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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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Couto A, Marty S, Dawson EH, d'Ettorre P, Sandoz JC, Montgomery SH. Evolution of the neuronal substrate for kin recognition in social Hymenoptera. Biol Rev Camb Philos Soc 2023; 98:2226-2242. [PMID: 37528574 DOI: 10.1111/brv.13003] [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: 08/11/2022] [Revised: 07/18/2023] [Accepted: 07/20/2023] [Indexed: 08/03/2023]
Abstract
In evolutionary terms, life is about reproduction. Yet, in some species, individuals forgo their own reproduction to support the reproductive efforts of others. Social insect colonies for example, can contain up to a million workers that actively cooperate in tasks such as foraging, brood care and nest defence, but do not produce offspring. In such societies the division of labour is pronounced, and reproduction is restricted to just one or a few individuals, most notably the queen(s). This extreme eusocial organisation exists in only a few mammals, crustaceans and insects, but strikingly, it evolved independently up to nine times in the order Hymenoptera (including ants, bees and wasps). Transitions from a solitary lifestyle to an organised society can occur through natural selection when helpers obtain a fitness benefit from cooperating with kin, owing to the indirect transmission of genes through siblings. However, this process, called kin selection, is vulnerable to parasitism and opportunistic behaviours from unrelated individuals. An ability to distinguish kin from non-kin, and to respond accordingly, could therefore critically facilitate the evolution of eusociality and the maintenance of non-reproductive workers. The question of how the hymenopteran brain has adapted to support this function is therefore a fundamental issue in evolutionary neuroethology. Early neuroanatomical investigations proposed that social Hymenoptera have expanded integrative brain areas due to selection for increased cognitive capabilities in the context of processing social information. Later studies challenged this assumption and instead pointed to an intimate link between higher social organisation and the existence of developed sensory structures involved in recognition and communication. In particular, chemical signalling of social identity, known to be mediated through cuticular hydrocarbons (CHCs), may have evolved hand in hand with a specialised chemosensory system in Hymenoptera. Here, we compile the current knowledge on this recognition system, from emitted identity signals, to the molecular and neuronal basis of chemical detection, with particular emphasis on its evolutionary history. Finally, we ask whether the evolution of social behaviour in Hymenoptera could have driven the expansion of their complex olfactory system, or whether the early origin and conservation of an olfactory subsystem dedicated to social recognition could explain the abundance of eusocial species in this insect order. Answering this question will require further comparative studies to provide a comprehensive view on lineage-specific adaptations in the olfactory pathway of Hymenoptera.
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Affiliation(s)
- Antoine Couto
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
- Evolution, Genomes, Behaviour and Ecology (UMR 9191), IDEEV, Université Paris-Saclay, CNRS, IRD, 12 route 128, Gif-sur-Yvette, 91190, France
| | - Simon Marty
- Evolution, Genomes, Behaviour and Ecology (UMR 9191), IDEEV, Université Paris-Saclay, CNRS, IRD, 12 route 128, Gif-sur-Yvette, 91190, France
| | - Erika H Dawson
- Laboratory of Experimental and Comparative Ethology, UR 4443 (LEEC), Université Sorbonne Paris Nord, 99 avenue J.-B. Clément, Villetaneuse, 93430, France
| | - Patrizia d'Ettorre
- Laboratory of Experimental and Comparative Ethology, UR 4443 (LEEC), Université Sorbonne Paris Nord, 99 avenue J.-B. Clément, Villetaneuse, 93430, France
- Institut Universitaire de France (IUF), 103 Boulevard Saint-Michel, Paris, 75005, France
| | - Jean-Christophe Sandoz
- Evolution, Genomes, Behaviour and Ecology (UMR 9191), IDEEV, Université Paris-Saclay, CNRS, IRD, 12 route 128, Gif-sur-Yvette, 91190, France
| | - Stephen H Montgomery
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
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Watanabe H, Tateishi K. Parallel olfactory processing in a hemimetabolous insect. CURRENT OPINION IN INSECT SCIENCE 2023; 59:101097. [PMID: 37541388 DOI: 10.1016/j.cois.2023.101097] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/25/2023] [Accepted: 07/30/2023] [Indexed: 08/06/2023]
Abstract
To represent specific olfactory cues from the highly complex and dynamic odor world in the brain, insects employ multiple parallel olfactory pathways that process odors with different coding strategies. Here, we summarize the anatomical and physiological features of parallel olfactory pathways in the hemimetabolous insect, the cockroach Periplaneta americana. The cockroach processes different aspects of odor stimuli, such as odor qualities, temporal information, and dynamics, through parallel olfactory pathways. These parallel pathways are anatomically segregated from the peripheral to higher brain centers, forming functional maps within the brain. In addition, the cockroach may possess parallel pathways that correspond to distinct types of olfactory receptors expressed in sensory neurons. Through comparisons with olfactory pathways in holometabolous insects, we aim to provide valuable insights into the organization, functionality, and evolution of insect olfaction.
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Affiliation(s)
- Hidehiro Watanabe
- Department of Earth System Science, Faculty of Science, Fukuoka University, Fukuoka 814-0180, Fukuoka, Japan.
| | - Kosuke Tateishi
- Department of Earth System Science, Faculty of Science, Fukuoka University, Fukuoka 814-0180, Fukuoka, Japan; School of Biological and Environmental Sciences, Kwansei Gakuin University, Sanda 669-1330, Hyogo, Japan
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4
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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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Separate But Interactive Parallel Olfactory Processing Streams Governed by Different Types of GABAergic Feedback Neurons in the Mushroom Body of a Basal Insect. J Neurosci 2019; 39:8690-8704. [PMID: 31548236 DOI: 10.1523/jneurosci.0088-19.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 09/08/2019] [Accepted: 09/17/2019] [Indexed: 11/21/2022] Open
Abstract
The basic organization of the olfactory system has been the subject of extensive studies in vertebrates and invertebrates. In many animals, GABA-ergic neurons inhibit spike activities of higher-order olfactory neurons and help sparsening of their odor representations. In the cockroach, two different types of GABA-immunoreactive interneurons (calyceal giants [CGs]) mainly project to the base and lip regions of the calyces (input areas) of the mushroom body (MB), a second-order olfactory center. The base and lip regions receive axon terminals of two different types of projection neurons, which receive synapses from different classes of olfactory sensory neurons (OSNs), and receive dendrites of different classes of Kenyon cells, MB intrinsic neurons. We performed intracellular recordings from pairs of CGs and MB output neurons (MBONs) of male American cockroaches, the latter receiving synapses from Kenyon cells, and we found that a CG receives excitatory synapses from an MBON and that odor responses of the MBON are changed by current injection into the CG. Such feedback effects, however, were often weak or absent in pairs of neurons that belong to different streams, suggesting parallel organization of the recurrent pathways, although interactions between different streams were also evident. Cross-covariance analysis of the spike activities of CGs and MBONs suggested that odor stimulation produces synchronized spike activities in MBONs and then in CGs. We suggest that there are separate but interactive parallel streams to process odors detected by different OSNs throughout the olfactory processing system in cockroaches.SIGNIFICANCE STATEMENT Organizational principles of the olfactory system have been the subject of extensive studies. In cockroaches, signals from olfactory sensory neurons (OSNs) in two different classes of sensilla are sent to two different classes of projection neurons, which terminate in different areas of the mushroom body (MB), each area having dendrites of different classes of MB intrinsic neurons (Kenyon cells) and terminations of different classes of GABAergic neurons. Physiological and morphological assessments derived from simultaneous intracellular recordings/stainings from GABAergic neurons and MB output neurons suggested that GABAergic neurons play feedback roles and that odors detected by OSNs are processed in separate but interactive processing streams throughout the central olfactory system.
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Watanabe H, Nishino H, Mizunami M, Yokohari F. Two Parallel Olfactory Pathways for Processing General Odors in a Cockroach. Front Neural Circuits 2017; 11:32. [PMID: 28529476 PMCID: PMC5418552 DOI: 10.3389/fncir.2017.00032] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/18/2017] [Indexed: 11/23/2022] Open
Abstract
In animals, sensory processing via parallel pathways, including the olfactory system, is a common design. However, the mechanisms that parallel pathways use to encode highly complex and dynamic odor signals remain unclear. In the current study, we examined the anatomical and physiological features of parallel olfactory pathways in an evolutionally basal insect, the cockroach Periplaneta americana. In this insect, the entire system for processing general odors, from olfactory sensory neurons to higher brain centers, is anatomically segregated into two parallel pathways. Two separate populations of secondary olfactory neurons, type1 and type2 projection neurons (PNs), with dendrites in distinct glomerular groups relay olfactory signals to segregated areas of higher brain centers. We conducted intracellular recordings, revealing olfactory properties and temporal patterns of both types of PNs. Generally, type1 PNs exhibit higher odor-specificities to nine tested odorants than type2 PNs. Cluster analyses revealed that odor-evoked responses were temporally complex and varied in type1 PNs, while type2 PNs exhibited phasic on-responses with either early or late latencies to an effective odor. The late responses are 30–40 ms later than the early responses. Simultaneous intracellular recordings from two different PNs revealed that a given odor activated both types of PNs with different temporal patterns, and latencies of early and late responses in type2 PNs might be precisely controlled. Our results suggest that the cockroach is equipped with two anatomically and physiologically segregated parallel olfactory pathways, which might employ different neural strategies to encode odor information.
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Affiliation(s)
- Hidehiro Watanabe
- Division of Biology, Department of Earth System Science, Fukuoka UniversityFukuoka, Japan
| | - Hiroshi Nishino
- Research Institute for Electronic Science, Hokkaido UniversitySapporo, Japan
| | | | - Fumio Yokohari
- Division of Biology, Department of Earth System Science, Fukuoka UniversityFukuoka, Japan
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7
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Kinoshita M, Homberg U. Insect Brains: Minute Structures Controlling Complex Behaviors. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/978-4-431-56469-0_6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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8
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Hosono S, Matsumoto Y, Mizunami M. Interaction of inhibitory and facilitatory effects of conditioning trials on long-term memory formation. ACTA ACUST UNITED AC 2016; 23:669-678. [PMID: 27918270 PMCID: PMC5110985 DOI: 10.1101/lm.043513.116] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Accepted: 08/17/2016] [Indexed: 01/27/2023]
Abstract
Animals learn through experience and consolidate the memories into long-time storage. Conditioning parameters to induce protein synthesis-dependent long-term memory (LTM) have been the subject of extensive studies in many animals. Here we found a case in which a conditioning trial inhibits or facilitates LTM formation depending on the intervals from preceding trials. We studied the effects of conditioning parameters on LTM formation in olfactory conditioning of maxillary-palpi extension response with sucrose reward in the cockroach Periplaneta americana. We found, at first, that translation- and transcription-dependent LTM forms 1 h after training, the fastest so far reported in insects. Second, we observed that multiple-trial training with an intertrial interval (ITI) of 20 or 30 sec, often called massed training, is more effective than spaced training for LTM formation, an observation that differs from the results of most studies in other animals. Third, we found that a conditioning trial inhibits LTM formation when the intervals from preceding trials were in the range of 10–16 min. This inhibitory effect is pairing-specific and is not due to decreased motivation for learning (overtraining effect). To our knowledge, no similar inhibition of LTM formation by a conditioning trial has been reported in any animals. We propose a model to account for the effects of trial number and ITIs on LTM formation. Olfactory conditioning in cockroaches should provide pertinent materials in which to study neuronal and molecular mechanisms underlying the inhibitory and facilitatory processes for LTM formation.
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Affiliation(s)
- Shouhei Hosono
- Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan.,Graduate School of Agriculture, Tamagawa University, Machida 194-8610, Japan
| | - Yukihisa Matsumoto
- Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.,Faculty of Liberal Arts, Tokyo Medical and Dental University, Ichikawa 272-0827, Japan
| | - Makoto Mizunami
- Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
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Takahashi N, Katoh K, Watanabe H, Nakayama Y, Iwasaki M, Mizunami M, Nishino H. Complete identification of four giant interneurons supplying mushroom body calyces in the cockroach Periplaneta americana. J Comp Neurol 2016; 525:204-230. [PMID: 27573362 DOI: 10.1002/cne.24108] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 08/04/2016] [Accepted: 08/05/2016] [Indexed: 10/21/2022]
Abstract
Global inhibition is a fundamental physiological mechanism that has been proposed to shape odor representation in higher-order olfactory centers. A pair of mushroom bodies (MBs) in insect brains, an analog of the mammalian olfactory cortex, are implicated in multisensory integration and associative memory formation. With the use of single/multiple intracellular recording and staining in the cockroach Periplaneta americana, we succeeded in unambiguous identification of four tightly bundled GABA-immunoreactive giant interneurons that are presumably involved in global inhibitory control of the MB. These neurons, including three spiking neurons and one nonspiking neuron, possess dendrites in termination fields of MB output neurons and send axon terminals back to MB input sites, calyces, suggesting feedback roles onto the MB. The largest spiking neuron innervates almost exclusively the basal region of calyces, while the two smaller spiking neurons and the second-largest nonspiking neuron innervate more profusely the peripheral (lip) region of the calyces than the basal region. This subdivision corresponds well to the calycal zonation made by axon terminals of two populations of uniglomerular projection neurons with dendrites in distinct glomerular groups in the antennal lobe. The four giant neurons exhibited excitatory responses to every odor tested in a neuron-specific fashion, and two of the neurons also exhibited inhibitory responses in some recording sessions. Our results suggest that two parallel olfactory inputs to the MB undergo different forms of inhibitory control by the giant neurons, which may, in turn, be involved in different aspects of odor discrimination, plasticity, and state-dependent gain control. J. Comp. Neurol. 525:204-230, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Naomi Takahashi
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan
| | - Ko Katoh
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan
| | - Hidehiro Watanabe
- Division of Biology, Department of Earth System Science, Fukuoka University, Fukuoka, Japan
| | - Yuta Nakayama
- Graduate School of Life Science, Hokkaido University, Sapporo, Japan
| | - Masazumi Iwasaki
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
| | | | - Hiroshi Nishino
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
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10
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Schürmann FW. Fine structure of synaptic sites and circuits in mushroom bodies of insect brains. ARTHROPOD STRUCTURE & DEVELOPMENT 2016; 45:399-421. [PMID: 27555065 DOI: 10.1016/j.asd.2016.08.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 07/01/2016] [Accepted: 08/05/2016] [Indexed: 06/06/2023]
Abstract
In the insect brain, mushroom bodies represent a prominent central neuropil for multisensory integration and, crucially, for learning and memory. For this reason, special attention has been focused on its small chemical synapses. Early studies on synaptic types and their distribution, using conventional electron microscopy, and recent publications have resolved basic features of synaptic circuits. More recent studies, using experimental methods for resolving neurons, such as immunocytochemistry, genetic labelling, high resolution confocal microscopy and more advanced electron microscopy, have revealed many new details about the fine structure and molecular contents of identifiable neurons of mushroom bodies and has led to more refined modelling of functional organisation. Synaptic circuitries have been described in most detail for the calyces. In contrast, the mushroom bodies' columnar peduncle and lobes have been explored to a lesser degree. In dissecting local microcircuits, the scientist is confronted with complex neuronal compartmentalisation and specific synaptic arrangements. This article reviews classical and modern studies on the fine structure of synapses and their networks in mushroom bodies across several insect species.
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Affiliation(s)
- Friedrich-Wilhelm Schürmann
- Johann-Friedrich-Blumenbach Institut für Zoologie und Anthropologie, Georg-August-University Göttingen, Berlinerstrasse 28, D-37073 Göttingen, Germany.
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Abstract
Large, complex brains have evolved independently in several lineages of protostomes and deuterostomes. Sensory centres in the brain increase in size and complexity in proportion to the importance of a particular sensory modality, yet often share circuit architecture because of constraints in processing sensory inputs. The selective pressures driving enlargement of higher, integrative brain centres has been more difficult to determine, and may differ across taxa. The capacity for flexible, innovative behaviours, including learning and memory and other cognitive abilities, is commonly observed in animals with large higher brain centres. Other factors, such as social grouping and interaction, appear to be important in a more limited range of taxa, while the importance of spatial learning may be a common feature in insects with large higher brain centres. Despite differences in the exact behaviours under selection, evolutionary increases in brain size tend to derive from common modifications in development and generate common architectural features, even when comparing widely divergent groups such as vertebrates and insects. These similarities may in part be influenced by the deep homology of the brains of all Bilateria, in which shared patterns of developmental gene expression give rise to positionally, and perhaps functionally, homologous domains. Other shared modifications of development appear to be the result of homoplasy, such as the repeated, independent expansion of neuroblast numbers through changes in genes regulating cell division. The common features of large brains in so many groups of animals suggest that given their common ancestry, a limited set of mechanisms exist for increasing structural and functional diversity, resulting in many instances of homoplasy in bilaterian nervous systems.
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Affiliation(s)
- Sarah M Farris
- Department of Biology, West Virginia University, 3139 Life Sciences Building, 53 Campus Drive, Morgantown, WV 26505, USA
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12
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Dopamine- and Tyrosine Hydroxylase-Immunoreactive Neurons in the Brain of the American Cockroach, Periplaneta americana. PLoS One 2016; 11:e0160531. [PMID: 27494326 PMCID: PMC4975486 DOI: 10.1371/journal.pone.0160531] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Accepted: 07/19/2016] [Indexed: 11/19/2022] Open
Abstract
The catecholamine dopamine plays several vital roles in the central nervous system of many species, but its neural mechanisms remain elusive. Detailed neuroanatomical characterization of dopamine neurons is a prerequisite for elucidating dopamine’s actions in the brain. In the present study, we investigated the distribution of dopaminergic neurons in the brain of the American cockroach, Periplaneta americana, using two antisera: 1) an antiserum against dopamine, and 2) an antiserum against tyrosine hydroxylase (TH, an enzyme required for dopamine synthesis), and identified about 250 putatively dopaminergic neurons. The patterns of dopamine- and TH-immunoreactive neurons were strikingly similar, suggesting that both antisera recognize the same sets of “dopaminergic” neurons. The dopamine and TH antibodies intensively or moderately immunolabeled prominent brain neuropils, e.g. the mushroom body (memory center), antennal lobe (first-order olfactory center) and central complex (motor coordination center). All subdivisions of the mushroom body exhibit both dopamine and TH immunoreactivity. Comparison of immunolabeled neurons with those filled by dye injection revealed that a group of immunolabeled neurons with cell bodies near the calyx projects into a distal region of the vertical lobe, which is a plausible site for olfactory memory formation in insects. In the antennal lobe, ordinary glomeruli as well as macroglomeruli exhibit both dopamine and TH immunoreactivity. It is noteworthy that the dopamine antiserum labeled tiny granular structures inside the glomeruli whereas the TH antiserum labeled processes in the marginal regions of the glomeruli, suggesting a different origin. In the central complex, all subdivisions excluding part of the noduli and protocerebral bridge exhibit both dopamine and TH immunoreactivity. These anatomical findings will accelerate our understanding of dopaminergic systems, specifically in neural circuits underlying aversive memory formation and arousal, in insects.
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13
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Yagi R, Mabuchi Y, Mizunami M, Tanaka NK. Convergence of multimodal sensory pathways to the mushroom body calyx in Drosophila melanogaster. Sci Rep 2016; 6:29481. [PMID: 27404960 PMCID: PMC4941532 DOI: 10.1038/srep29481] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 06/20/2016] [Indexed: 12/02/2022] Open
Abstract
Detailed structural analyses of the mushroom body which plays critical roles in olfactory learning and memory revealed that it is directly connected with multiple primary sensory centers in Drosophila. Connectivity patterns between the mushroom body and primary sensory centers suggest that each mushroom body lobe processes information on different combinations of multiple sensory modalities. This finding provides a novel focus of research by Drosophila genetics for perception of the external world by integrating multisensory signals.
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Affiliation(s)
- Ryosuke Yagi
- Graduate School of Life Sciences, Hokkaido University, Sapporo, Japan
| | - Yuta Mabuchi
- Department of Biological Sciences, Hokkaido University, Sapporo, Japan
| | | | - Nobuaki K Tanaka
- Creative Research Institution, Hokkaido University, Sapporo, Japan.,Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Saitama, Japan
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14
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Farris SM. Insect societies and the social brain. CURRENT OPINION IN INSECT SCIENCE 2016; 15:1-8. [PMID: 27436726 DOI: 10.1016/j.cois.2016.01.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 01/26/2016] [Accepted: 01/29/2016] [Indexed: 06/06/2023]
Abstract
The 'social brain hypothesis,' the relationship between social behavior and brain size, does not apply to insects. In social insects, especially those of the Order Hymenoptera (ants, bees and wasps), sociality has not always increased individual behavioral repertoires and is associated with only subtle variation in the size of a higher brain center, the mushroom bodies. Rather than sociality, selection for novel visual behavior, perhaps spatial learning, has led to the acquisition of novel visual inputs and profound increases in mushroom body size. This occurred in nonsocial ancestors suggesting that the sensory and cognitive advantages of large mushroom bodies may be preadaptations to sociality. Adaptations of the insect mushroom bodies are more reliably associated with sensory ecology than social behavior.
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Affiliation(s)
- Sarah M Farris
- Department of Biology, West Virginia University, 3139 Life Sciences Building, 53 Campus Drive, Morgantown, WV 26506, USA.
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Differential investment in visual and olfactory brain areas reflects behavioural choices in hawk moths. Sci Rep 2016; 6:26041. [PMID: 27185464 PMCID: PMC4869021 DOI: 10.1038/srep26041] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 04/26/2016] [Indexed: 11/08/2022] Open
Abstract
Nervous tissue is one of the most metabolically expensive animal tissues, thus evolutionary investments that result in enlarged brain regions should also result in improved behavioural performance. Indeed, large-scale comparative studies in vertebrates and invertebrates have successfully linked differences in brain anatomy to differences in ecology and behaviour, but their precision can be limited by the detail of the anatomical measurements, or by only measuring behaviour indirectly. Therefore, detailed case studies are valuable complements to these investigations, and have provided important evidence linking brain structure to function in a range of higher-order behavioural traits, such as foraging experience or aggressive behaviour. Here, we show that differences in the size of both lower and higher-order sensory brain areas reflect differences in the relative importance of these senses in the foraging choices of hawk moths, as suggested by previous anatomical work in Lepidopterans. To this end we combined anatomical and behavioural quantifications of the relative importance of vision and olfaction in two closely related hawk moth species. We conclude that differences in sensory brain volume in these hawk moths can indeed be interpreted as differences in the importance of these senses for the animal’s behaviour.
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Kinoshita M, Shimohigasshi M, Tominaga Y, Arikawa K, Homberg U. Topographically distinct visual and olfactory inputs to the mushroom body in the Swallowtail butterfly,Papilio xuthus. J Comp Neurol 2014; 523:162-82. [DOI: 10.1002/cne.23674] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 09/05/2014] [Accepted: 09/05/2014] [Indexed: 11/08/2022]
Affiliation(s)
- Michiyo Kinoshita
- Laboratory of Neuroethology; Sokendai-Hayama (The Graduate University for Advanced Studies); Shonan Village Hayama 240-0193 Japan
| | - Miki Shimohigasshi
- Department of Earth System of Science, Faculty of Science; Fukuoka University; Fukuoka 814-0180 Japan
| | - Yoshiya Tominaga
- Department of Earth System of Science, Faculty of Science; Fukuoka University; Fukuoka 814-0180 Japan
| | - Kentaro Arikawa
- Laboratory of Neuroethology; Sokendai-Hayama (The Graduate University for Advanced Studies); Shonan Village Hayama 240-0193 Japan
| | - Uwe Homberg
- Department of Biology, Animal Physiology; University of Marburg; D-35032 Marburg Germany
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Titlow JS, Majeed ZR, Hartman HB, Burns E, Cooper RL. Neural circuit recording from an intact cockroach nervous system. J Vis Exp 2013:e50584. [PMID: 24300738 PMCID: PMC3969889 DOI: 10.3791/50584] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The cockroach ventral nerve cord preparation is a tractable system for neuroethology experiments, neural network modeling, and testing the physiological effects of insecticides. This article describes the scope of cockroach sensory modalities that can be used to assay how an insect nervous system responds to environmental perturbations. Emphasis here is on the escape behavior mediated by cerci to giant fiber transmission in Periplaneta americana. This in situ preparation requires only moderate dissecting skill and electrophysiological expertise to generate reproducible recordings of neuronal activity. Peptides or other chemical reagents can then be applied directly to the nervous system in solution with the physiological saline. Insecticides could also be administered prior to dissection and the escape circuit can serve as a proxy for the excitable state of the central nervous system. In this context the assays described herein would also be useful to researchers interested in limb regeneration and the evolution of nervous system development for which P. americana is an established model organism.
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18
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Namiki S, Takaguchi M, Seki Y, Kazawa T, Fukushima R, Iwatsuki C, Kanzaki R. Concentric zones for pheromone components in the mushroom body calyx of the moth brain. J Comp Neurol 2013; 521:1073-92. [PMID: 22911613 DOI: 10.1002/cne.23219] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Revised: 05/26/2012] [Accepted: 08/17/2012] [Indexed: 12/15/2022]
Abstract
The spatial distribution of input and output neurons in the mushroom body (MB) calyx was investigated in the silkmoth Bombyx mori. In Lepidoptera, the brain has a specialized system for processing sex pheromones. How individual pheromone components are represented in the MB has not yet been elucidated. Toward this end, we first compared the distribution of the presynaptic boutons of antennal lobe projection neurons (PNs), which transfer odor information from the antennal lobe to the MB calyx. The axons of PNs that innervate pheromonal glomeruli were confined to a relatively small area within the calyx. In contrast, the axons of PNs that innervate nonpheromonal glomeruli were more widely distributed. PN axons for the minor pheromone component covered a larger area than those for the major pheromone component and partially overlapped with those innervating nonpheromonal glomeruli, suggesting the integration of the minor pheromone component with plant odors. Overall, we found that PN axons innervating pheromonal and nonpheromonal glomeruli were organized into concentric zones. We then analyzed the dendritic fields of Kenyon cells (KCs), which receive inputs from PNs. Despite the strong regional localization of axons of different PN classes, the dendrites of KCs were less well classified. Finally, we estimated the connectivity between PNs and KCs and suggest that the dendritic field may be organized to receive different amounts of pheromonal and nonpheromonal inputs. PNs for multiple pheromone components and plant odors enter the calyx in a concentric fashion, and they are read out by the elaborate dendritic field of KCs.
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Affiliation(s)
- Shigehiro Namiki
- Intelligent Cooperative Systems Laboratory, Research Center for Advanced Science and Technology, University of Tokyo, Tokyo 153-8904, Japan
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Ito E, Matsuo R, Okada R. Involvement of nitric oxide in memory formation in microbrains. Neurosci Lett 2013; 541:1-3. [PMID: 23473717 DOI: 10.1016/j.neulet.2013.02.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 02/11/2013] [Indexed: 01/09/2023]
Affiliation(s)
- Etsuro Ito
- Laboratory of Functional Biology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, 1314-1 Shido, Sanuki, Kagawa 769-2193, Japan.
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Lin C, Strausfeld NJ. Visual inputs to the mushroom body calyces of the whirligig beetle Dineutus sublineatus: Modality switching in an insect. J Comp Neurol 2012. [DOI: 10.1002/cne.23092] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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21
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Heuer CM, Kollmann M, Binzer M, Schachtner J. Neuropeptides in insect mushroom bodies. ARTHROPOD STRUCTURE & DEVELOPMENT 2012; 41:199-226. [PMID: 22401884 DOI: 10.1016/j.asd.2012.02.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 02/22/2012] [Accepted: 02/23/2012] [Indexed: 05/31/2023]
Abstract
Owing to their experimental amenability, insect nervous systems continue to be in the foreground of investigations into information processing in - ostensibly - simple neuronal networks. Among the cerebral neuropil regions that hold a particular fascination for neurobiologists are the paired mushroom bodies, which, despite their function in other behavioral contexts, are most renowned for their role in learning and memory. The quest to understand the processes that underlie these capacities has been furthered by research focusing on unraveling neuroanatomical connections of the mushroom bodies and identifying key players that characterize the molecular machinery of mushroom body neurons. However, on a cellular level, communication between intrinsic and extrinsic mushroom body neurons still remains elusive. The present account aims to provide an overview on the repertoire of neuropeptides expressed in and utilized by mushroom body neurons. Existing data for a number of insect representatives is compiled and some open gaps in the record are filled by presenting additional original data.
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Affiliation(s)
- Carsten M Heuer
- Philipps-University Marburg, Department of Biology, Animal Physiology, Marburg, Germany.
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Möller R. A model of ant navigation based on visual prediction. J Theor Biol 2012; 305:118-30. [PMID: 22554981 DOI: 10.1016/j.jtbi.2012.04.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 04/12/2012] [Accepted: 04/17/2012] [Indexed: 10/28/2022]
Abstract
A model of visual navigation in ants is presented which is based on a simple network predicting the changes of a visual scene under translatory movements. The model contains two behavioral components: the acquisition of multiple snapshots in different orientations during a learning walk, and the selection of a movement direction by a scanning behavior where the ant searches through different headings. Both components fit with observations in experiments with desert ants. The model is in most aspects biologically plausible with respect to the equivalent neural networks, and it produces reliable homing behavior in a simulated environment with a complex random surface texture. The model is closely related to the algorithmic min-warping method for visual robot navigation which shows good homing performance in real-world environments.
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Affiliation(s)
- Ralf Möller
- Computer Engineering, Faculty of Technology and Center of Excellence Cognitive Interaction Technology, Bielefeld University, POB 10 01 31, 33501 Bielefeld, Germany.
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