
| | - Sophie Hümmert
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
| | - Stefanie Jahn
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
| | - Jutta Seyfarth
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
| | - Uwe Homberg
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany.,Center for Mind, Brain, and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Marburg, Germany
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12
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Kaiser A, Hensgen R, Tschirner K, Beetz E, Wüstenberg H, Pfaff M, Mota T, Pfeiffer K. A three-dimensional atlas of the honeybee central complex, associated neuropils and peptidergic layers of the central body. J Comp Neurol 2022; 530:2416-2438. [PMID: 35593178 DOI: 10.1002/cne.25339] [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: 03/13/2022] [Revised: 04/15/2022] [Accepted: 04/26/2022] [Indexed: 11/11/2022]
Abstract
The central complex (CX) in the brain of insects is a highly conserved group of midline-spanning neuropils consisting of the upper and lower division of the central body, the protocerebral bridge, and the paired noduli. These neuropils are the substrate for a number of behaviors, most prominently goal-oriented locomotion. Honeybees have been a model organism for sky-compass orientation for more than 70 years, but there is still very limited knowledge about the structure and function of their CX. To advance and facilitate research on this brain area, we created a high-resolution three-dimensional atlas of the honeybee's CX and associated neuropils, including the posterior optic tubercles, the bulbs, and the anterior optic tubercles. To this end, we developed a modified version of the iterative shape averaging technique, which allowed us to achieve high volumetric accuracy of the neuropil models. For a finer definition of spatial locations within the central body, we defined layers based on immunostaining against the neuropeptides locustatachykinin, FMRFamide, gastrin/cholecystokinin, and allatostatin and included them into the atlas by elastic registration. Our honeybee CX atlas provides a platform for future neuroanatomical work.
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Affiliation(s)
- Andreas Kaiser
- Department of Biology/Animal Physiology, Philipps-University Marburg, Marburg, Germany
| | - Ronja Hensgen
- Department of Biology/Animal Physiology, Philipps-University Marburg, Marburg, Germany
| | - Katja Tschirner
- Behavioural Physiology and Sociobiology (Zoology II), Biocenter, University of Würzburg, Würzburg, Germany
| | - Evelyn Beetz
- Behavioural Physiology and Sociobiology (Zoology II), Biocenter, University of Würzburg, Würzburg, Germany
| | - Hauke Wüstenberg
- Department of Biology/Animal Physiology, Philipps-University Marburg, Marburg, Germany
| | - Marcel Pfaff
- Behavioural Physiology and Sociobiology (Zoology II), Biocenter, University of Würzburg, Würzburg, Germany
| | - Theo Mota
- Department of Physiology and Biophysics, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Keram Pfeiffer
- Department of Biology/Animal Physiology, Philipps-University Marburg, Marburg, Germany.,Behavioural Physiology and Sociobiology (Zoology II), Biocenter, University of Würzburg, Würzburg, Germany
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13
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Martin C, Jahn H, Klein M, Hammel JU, Stevenson PA, Homberg U, Mayer G. The velvet worm brain unveils homologies and evolutionary novelties across panarthropods. BMC Biol 2022; 20:26. [PMID: 35073910 PMCID: PMC9136957 DOI: 10.1186/s12915-021-01196-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 11/16/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The evolution of the brain and its major neuropils in Panarthropoda (comprising Arthropoda, Tardigrada and Onychophora) remains enigmatic. As one of the closest relatives of arthropods, onychophorans are regarded as indispensable for a broad understanding of the evolution of panarthropod organ systems, including the brain, whose anatomical and functional organisation is often used to gain insights into evolutionary relations. However, while numerous recent studies have clarified the organisation of many arthropod nervous systems, a detailed investigation of the onychophoran brain with current state-of-the-art approaches is lacking, and further inconsistencies in nomenclature and interpretation hamper its understanding. To clarify the origins and homology of cerebral structures across panarthropods, we analysed the brain architecture in the onychophoran Euperipatoides rowelli by combining X-ray micro-computed tomography, histology, immunohistochemistry, confocal microscopy, and three-dimensional reconstruction. RESULTS Here, we use this detailed information to generate a consistent glossary for neuroanatomical studies of Onychophora. In addition, we report novel cerebral structures, provide novel details on previously known brain areas, and characterise further structures and neuropils in order to improve the reproducibility of neuroanatomical observations. Our findings support homology of mushroom bodies and central bodies in onychophorans and arthropods. Their antennal nerve cords and olfactory lobes most likely evolved independently. In contrast to previous reports, we found no evidence for second-order visual neuropils, or a frontal ganglion in the velvet worm brain. CONCLUSION We imaged the velvet worm nervous system at an unprecedented level of detail and compiled a comprehensive glossary of known and previously uncharacterised neuroanatomical structures to provide an in-depth characterisation of the onychophoran brain architecture. We expect that our data will improve the reproducibility and comparability of future neuroanatomical studies.
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Affiliation(s)
- Christine Martin
- Department of Zoology, Institute of Biology, University of Kassel, 34132, Kassel, Germany.
| | - Henry Jahn
- Department of Zoology, Institute of Biology, University of Kassel, 34132, Kassel, Germany
| | - Mercedes Klein
- Department of Zoology, Institute of Biology, University of Kassel, 34132, Kassel, Germany
| | - Jörg U Hammel
- Institute of Materials Physics, Helmholtz-Zentrum hereon, 21502, Geesthacht, Germany
| | - Paul A Stevenson
- Physiology of Animals and Behaviour, Institute of Biology, University of Leipzig, 04103, Leipzig, Germany
| | - Uwe Homberg
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, 35043, Marburg, Germany
- Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, 35032, Marburg, Germany
| | - Georg Mayer
- Department of Zoology, Institute of Biology, University of Kassel, 34132, Kassel, Germany.
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14
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Internal state effects on behavioral shifts in freely behaving praying mantises (Tenodera sinensis). PLoS Comput Biol 2021; 17:e1009618. [PMID: 34928939 PMCID: PMC8751982 DOI: 10.1371/journal.pcbi.1009618] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 01/11/2022] [Accepted: 11/05/2021] [Indexed: 11/19/2022] Open
Abstract
How we interact with our environment largely depends on both the external cues presented by our surroundings and the internal state from within. Internal states are the ever-changing physiological conditions that communicate the immediate survival needs and motivate the animal to behaviorally fulfill them. Satiety level constitutes such a state, and therefore has a dynamic influence on the output behaviors of an animal. In predatory insects like the praying mantis, hunting tactics, grooming, and mating have been shown to change hierarchical organization of behaviors depending on satiety. Here, we analyze behavior sequences of freely hunting praying mantises (Tenodera sinensis) to explore potential differences in sequential patterning of behavior as a correlate of satiety. First, our data supports previous work that showed starved praying mantises were not just more often attentive to prey, but also more often attentive to further prey. This was indicated by the increased time fraction spent in attentive bouts such as prey monitoring, head turns (to track prey), translations (closing the distance to the prey), and more strike attempts. With increasing satiety, praying mantises showed reduced time in these behaviors and exhibited them primarily towards close-proximity prey. Furthermore, our data demonstrates that during states of starvation, the praying mantis exhibits a stereotyped pattern of behavior that is highly motivated by prey capture. As satiety increased, the sequenced behaviors became more variable, indicating a shift away from the necessity of prey capture to more fluid presentations of behavior assembly.
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15
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Hulse BK, Haberkern H, Franconville R, Turner-Evans D, 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:e66039. [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] [MESH Headings] [Grants] [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.
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Affiliation(s)
- Brad K Hulse
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Hannah Haberkern
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Romain Franconville
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Daniel Turner-Evans
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Shin-ya Takemura
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Tanya Wolff
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Marcella Noorman
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Marisa Dreher
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Chuntao Dan
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Ruchi Parekh
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Ann M Hermundstad
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Gerald M Rubin
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
| | - Vivek Jayaraman
- Janelia Research Campus, Howard Hughes Medical InstituteAshburnUnited States
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16
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Sayre ME, Templin R, Chavez J, Kempenaers J, Heinze S. A projectome of the bumblebee central complex. eLife 2021; 10:e68911. [PMID: 34523418 PMCID: PMC8504972 DOI: 10.7554/elife.68911] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 09/14/2021] [Indexed: 12/29/2022] Open
Abstract
Insects have evolved diverse and remarkable strategies for navigating in various ecologies all over the world. Regardless of species, insects share the presence of a group of morphologically conserved neuropils known collectively as the central complex (CX). The CX is a navigational center, involved in sensory integration and coordinated motor activity. Despite the fact that our understanding of navigational behavior comes predominantly from ants and bees, most of what we know about the underlying neural circuitry of such behavior comes from work in fruit flies. Here, we aim to close this gap, by providing the first comprehensive map of all major columnar neurons and their projection patterns in the CX of a bee. We find numerous components of the circuit that appear to be highly conserved between the fly and the bee, but also highlight several key differences which are likely to have important functional ramifications.
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Affiliation(s)
- Marcel Ethan Sayre
- Lund University, Lund Vision Group, Department of BiologyLundSweden
- Macquarie University, Department of Biological SciencesSydneyAustralia
| | - Rachel Templin
- Queensland Brain Institute, University of QueenslandBrisbaneSweden
| | - Johanna Chavez
- Lund University, Lund Vision Group, Department of BiologyLundSweden
| | | | - Stanley Heinze
- Lund University, Lund Vision Group, Department of BiologyLundSweden
- Lund University, NanoLundLundSweden
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17
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Heinze S, El Jundi B, Berg BG, Homberg U, Menzel R, Pfeiffer K, Hensgen R, Zittrell F, Dacke M, Warrant E, Pfuhl G, Rybak J, Tedore K. A unified platform to manage, share, and archive morphological and functional data in insect neuroscience. eLife 2021; 10:65376. [PMID: 34427185 PMCID: PMC8457822 DOI: 10.7554/elife.65376] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 08/21/2021] [Indexed: 01/08/2023] Open
Abstract
Insect neuroscience generates vast amounts of highly diverse data, of which only a small fraction are findable, accessible and reusable. To promote an open data culture, we have therefore developed the InsectBrainDatabase (IBdb), a free online platform for insect neuroanatomical and functional data. The IBdb facilitates biological insight by enabling effective cross-species comparisons, by linking neural structure with function, and by serving as general information hub for insect neuroscience. The IBdb allows users to not only effectively locate and visualize data, but to make them widely available for easy, automated reuse via an application programming interface. A unique private mode of the database expands the IBdb functionality beyond public data deposition, additionally providing the means for managing, visualizing, and sharing of unpublished data. This dual function creates an incentive for data contribution early in data management workflows and eliminates the additional effort normally associated with publicly depositing research data. Insect neuroscience, like any field in the natural sciences, generates vast amounts of data. Currently, only a fraction are publicly available, and even less are reusable. This is because insect neuroscience data come in many formats and from many species. Some experiments focus on what insect brains look like (morphology), while others focus on how insect brains work (function). Some data come in the form of high-speed video, while other data contain voltage traces from individual neurons. Sharing is not as simple as uploading the raw files to the internet. To get a clear picture of how insect brains work, researchers need a way to cross-reference and connect different experiments. But, as it stands, there is no dedicated place for insect neuroscientists to share and explore such a diverse body of work. The community needs an open data repository that can link different types of data across many species, and can evolve as more data become available. Above all, this repository needs to be easy for researchers to use. To meet these specifications, Heinze et al. developed the Insect Brain Database. The database organizes data into three categories: species, brain structures, and neuron types. Within these categories, each entry has its own profile page. These pages bring different experiments together under one heading, allowing researchers to combine and compare data of different types. As researchers add more experiments, the profile pages will grow and evolve. To make the data easy to navigate, Heinze et al. developed a visual search tool. A combination of 2D and 3D images allow users to explore the data by anatomical location, without the need for expert knowledge. Researchers also have the option to upload their work in private mode, allowing them to securely share unpublished data. The Insect Brain Database brings data together in a way that is accessible not only to researchers, but also to students, and non-scientists. It will help researchers to find related work, to reuse existing data, and to build an open data culture. This has the potential to drive new discoveries combining research across the whole of the insect neuroscience field.
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Affiliation(s)
- Stanley Heinze
- Department of Biology, Lund University, Lund, Sweden.,NanoLund, Lund University, Lund, Sweden
| | - Basil El Jundi
- Biocenter, Behavioral Physiology and Sociobiology, University of Würzburg, Würzburg, Germany
| | - Bente G Berg
- Department of Psychology, Chemosensory lab, Norwegian University of Science and Technology, Trondheim, Norway
| | - Uwe Homberg
- Fachbereich Biologie, Tierphysiologie, and Center for Mind Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Marburg, Germany
| | - Randolf Menzel
- Institut für Biologie - Neurobiologie, Free University, Berlin, Germany
| | - Keram Pfeiffer
- Biocenter, Behavioral Physiology and Sociobiology, University of Würzburg, Würzburg, Germany
| | - Ronja Hensgen
- Fachbereich Biologie, Tierphysiologie, and Center for Mind Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Marburg, Germany
| | - Frederick Zittrell
- Fachbereich Biologie, Tierphysiologie, and Center for Mind Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Marburg, Germany
| | - Marie Dacke
- Department of Biology, Lund University, Lund, Sweden
| | - Eric Warrant
- Research School of Biology, Australian National University, Canberra, Australia
| | - Gerit Pfuhl
- Department of Psychology, Chemosensory lab, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Psychology, UiT The Arctic University of Norway, Tromso, Norway
| | - Jürgen Rybak
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Kevin Tedore
- Department of Biology, Lund University, Lund, Sweden
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18
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Hensgen R, Göthe J, Jahn S, Hümmert S, Schneider KL, Takahashi N, Pegel U, Gotthardt S, Homberg U. Organization and neural connections of the lateral complex in the brain of the desert locust. J Comp Neurol 2021; 529:3533-3560. [PMID: 34216020 DOI: 10.1002/cne.25209] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 06/24/2021] [Accepted: 06/28/2021] [Indexed: 11/08/2022]
Abstract
The lateral complexes (LXs) are bilaterally paired neuropils in the insect brain that mediate communication between the central complex (CX), a brain center controlling spatial orientation, various sensory processing areas, and thoracic motor centers that execute locomotion. The LX of the desert locust consists of the lateral accessory lobe (LAL), and the medial and lateral bulb. We have analyzed the anatomical organization and the neuronal connections of the LX in the locust, to provide a basis for future functional studies. Reanalyzing the morphology of neurons connecting the CX and the LX revealed likely feedback loops in the sky compass network of the CX via connections in the gall of the LAL and a newly identified neuropil termed ovoid body. In addition, we characterized 16 different types of neuron that connect the LAL with other areas in the brain. Eight types of neuron provide information flow between both LALs, five types are LAL input neurons, and three types are LAL output neurons. Among these are neurons providing input from sensory brain areas such as the lobula and antennal neuropils. Brain regions most often targeted by LAL neurons are the posterior slope, the wedge, and the crepine. Two descending neurons with dendrites in the LAL were identified. Our data support and complement existing knowledge about how the LAL is embedded in the neuronal network involved in processing of sensory information and generation of appropriate behavioral output for goal-directed locomotion.
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Affiliation(s)
- Ronja Hensgen
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
| | - Jonas Göthe
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
| | - Stefanie Jahn
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
| | - Sophie Hümmert
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
| | - Kim Lucia Schneider
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
| | - Naomi Takahashi
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
| | - Uta Pegel
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
| | - Sascha Gotthardt
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany
| | - Uwe Homberg
- Department of Biology, Animal Physiology, Philipps-Universität Marburg, Marburg, Germany.,Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Marburg, Germany
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19
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Rother L, Kraft N, Smith DB, El Jundi B, Gill RJ, Pfeiffer K. A micro-CT-based standard brain atlas of the bumblebee. Cell Tissue Res 2021; 386:29-45. [PMID: 34181089 PMCID: PMC8526489 DOI: 10.1007/s00441-021-03482-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 06/03/2021] [Indexed: 02/07/2023]
Abstract
In recent years, bumblebees have become a prominent insect model organism for a variety of biological disciplines, particularly to investigate learning behaviors as well as visual performance. Understanding these behaviors and their underlying neurobiological principles requires a clear understanding of brain anatomy. Furthermore, to be able to compare neuronal branching patterns across individuals, a common framework is required, which has led to the development of 3D standard brain atlases in most of the neurobiological insect model species. Yet, no bumblebee 3D standard brain atlas has been generated. Here we present a brain atlas for the buff-tailed bumblebee Bombus terrestris using micro-computed tomography (micro-CT) scans as a source for the raw data sets, rather than traditional confocal microscopy, to produce the first ever micro-CT-based insect brain atlas. We illustrate the advantages of the micro-CT technique, namely, identical native resolution in the three cardinal planes and 3D structure being better preserved. Our Bombus terrestris brain atlas consists of 30 neuropils reconstructed from ten individual worker bees, with micro-CT allowing us to segment neuropils completely intact, including the lamina, which is a tissue structure often damaged when dissecting for immunolabeling. Our brain atlas can serve as a platform to facilitate future neuroscience studies in bumblebees and illustrates the advantages of micro-CT for specific applications in insect neuroanatomy.
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Affiliation(s)
- Lisa Rother
- Department of Behavioral Physiology and Sociobiology, Biocenter, University of Würzburg, 97074, Würzburg, Germany
| | - Nadine Kraft
- Department of Behavioral Physiology and Sociobiology, Biocenter, University of Würzburg, 97074, Würzburg, Germany
| | - Dylan B Smith
- Department of Life Sciences, Imperial College London, Silwood Park, Buckhurst Road, Ascot, Berkshire, SL5 7PY, UK
| | - Basil El Jundi
- Department of Behavioral Physiology and Sociobiology, Biocenter, University of Würzburg, 97074, Würzburg, Germany
| | - Richard J Gill
- Department of Life Sciences, Imperial College London, Silwood Park, Buckhurst Road, Ascot, Berkshire, SL5 7PY, UK
| | - Keram Pfeiffer
- Department of Behavioral Physiology and Sociobiology, Biocenter, University of Würzburg, 97074, Würzburg, Germany.
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20
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Dacke M, Baird E, El Jundi B, Warrant EJ, Byrne M. How Dung Beetles Steer Straight. ANNUAL REVIEW OF ENTOMOLOGY 2021; 66:243-256. [PMID: 32822556 DOI: 10.1146/annurev-ento-042020-102149] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Distant and predictable features in the environment make ideal compass cues to allow movement along a straight path. Ball-rolling dung beetles use a wide range of different signals in the day or night sky to steer themselves along a fixed bearing. These include the sun, the Milky Way, and the polarization pattern generated by the moon. Almost two decades of research into these remarkable creatures have shown that the dung beetle's compass is flexible and readily adapts to the cues available in its current surroundings. In the morning and afternoon, dung beetles use the sun to orient, but at midday, they prefer to use the wind, and at night or in a forest, they rely primarily on polarized skylight to maintain straight paths. We are just starting to understand the neuronal substrate underlying the dung beetle's compass and the mystery of why these beetles start each journey with a dance.
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Affiliation(s)
- Marie Dacke
- Department of Biology, Lund University, 223 62 Lund, Sweden; ,
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa;
| | - Emily Baird
- Department of Zoology, Stockholm University, 106 91 Stockholm, Sweden;
| | - Basil El Jundi
- Biocenter, University of Wuerzburg, 97074 Wuerzburg, Germany;
| | - Eric J Warrant
- Department of Biology, Lund University, 223 62 Lund, Sweden; ,
| | - Marcus Byrne
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa;
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21
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Homberg U, Hensgen R, Rieber E, Seyfarth J, Kern M, Dippel S, Dircksen H, Spänig L, Kina YP. Orcokinin in the central complex of the locust Schistocerca gregaria: Identification of immunostained neurons and colocalization with other neuroactive substances. J Comp Neurol 2020; 529:1876-1894. [PMID: 33128250 DOI: 10.1002/cne.25062] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 10/22/2020] [Accepted: 10/22/2020] [Indexed: 12/20/2022]
Abstract
The central complex is a group of highly interconnected neuropils in the insect brain. It is involved in the control of spatial orientation, based on external compass cues and various internal needs. The functional and neurochemical organization of the central complex has been studied in detail in the desert locust Schistocerca gregaria. In addition to classical neurotransmitters, immunocytochemistry has provided evidence for a major contribution of neuropeptides to neural signaling within the central complex. To complement these data, we have identified all orcokinin-immunoreactive neurons in the locust central complex and associated brain areas. About 50 bilateral pairs of neurons innervating all substructures of the central complex exhibit orcokinin immunoreactivity. Among these were about 20 columnar neurons, 33 bilateral pairs of tangential neurons of the central body, and seven pairs of tangential neurons of the protocerebral bridge. In silico transcript analysis suggests the presence of eight different orcokinin-A type peptides in the desert locust. Double label experiments showed that all orcokinin-immunostained tangential neurons of the lateral accessory lobe cluster were also immunoreactive for GABA and the GABA-synthesizing enzyme glutamic acid decarboxylase. Two types of tangential neurons of the upper division of the central body were, furthermore, also labeled with an antiserum against Dip-allatostatin I. No colocalization was found with serotonin immunostaining. The data provide additional insights into the neurochemical organization of the locust central complex and suggest that orcokinin-peptides of the orcokinin-A gene act as neuroactive substances at all stages of signal processing in this brain area.
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Affiliation(s)
- Uwe Homberg
- Department of Biology, Animal Physiology & Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Marburg, Germany
| | - Ronja Hensgen
- Department of Biology, Animal Physiology & Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Marburg, Germany
| | - Evelyn Rieber
- Department of Biology, Animal Physiology & Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Marburg, Germany.,Behavioral Physiology and Sociobiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Jutta Seyfarth
- Department of Biology, Animal Physiology & Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Marburg, Germany
| | - Martina Kern
- Department of Biology, Animal Physiology & Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Marburg, Germany
| | - Stefan Dippel
- Department of Biology, Animal Physiology & Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Marburg, Germany
| | | | - Lisa Spänig
- Department of Biology, Animal Physiology & Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Marburg, Germany
| | - Yelda Pakize Kina
- Department of Biology, Animal Physiology & Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Marburg, Germany
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22
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Sequence heterochrony led to a gain of functionality in an immature stage of the central complex: A fly-beetle insight. PLoS Biol 2020; 18:e3000881. [PMID: 33104689 PMCID: PMC7644108 DOI: 10.1371/journal.pbio.3000881] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 11/05/2020] [Accepted: 09/18/2020] [Indexed: 12/25/2022] Open
Abstract
Animal behavior is guided by the brain. Therefore, adaptations of brain structure and function are essential for animal survival, and each species differs in such adaptations. The brain of one individual may even differ between life stages, for instance, as adaptation to the divergent needs of larval and adult life of holometabolous insects. All such differences emerge during development, but the cellular mechanisms behind the diversification of brains between taxa and life stages remain enigmatic. In this study, we investigated holometabolous insects in which larvae differ dramatically from the adult in both behavior and morphology. As a consequence, the central complex, mainly responsible for spatial orientation, is conserved between species at the adult stage but differs between larvae and adults of one species as well as between larvae of different taxa. We used genome editing and established transgenic lines to visualize cells expressing the conserved transcription factor retinal homeobox, thereby marking homologous genetic neural lineages in both the fly Drosophila melanogaster and the beetle Tribolium castaneum. This approach allowed us for the first time to compare the development of homologous neural cells between taxa from embryo to the adult. We found complex heterochronic changes including shifts of developmental events between embryonic and pupal stages. Further, we provide, to our knowledge, the first example of sequence heterochrony in brain development, where certain developmental steps changed their position within the ontogenetic progression. We show that through this sequence heterochrony, an immature developmental stage of the central complex gains functionality in Tribolium larvae. The central complex, part of the brain responsible for spatial orientation, differs between insect species and life stages. This study marks and compares the development of homologous neurons between a beetle and a fly, revealing that by heterochronic development an immature form of the central complex becomes functional in beetle larvae.
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23
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Timaeus L, Geid L, Sancer G, Wernet MF, Hummel T. Parallel Visual Pathways with Topographic versus Nontopographic Organization Connect the Drosophila Eyes to the Central Brain. iScience 2020; 23:101590. [PMID: 33205011 PMCID: PMC7648135 DOI: 10.1016/j.isci.2020.101590] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/21/2020] [Accepted: 09/16/2020] [Indexed: 11/12/2022] Open
Abstract
One hallmark of the visual system is a strict retinotopic organization from the periphery toward the central brain, where functional imaging in Drosophila revealed a spatially accurate representation of visual cues in the central complex. This raised the question how, on a circuit level, the topographic features are implemented, as the majority of visual neurons enter the central brain converge in optic glomeruli. We discovered a spatial segregation of topographic versus nontopographic projections of distinct classes of medullo-tubercular (MeTu) neurons into a specific visual glomerulus, the anterior optic tubercle (AOTU). These parallel channels synapse onto different tubercular-bulbar (TuBu) neurons, which in turn relay visual information onto specific central complex ring neurons in the bulb neuropil. Hence, our results provide the circuit basis for spatially accurate representation of visual information and highlight the AOTU's role as a prominent relay station for spatial information from the retina to the central brain. A Drosophila visual circuit conveys input from the periphery to the central brain Several synaptic pathways form parallel channels using the anterior optic tubercle Some pathways maintain topographic relationships across several synaptic steps Different target neurons in the central brain are identified
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Affiliation(s)
- Lorin Timaeus
- Department of Neurobiology, University of Vienna, Vienna, Austria
| | - Laura Geid
- Department of Neurobiology, University of Vienna, Vienna, Austria.,Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Gizem Sancer
- Department of Biology, Freie Universität Berlin, Berlin, Germany
| | - Mathias F Wernet
- Department of Biology, Freie Universität Berlin, Berlin, Germany
| | - Thomas Hummel
- Department of Neurobiology, University of Vienna, Vienna, Austria
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24
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Held M, Le K, Pegel U, Dersch F, Beetz MJ, Pfeiffer K, Homberg U. Anatomical and ultrastructural analysis of the posterior optic tubercle in the locust Schistocerca gregaria. ARTHROPOD STRUCTURE & DEVELOPMENT 2020; 58:100971. [PMID: 32755758 DOI: 10.1016/j.asd.2020.100971] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 06/22/2020] [Accepted: 07/03/2020] [Indexed: 06/11/2023]
Abstract
Locusts, like other insects, partly rely on a sun compass mechanism for spatial orientation during seasonal migrations. To serve as a useful guiding cue throughout the day, however, the sun's apparent movement has to be accounted for. In locusts, a neural pathway from the accessory medulla, the circadian pacemaker, via the posterior optic tubercle, to the protocerebral bridge, part of the internal sky compass, has been proposed to mediate the required time compensation. Toward a better understanding of neural connectivities within the posterior optic tubercle, we investigated this neuropil using light and electron microscopy. Based on vesicle content, four types of synaptic profile were distinguished within the posterior optic tubercle. Immunogold labeling showed that pigment-dispersing hormone immunoreactive neurons from the accessory medulla, containing large dense-core vesicles, have presynaptic terminals in the posterior optic tubercle. Ultrastructural examination of two Neurobiotin-injected tangential neurons of the protocerebral bridge revealed that these neurons are postsynaptic in the posterior optic tubercle. Our data, therefore, support a role of the posterior optic tubercles in mediating circadian input to the insect sky compass.
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Affiliation(s)
- Martina Held
- Animal Physiology, Department of Biology & Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany.
| | - Kim Le
- Animal Physiology, Department of Biology & Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Uta Pegel
- Animal Physiology, Department of Biology & Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Florian Dersch
- Animal Physiology, Department of Biology & Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - M Jerome Beetz
- Animal Physiology, Department of Biology & Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Keram Pfeiffer
- Animal Physiology, Department of Biology & Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Uwe Homberg
- Animal Physiology, Department of Biology & Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
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25
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Pisokas I, Heinze S, Webb B. The head direction circuit of two insect species. eLife 2020; 9:e53985. [PMID: 32628112 PMCID: PMC7419142 DOI: 10.7554/elife.53985] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 07/06/2020] [Indexed: 01/30/2023] Open
Abstract
Recent studies of the Central Complex in the brain of the fruit fly have identified neurons with activity that tracks the animal's heading direction. These neurons are part of a neuronal circuit with dynamics resembling those of a ring attractor. The homologous circuit in other insects has similar topographic structure but with significant structural and connectivity differences. We model the connectivity patterns of two insect species to investigate the effect of these differences on the dynamics of the circuit. We illustrate that the circuit found in locusts can also operate as a ring attractor but differences in the inhibition pattern enable the fruit fly circuit to respond faster to heading changes while additional recurrent connections render the locust circuit more tolerant to noise. Our findings demonstrate that subtle differences in neuronal projection patterns can have a significant effect on circuit performance and illustrate the need for a comparative approach in neuroscience.
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Affiliation(s)
- Ioannis Pisokas
- School of Informatics, University of EdinburghEdinburghUnited Kingdom
| | - Stanley Heinze
- Lund Vision Group and NanoLund, Lund UniversityLundSweden
| | - Barbara Webb
- School of Informatics, University of EdinburghEdinburghUnited Kingdom
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26
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Habenstein J, Amini E, Grübel K, el Jundi B, Rössler W. The brain of
Cataglyphis
ants: Neuronal organization and visual projections. J Comp Neurol 2020; 528:3479-3506. [DOI: 10.1002/cne.24934] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 04/15/2020] [Accepted: 04/20/2020] [Indexed: 12/25/2022]
Affiliation(s)
- Jens Habenstein
- Biocenter, Behavioral Physiology and Sociobiology (Zoology II) University of Würzburg Würzburg Germany
| | - Emad Amini
- Biocenter, Neurobiology and Genetics University of Würzburg Würzburg Germany
| | - Kornelia Grübel
- Biocenter, Behavioral Physiology and Sociobiology (Zoology II) University of Würzburg Würzburg Germany
| | - Basil el Jundi
- Biocenter, Behavioral Physiology and Sociobiology (Zoology II) University of Würzburg Würzburg Germany
| | - Wolfgang Rössler
- Biocenter, Behavioral Physiology and Sociobiology (Zoology II) University of Würzburg Würzburg Germany
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27
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Hensgen R, England L, Homberg U, Pfeiffer K. Neuroarchitecture of the central complex in the brain of the honeybee: Neuronal cell types. J Comp Neurol 2020; 529:159-186. [PMID: 32374034 DOI: 10.1002/cne.24941] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 04/30/2020] [Accepted: 04/30/2020] [Indexed: 12/11/2022]
Abstract
The central complex (CX) in the insect brain is a higher order integration center that controls a number of behaviors, most prominently goal directed locomotion. The CX comprises the protocerebral bridge (PB), the upper division of the central body (CBU), the lower division of the central body (CBL), and the paired noduli (NO). Although spatial orientation has been extensively studied in honeybees at the behavioral level, most electrophysiological and anatomical analyses have been carried out in other insect species, leaving the morphology and physiology of neurons that constitute the CX in the honeybee mostly enigmatic. The goal of this study was to morphologically identify neuronal cell types of the CX in the honeybee Apis mellifera. By performing iontophoretic dye injections into the CX, we traced 16 subtypes of neuron that connect a subdivision of the CX with other regions in the bee's central brain, and eight subtypes that mainly interconnect different subdivisions of the CX. They establish extensive connections between the CX and the lateral complex, the superior protocerebrum and the posterior protocerebrum. Characterized neuron classes and subtypes are morphologically similar to those described in other insects, suggesting considerable conservation in the neural network relevant for orientation.
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Affiliation(s)
- Ronja Hensgen
- Animal Physiology, Department of Biology, Philipps-Universität Marburg, Marburg, Germany
| | - Laura England
- Animal Physiology, Department of Biology, Philipps-Universität Marburg, Marburg, Germany
| | - Uwe Homberg
- Animal Physiology, Department of Biology, Philipps-Universität Marburg, Marburg, Germany
| | - Keram Pfeiffer
- Behavioral Physiology and Sociobiology (Zoology II), Biozentrum, University of Würzburg, Würzburg, Germany
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28
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Bates AS, Manton JD, Jagannathan SR, Costa M, Schlegel P, Rohlfing T, Jefferis GSXE. The natverse, a versatile toolbox for combining and analysing neuroanatomical data. eLife 2020; 9:e53350. [PMID: 32286229 PMCID: PMC7242028 DOI: 10.7554/elife.53350] [Citation(s) in RCA: 104] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 04/11/2020] [Indexed: 11/18/2022] Open
Abstract
To analyse neuron data at scale, neuroscientists expend substantial effort reading documentation, installing dependencies and moving between analysis and visualisation environments. To facilitate this, we have developed a suite of interoperable open-source R packages called the natverse. The natverse allows users to read local and remote data, perform popular analyses including visualisation and clustering and graph-theoretic analysis of neuronal branching. Unlike most tools, the natverse enables comparison across many neurons of morphology and connectivity after imaging or co-registration within a common template space. The natverse also enables transformations between different template spaces and imaging modalities. We demonstrate tools that integrate the vast majority of Drosophila neuroanatomical light microscopy and electron microscopy connectomic datasets. The natverse is an easy-to-use environment for neuroscientists to solve complex, large-scale analysis challenges as well as an open platform to create new code and packages to share with the community.
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Affiliation(s)
| | - James D Manton
- Neurobiology Division, MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
| | - Sridhar R Jagannathan
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Marta Costa
- Neurobiology Division, MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Philipp Schlegel
- Neurobiology Division, MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
| | - Torsten Rohlfing
- SRI International, Neuroscience Program, Center for Health SciencesMenlo ParkUnited States
| | - Gregory SXE Jefferis
- Neurobiology Division, MRC Laboratory of Molecular BiologyCambridgeUnited Kingdom
- Drosophila Connectomics Group, Department of Zoology, University of CambridgeCambridgeUnited Kingdom
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29
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Pickard SC, Quinn RD, Szczecinski NS. A dynamical model exploring sensory integration in the insect central complex substructures. BIOINSPIRATION & BIOMIMETICS 2020; 15:026003. [PMID: 31726442 DOI: 10.1088/1748-3190/ab57b6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
It is imperative that an animal has the ability to contextually integrate received sensory information to formulate appropriate behavioral responses. Determining a body heading based on a multitude of ego-motion cues and visual landmarks is an example of such a task that requires this context dependent integration. The work presented here simulates a sensory integrator in the insect brain called the central complex (CX). Based on the architecture of the CX, we assembled a dynamical neural simulation of two structures called the protocerebral bridge (PB) and the ellipsoid body (EB). Using non-spiking neuronal dynamics, our simulation was able to recreate in vivo neuronal behavior such as correlating body rotation direction and speed to activity bumps within the EB as well as updating the believed heading with quick secondary system updates. With this model, we performed sensitivity analysis of certain neuronal parameters as a possible means to control multi-system gains during sensory integration. We found that modulation of synapses in the memory network and EB inhibition are two possible mechanisms in which a sensory system could affect the memory stability and gain of another input, respectively. This model serves as an exploration in network design for integrating simultaneous idiothetic and allothetic cues in the task of body tracking and determining contextually dependent behavioral outputs.
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Affiliation(s)
- S C Pickard
- Author to whom any correspondence should be addressed
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30
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de Andres-Bragado L, Sprecher SG. Mechanisms of vision in the fruit fly. CURRENT OPINION IN INSECT SCIENCE 2019; 36:25-32. [PMID: 31325739 DOI: 10.1016/j.cois.2019.06.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 06/17/2019] [Accepted: 06/21/2019] [Indexed: 06/10/2023]
Abstract
Vision is essential to maximize the efficiency of daily tasks such as feeding, avoiding predators or finding mating partners. An advantageous model is Drosophila melanogaster, since it offers tools that allow genetic and neuronal manipulation with high spatial and temporal resolution, which can be combined with behavioral, anatomical and physiological assays. Recent advances have expanded our knowledge on the neural circuitry underlying such important behaviors as color vision (role of reciprocal inhibition to enhance color signal at the level of the ommatidia); motion vision (motion-detection neurones receive both excitatory and inhibitory input), and sensory processing (role of the central complex in spatial navigation, and in orchestrating the information from other senses and the inner state). Research on synergies between pathways is shaping the field.
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Affiliation(s)
| | - Simon G Sprecher
- Department of Biology, University of Fribourg, Fribourg, Switzerland.
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31
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von Hadeln J, Hensgen R, Bockhorst T, Rosner R, Heidasch R, Pegel U, Quintero Pérez M, Homberg U. Neuroarchitecture of the central complex of the desert locust: Tangential neurons. J Comp Neurol 2019; 528:906-934. [PMID: 31625611 DOI: 10.1002/cne.24796] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 10/10/2019] [Accepted: 10/11/2019] [Indexed: 12/11/2022]
Abstract
The central complex (CX) comprises a group of midline neuropils in the insect brain, consisting of the protocerebral bridge (PB), the upper (CBU) and lower division (CBL) of the central body and a pair of globular noduli. It receives prominent input from the visual system and plays a major role in spatial orientation of the animals. Vertical slices and horizontal layers of the CX are formed by columnar, tangential, and pontine neurons. While pontine and columnar neurons have been analyzed in detail, especially in the fruit fly and desert locust, understanding of the organization of tangential cells is still rudimentary. As a basis for future functional studies, we have studied the morphologies of tangential neurons of the CX of the desert locust Schistocerca gregaria. Intracellular dye injections revealed 43 different types of tangential neuron, 8 of the PB, 5 of the CBL, 24 of the CBU, 2 of the noduli, and 4 innervating multiple substructures. Cell bodies of these neurons were located in 11 different clusters in the cell body rind. Judging from the presence of fine versus beaded terminals, the vast majority of these neurons provide input into the CX, especially from the lateral complex (LX), the superior protocerebrum, the posterior slope, and other surrounding brain areas, but not directly from the mushroom bodies. Connections are largely subunit- and partly layer-specific. No direct connections were found between the CBU and the CBL. Instead, both subdivisions are connected in parallel with the PB and distinct layers of the noduli.
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Affiliation(s)
- Joss von Hadeln
- Fachbereich Biologie, Tierphysiologie, and Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Ronja Hensgen
- Fachbereich Biologie, Tierphysiologie, and Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Tobias Bockhorst
- Fachbereich Biologie, Tierphysiologie, and Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Ronny Rosner
- Fachbereich Biologie, Tierphysiologie, and Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Ronny Heidasch
- Fachbereich Biologie, Tierphysiologie, and Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Uta Pegel
- Fachbereich Biologie, Tierphysiologie, and Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Manuel Quintero Pérez
- Fachbereich Biologie, Tierphysiologie, and Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
| | - Uwe Homberg
- Fachbereich Biologie, Tierphysiologie, and Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus Liebig University Giessen, Germany
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32
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Groothuis J, Pfeiffer K, El Jundi B, Smid HM. The Jewel Wasp Standard Brain: Average shape atlas and morphology of the female Nasonia vitripennis brain. ARTHROPOD STRUCTURE & DEVELOPMENT 2019; 51:41-51. [PMID: 31357033 DOI: 10.1016/j.asd.2019.100878] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 07/25/2019] [Accepted: 07/25/2019] [Indexed: 06/10/2023]
Abstract
Nasonia, a genus of parasitoid wasps, is a promising model system in the study of developmental and evolutionary genetics, as well as complex traits such as learning. Of these "jewel wasps", the species Nasonia vitripennis is widely spread and widely studied. To accelerate neuroscientific research in this model species, fundamental knowledge of its nervous system is needed. To this end, we present an average standard brain of recently eclosed naïve female N. vitripennis wasps obtained by the iterative shape averaging method. This "Jewel Wasp Standard Brain" includes the optic lobe (excluding the lamina), the anterior optic tubercle, the antennal lobe, the lateral horn, the mushroom body, the central complex, and the remaining unclassified neuropils in the central brain. Furthermore, we briefly describe these well-defined neuropils and their subregions in the N. vitripennis brain. A volumetric analysis of these neuropils is discussed in the context of brains of other insect species. The Jewel Wasp Standard Brain will provide a framework to integrate and consolidate the results of future neurobiological studies in N. vitripennis. In addition, the volumetric analysis provides a baseline for future work on age- and experience-dependent brain plasticity.
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Affiliation(s)
- Jitte Groothuis
- Laboratory of Entomology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Keram Pfeiffer
- Behavioral Physiology and Sociobiology (Zoology II), University of Würzburg, Biocenter, Am Hubland, 97074, Würzburg, Germany
| | - Basil El Jundi
- Behavioral Physiology and Sociobiology (Zoology II), University of Würzburg, Biocenter, Am Hubland, 97074, Würzburg, Germany
| | - Hans M Smid
- Laboratory of Entomology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands.
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33
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Abstract
South African ball-rolling dung beetles exhibit a unique orientation behavior to avoid competition for food: after forming a piece of dung into a ball, they efficiently escape with it from the dung pile along a straight-line path. To keep track of their heading, these animals use celestial cues, such as the sun, as an orientation reference. Here we show that wind can also be used as a guiding cue for the ball-rolling beetles. We demonstrate that this mechanosensory compass cue is only used when skylight cues are difficult to read, i.e., when the sun is close to the zenith. This raises the question of how the beetles combine multimodal orientation input to obtain a robust heading estimate. To study this, we performed behavioral experiments in a tightly controlled indoor arena. This revealed that the beetles register directional information provided by the sun and the wind and can use them in a weighted manner. Moreover, the directional information can be transferred between these 2 sensory modalities, suggesting that they are combined in the spatial memory network in the beetle's brain. This flexible use of compass cue preferences relative to the prevailing visual and mechanosensory scenery provides a simple, yet effective, mechanism for enabling precise compass orientation at any time of the day.
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34
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Kamhi JF, Ilieş I, Traniello JFA. Social Complexity and Brain Evolution: Comparative Analysis of Modularity and Integration in Ant Brain Organization. BRAIN, BEHAVIOR AND EVOLUTION 2019; 93:4-18. [PMID: 30982030 DOI: 10.1159/000497267] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Accepted: 01/27/2019] [Indexed: 11/19/2022]
Abstract
The behavioral demands of living in social groups have been linked to the evolution of brain size and structure, but how social organization shapes investment and connectivity within and among functionally specialized brain regions remains unclear. To understand the influence of sociality on brain evolution in ants, a premier clade of eusocial insects, we statistically analyzed patterns of brain region size covariation as a proxy for brain region connectivity. We investigated brain structure covariance in young and old workers of two formicine ants, the Australasian weaver ant Oecophylla smaragdina, a pinnacle of social complexity in insects, and its socially basic sister clade Formica subsericea. As previously identified in other ant species, we predicted that our analysis would recognize in both species an olfaction-related brain module underpinning social information processing in the brain, and a second neuroanatomical cluster involved in nonolfactory sensorimotor processes, thus reflecting conservation of compartmental connectivity. Furthermore, we hypothesized that covariance patterns would reflect divergence in social organization and life histories either within this species pair or compared to other ant species. Contrary to our predictions, our covariance analyses revealed a weakly defined visual, rather than olfactory, sensory processing cluster in both species. This pattern may be linked to the reliance on vision for worker behavioral performance outside of the nest and the correlated expansion of the optic lobes to meet navigational demands in both species. Additionally, we found that colony size and social organization, key measures of social complexity, were only weakly correlated with brain modularity in these formicine ants. Worker age also contributed to variance in brain organization, though in different ways in each species. These findings suggest that brain organization may be shaped by the divergent life histories of the two study species. We compare our findings with patterns of brain organization of other eusocial insects.
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Affiliation(s)
- J Frances Kamhi
- Graduate Program for Neuroscience, Boston University, Boston, Massachusetts, USA, .,Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia,
| | - Iulian Ilieş
- Healthcare Systems Engineering Institute, Department of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts, USA
| | - James F A Traniello
- Graduate Program for Neuroscience, Boston University, Boston, Massachusetts, USA.,Department of Biology, Boston University, Boston, Massachusetts, USA
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35
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El Jundi B, Baird E, Byrne MJ, Dacke M. The brain behind straight-line orientation in dung beetles. ACTA ACUST UNITED AC 2019; 222:222/Suppl_1/jeb192450. [PMID: 30728239 DOI: 10.1242/jeb.192450] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
For many insects, celestial compass cues play an important role in keeping track of their directional headings. One well-investigated group of celestial orientating insects are the African ball-rolling dung beetles. After finding a dung pile, these insects detach a piece, form it into a ball and roll it away along a straight path while facing backwards. A brain region, termed the central complex, acts as an internal compass that constantly updates the ball-rolling dung beetle about its heading. In this review, we give insights into the compass network behind straight-line orientation in dung beetles and place it in the context of the orientation mechanisms and neural networks of other insects. We find that the neuronal network behind straight-line orientation in dung beetles has strong similarities to the ones described in path-integrating and migrating insects, with the central complex being the key control point for this behavior. We conclude that, despite substantial differences in behavior and navigational challenges, dung beetles encode compass information in a similar way to other insects.
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Affiliation(s)
- Basil El Jundi
- University of Wuerzburg, Biocenter, Zoology II, Emmy-Noether Group, 97074 Würzburg, Germany
| | - Emily Baird
- Stockholm University, Faculty of Science, Department of Zoology, Division of Functional Morphology, 10691 Stockholm, Sweden
| | - Marcus J Byrne
- University of the Witwatersrand, School of Animal, Plant and Environmental Sciences, Wits 2050, South Africa
| | - Marie Dacke
- University of the Witwatersrand, School of Animal, Plant and Environmental Sciences, Wits 2050, South Africa.,Lund University, Department of Biology, Lund Vision Group, 22362 Lund, Sweden
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