Mushroom bodies and reniform bodies coexisting in crabs cannot both be homologues of the insect mushroom body

2021 ◽  
Author(s):  
Nicholas J. Strausfeld
Keyword(s):  
Mushroom Body ◽  
Mushroom Bodies

scholarly journals Drosophila mef2 is essential for normal mushroom body and wing development

2018 ◽  
Author(s):  
Jill R. Crittenden ◽  
Efthimios M. C. Skoulakis ◽  
Elliott. S. Goldstein ◽  
Ronald L. Davis
Keyword(s):  
Nuclear Localization ◽  
Mushroom Body ◽  
Normal Development ◽  
Cell Types ◽  
Mushroom Bodies ◽  
Wing Development ◽  
Myocyte Enhancer Factor 2 ◽  
Multiple Cell ◽  
The Brain ◽  
Enhancer Factor

ABSTRACTMEF2 (myocyte enhancer factor 2) transcription factors are found in the brain and muscle of insects and vertebrates and are essential for the differentiation of multiple cell types. We show that in the fruitfly Drosophila, MEF2 is essential for normal development of wing veins, and for mushroom body formation in the brain. In embryos mutant for D-mef2, there was a striking reduction in the number of mushroom body neurons and their axon bundles were not detectable. D-MEF2 expression coincided with the formation of embryonic mushroom bodies and, in larvae, expression onset was confirmed to be in post-mitotic neurons. With a D-mef2 point mutation that disrupts nuclear localization, we find that D-MEF2 is restricted to a subset of Kenyon cells that project to the α/β, and γ axonal lobes of the mushroom bodies, but not to those forming the α’/β’ lobes. Our findings that ancestral mef2 is specifically important in dopamine-receptive neurons has broad implications for its function in mammalian neurocircuits.

scholarly journals Presynaptic developmental plasticity allows robust sparse wiring of the Drosophila mushroom body

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Najia A Elkahlah ◽  
Jackson A Rogow ◽  
Maria Ahmed ◽  
E Josephine Clowney
Keyword(s):  
Mushroom Body ◽  
Developmental Plasticity ◽  
Brain Regions ◽  
Mushroom Bodies ◽  
Set Convergence ◽  
Limited Size ◽  
Sensory Inputs ◽  
Kenyon Cells ◽  
Complex Stimuli ◽  
Developmental Patterning

In order to represent complex stimuli, principle neurons of associative learning regions receive combinatorial sensory inputs. Density of combinatorial innervation is theorized to determine the number of distinct stimuli that can be represented and distinguished from one another, with sparse innervation thought to optimize the complexity of representations in networks of limited size. How the convergence of combinatorial inputs to principle neurons of associative brain regions is established during development is unknown. Here, we explore the developmental patterning of sparse olfactory inputs to Kenyon cells of the Drosophila melanogaster mushroom body. By manipulating the ratio between pre- and post-synaptic cells, we find that postsynaptic Kenyon cells set convergence ratio: Kenyon cells produce fixed distributions of dendritic claws while presynaptic processes are plastic. Moreover, we show that sparse odor responses are preserved in mushroom bodies with reduced cellular repertoires, suggesting that developmental specification of convergence ratio allows functional robustness.

scholarly journals Brain composition in Heliconius butterflies, post-eclosion growth and experience dependent neuropil plasticity

2015 ◽  
Author(s):  
Stephen H Montgomery ◽  
Richard M Merrill ◽  
Swidbert R Ott
Keyword(s):  
Behavioral Ecology ◽  
Neural Development ◽  
Mushroom Body ◽  
Brain Regions ◽  
Mushroom Bodies ◽  
Heliconius Butterflies ◽  
Sensory Adaptations ◽  
Differential Expansion ◽  
The Brain

Behavioral and sensory adaptations are often based in the differential expansion of brain components. These volumetric differences represent changes in investment, processing capacity and/or connectivity, and can be used to investigate functional and evolutionary relationships between different brain regions, and between brain composition and behavioral ecology. Here, we describe the brain composition of two species of Heliconius butterflies, a long-standing study system for investigating ecological adaptation and speciation. We confirm a previous report of striking mushroom body expansion, and explore patterns of post-eclosion growth and experience-dependent plasticity in neural development. This analysis uncovers age- and experience-dependent post-emergence mushroom body growth comparable to that in foraging hymenoptera, but also identifies plasticity in several other neuropil. An interspecific analysis indicates that Heliconius display remarkable levels of investment in mushroom bodies for a lepidopteran, and indeed rank highly compared to other insects. Our analyses lay the foundation for future comparative and experimental analyses that will establish Heliconius as a useful case study in evolutionary neurobiology.

scholarly journals Direct neural pathways convey distinct visual information to Drosophila mushroom bodies

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Katrin Vogt ◽  
Yoshinori Aso ◽  
Toshihide Hige ◽  
Stephan Knapek ◽  
Toshiharu Ichinose ◽  
...  
Keyword(s):  
Visual Information ◽  
Mushroom Body ◽  
Mushroom Bodies ◽  
Small Subset ◽  
Projection Neurons ◽  
Neural Pathways ◽  
Associative Memories ◽  
Visual Projection ◽  
Olfactory Input ◽  
Odor Representation

Previously, we demonstrated that visual and olfactory associative memories of Drosophila share mushroom body (MB) circuits (<xref ref-type="bibr" rid="bib46">Vogt et al., 2014</xref>). Unlike for odor representation, the MB circuit for visual information has not been characterized. Here, we show that a small subset of MB Kenyon cells (KCs) selectively responds to visual but not olfactory stimulation. The dendrites of these atypical KCs form a ventral accessory calyx (vAC), distinct from the main calyx that receives olfactory input. We identified two types of visual projection neurons (VPNs) directly connecting the optic lobes and the vAC. Strikingly, these VPNs are differentially required for visual memories of color and brightness. The segregation of visual and olfactory domains in the MB allows independent processing of distinct sensory memories and may be a conserved form of sensory representations among insects.

Response Characteristics and Identification of Extrinsic Mushroom Body Neurons of the Bee

1979 ◽  
Vol 34 (7-8) ◽  
pp. 612-615 ◽  
Author(s):  
Uwe Homberg ◽  
Joachim Erber
Keyword(s):  
Mushroom Body ◽  
Response Pattern ◽  
Fluorescent Dye ◽  
Mushroom Bodies ◽  
Spontaneous Discharge ◽  
Single Neurons ◽  
Sugar Water ◽  
Response Characteristics ◽  
Sensory Modalities ◽  
Procion Yellow

Abstract The activity of single neurons with constant discharge frequencies in the area around the α-lobe of the mushroom bodies of the bee was recorded intracellularly. The spontaneous discharge frequency of these neurons ranged between 5 and 95 impulses per second. When stimulated, about 80 percent of the neurons responded to at least one of five different sensory modalities: scent; light; air current to the antennae; sugar water applied to the antennae and to the proboscis. 45 percent of the neurons responded to two or more modalities, these multimodal neurons are common in the median protocerebrum of the bee. The differentiated response pattern of the cells does not allow a simple classification. Some of the neurons were identified after the injection of the fluorescent dye Procion yellow. We found 4 neurons with arborizations in the α-lobe and the calyces of the mushroom bodies.

scholarly journals Axonal chemokine-like Orion induces astrocyte infiltration and engulfment during mushroom body neuronal remodeling

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ana Boulanger ◽  
Camille Thinat ◽  
Stephan Züchner ◽  
Lee G. Fradkin ◽  
Hugues Lortat-Jacob ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Nervous System ◽  
Mushroom Body ◽  
Active Role ◽  
Mushroom Bodies ◽  
Axon Pruning ◽  
Neuronal Remodeling ◽  
Neuronal Signal ◽  
And Function ◽  
Fundamental Mechanism

AbstractThe remodeling of neurons is a conserved fundamental mechanism underlying nervous system maturation and function. Astrocytes can clear neuronal debris and they have an active role in neuronal remodeling. Developmental axon pruning ofDrosophilamemory center neurons occurs via a degenerative process mediated by infiltrating astrocytes. However, how astrocytes are recruited to the axons during brain development is unclear. Using an unbiased screen, we identify the gene requirement oforion, encoding for a chemokine-like protein, in the developing mushroom bodies. Functional analysis shows that Orion is necessary for both axonal pruning and removal of axonal debris. Orion performs its functions extracellularly and bears some features common to chemokines, a family of chemoattractant cytokines. We propose that Orion is a neuronal signal that elicits astrocyte infiltration and astrocyte-driven axonal engulfment required during neuronal remodeling in theDrosophiladeveloping brain.

scholarly journals Fine structure of mushroom bodies and the brain in Sthenelais boa (Phyllodocida, Annelida)

Zoomorphology ◽  
2021 ◽  
Author(s):  
Patrick Beckers ◽  
Carla Pein ◽  
Thomas Bartolomaeus
Keyword(s):  
Mushroom Body ◽  
Convergent Evolution ◽  
Small Diameter ◽  
Synaptic Activity ◽  
Mushroom Bodies ◽  
Glia Cells ◽  
Close Relationship ◽  
Body Design ◽  
Morphological Differences ◽  
The Brain

AbstractMushroom bodies are known from annelids and arthropods and were formerly assumed to argue for a close relationship of these two taxa. Since molecular phylogenies univocally show that both taxa belong to two different clades in the bilaterian tree, similarity must either result from convergent evolution or from transformation of an ancestral mushroom body. Any morphological differences in the ultrastructure and composition of mushroom bodies could thus indicate convergent evolution that results from similar functional constraints. We here study the ultrastructure of the mushroom bodies, the glomerular neuropil, glia-cells and the general anatomy of the nervous system in Sthenelais boa. The neuropil of the mushroom bodies is composed of densely packed, small diameter neurites that lack individual or clusterwise glia enwrapping. Neurites of other regions of the brain are much more prominent, are enwrapped by glia-cell processes and thus can be discriminated from the neuropil of the mushroom bodies. The same applies to the respective neuronal somata. The glomerular neuropil of insects and annelids is a region of higher synaptic activity that result in a spheroid appearance of these structures. However, while these structures are sharply delimited from the surrounding neuropil of the brain by glia enwrapping in insects, this is not the case in Sthenelais boa. Although superficially similar, there are anatomical differences in the arrangement of glia-cells in the mushroom bodies and the glomerular neuropil between insects and annelids. Hence, we suppose that the observed differences rather evolved convergently to solve similar functional constrains than by transforming an ancestral mushroom body design.

scholarly journals The incentive circuit: memory dynamics in the mushroom body of Drosophila melanogaster

2021 ◽  
Author(s):  
Evripidis Gkanias ◽  
Li Yan McCurdy ◽  
Michael N Nitabach ◽  
Barbara Webb
Keyword(s):  
Drosophila Melanogaster ◽  
Mushroom Body ◽  
Learning Rule ◽  
Detailed Examination ◽  
Mushroom Bodies ◽  
Short Term ◽  
Output Neurons ◽  
Memory Acquisition ◽  
Exploration Exploitation

Insects adapt their response to stimuli, such as odours, according to their pairing with positive or negative reinforcements, such as sugar or shock. Recent electrophysiological and imaging findings in Drosophila melanogaster allow detailed examination of the neural mechanisms supporting acquisition, forgetting, and assimilation of memories. Drawing on this data, we identify a series of microcircuits within the mushroom bodies that reveal, for each motivational state, three different roles of dopaminergic and mushroom body output neurons in the memory dynamics. These microcircuits share components and form a unified system for rapid memory acquisition, transfer from short-term to long-term, and exploration/exploitation trade-off. We show that combined with a novel biologically plausible learning rule, a computational model of the full circuit reproduces the observed changes in the activity of each of these neurons in conditioning paradigms and can be used for flexible behavioural control.

scholarly journals An insect-like mushroom body in a crustacean brain

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Gabriella Hannah Wolff ◽  
Hanne Halkinrud Thoen ◽  
Justin Marshall ◽  
Marcel E Sayre ◽  
Nicholas James Strausfeld
Keyword(s):  
Spatial Memory ◽  
Learning And Memory ◽  
Sensory Integration ◽  
Mushroom Body ◽  
Convergent Evolution ◽  
Visual Recognition ◽  
Common Ancestor ◽  
Mushroom Bodies ◽  
Morphological Criteria

Mushroom bodies are the iconic learning and memory centers of insects. No previously described crustacean possesses a mushroom body as defined by strict morphological criteria although crustacean centers called hemiellipsoid bodies, which serve functions in sensory integration, have been viewed as evolutionarily convergent with mushroom bodies. Here, using key identifiers to characterize neural arrangements, we demonstrate insect-like mushroom bodies in stomatopod crustaceans (mantis shrimps). More than any other crustacean taxon, mantis shrimps display sophisticated behaviors relating to predation, spatial memory, and visual recognition comparable to those of insects. However, neuroanatomy-based cladistics suggesting close phylogenetic proximity of insects and stomatopod crustaceans conflicts with genomic evidence showing hexapods closely related to simple crustaceans called remipedes. We discuss whether corresponding anatomical phenotypes described here reflect the cerebral morphology of a common ancestor of Pancrustacea or an extraordinary example of convergent evolution.

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