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.

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 Mushroom Body Homology and Divergence across Pancrustacea

2019 ◽  
Author(s):  
Nicholas J. Strausfeld ◽  
Gabriella H. Wolff ◽  
Marcel E. Sayre
Keyword(s):  
Learning And Memory ◽  
Mushroom Body ◽  
Mushroom Bodies ◽  
Ground Pattern ◽  
Olfactory Information ◽  
Columnar Organization ◽  
Spiny Lobsters

AbstractDescriptions of crustacean brains have mainly focused on three highly derived lineages: the reptantian infraorders represented by spiny lobsters, lobsters, and crayfish. Those descriptions advocate the view that dome- or cap-like neuropils, referred to as “hemiellipsoid bodies,” are the ground pattern organization of centers that are comparable to insect mushroom bodies in processing olfactory information. Here we challenge the doctrine that hemiellipsoid bodies are a derived trait of crustaceans, whereas mushroom bodies are a derived trait of hexapods. We demonstrate that mushroom bodies typify lineages that arose before Reptantia and exist in Reptantia. We show that evolved variations of the mushroom body ground pattern are, in some lineages, defined by extreme diminution or loss and, in others, by the incorporation of mushroom body circuits into lobeless centers. Such transformations are ascribed to modifications of the columnar organization of mushroom body lobes that, as shown in Drosophila and other hexapods, contain networks essential for learning and memory. We propose that lobed mushroom bodies distinguish crustaceans that negotiate the multidimensionality of complex ecologies, where continuous updating of multistimulus valence and memory is paramount.

scholarly journals Mushroom body evolution demonstrates homology and divergence across Pancrustacea

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Nicholas James Strausfeld ◽  
Gabriella Hanna Wolff ◽  
Marcel Ethan Sayre
Keyword(s):  
Learning And Memory ◽  
Mushroom Body ◽  
Mushroom Bodies ◽  
Ground Pattern ◽  
Olfactory Information ◽  
Columnar Organization ◽  
Spiny Lobsters ◽  
Hemiellipsoid Body

Descriptions of crustacean brains have focused mainly on three highly derived lineages of malacostracans: the reptantian infraorders represented by spiny lobsters, lobsters, and crayfish. Those descriptions advocate the view that dome- or cap-like neuropils, referred to as ‘hemiellipsoid bodies,’ are the ground pattern organization of centers that are comparable to insect mushroom bodies in processing olfactory information. Here we challenge the doctrine that hemiellipsoid bodies are a derived trait of crustaceans, whereas mushroom bodies are a derived trait of hexapods. We demonstrate that mushroom bodies typify lineages that arose before Reptantia and exist in Reptantia thereby indicating that the mushroom body, not the hemiellipsoid body, provides the ground pattern for both crustaceans and hexapods. We show that evolved variations of the mushroom body ground pattern are, in some lineages, defined by extreme diminution or loss and, in others, by the incorporation of mushroom body circuits into lobeless centers. Such transformations are ascribed to modifications of the columnar organization of mushroom body lobes that, as shown in Drosophila and other hexapods, contain networks essential for learning and memory.

scholarly journals Shore crabs reveal novel evolutionary attributes of the mushroom body

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Nicholas Strausfeld ◽  
Marcel E Sayre
Keyword(s):  
Learning And Memory ◽  
Mushroom Body ◽  
Shore Crab ◽  
Mushroom Bodies ◽  
Evolutionary Trend ◽  
Ground Pattern ◽  
Neural Organization ◽  
Shore Crabs ◽  
Successive Loss ◽  
Lateral Protocerebrum

Neural organization of mushroom bodies is largely consistent across insects, whereas the ancestral ground pattern diverges broadly across crustacean lineages resulting in successive loss of columns and the acquisition of domed centers retaining ancestral Hebbian-like networks and aminergic connections. We demonstrate here a major departure from this evolutionary trend in Brachyura, the most recent malacostracan lineage. In the shore crab Hemigrapsus nudus, instead of occupying the rostral surface of the lateral protocerebrum, mushroom body calyces are buried deep within it with their columns extending outwards to an expansive system of gyri on the brain’s surface. The organization amongst mushroom body neurons reaches extreme elaboration throughout its constituent neuropils. The calyces, columns, and especially the gyri show DC0 immunoreactivity, an indicator of extensive circuits involved in learning and memory.

scholarly journals Shore crabs reveal novel evolutionary attributes of the mushroom body

2020 ◽  
Author(s):  
Nicholas James Strausfeld ◽  
Marcel Ethan Sayre
Keyword(s):  
Learning And Memory ◽  
Mushroom Body ◽  
Mushroom Bodies ◽  
Evolutionary Trend ◽  
Ground Pattern ◽  
Neural Organization ◽  
Shore Crabs ◽  
Successive Loss ◽  
Lateral Protocerebrum

AbstractNeural organization of mushroom bodies is largely consistent across insects, whereas the ancestral ground pattern diverges broadly across crustacean lineages, resulting in successive loss of columns and the acquisition of domed centers retaining ancestral Hebbian-like networks and aminergic connections. We demonstrate here a major departure from this evolutionary trend in Brachyura, the most recent malacostracan lineage. Instead of occupying the rostral surface of the lateral protocerebrum, mushroom body calyces are buried deep within it, with their columns extending outwards to an expansive system of gyri on the brain’s surface. The organization amongst mushroom body neurons reaches extreme elaboration throughout its constituent neuropils. The calyces, columns, and especially the gyri show DC0 immunoreactivity, an indicator of extensive circuits involved in learning and memory.

scholarly journals Reward signaling in a recurrent circuit of dopaminergic neurons and Kenyon cells

2018 ◽  
Author(s):  
Radostina Lyutova ◽  
Maximilian Pfeuffer ◽  
Dennis Segebarth ◽  
Jens Habenstein ◽  
Mareike Selcho ◽  
...  
Keyword(s):  
Learning And Memory ◽  
Dopaminergic Neurons ◽  
Mushroom Body ◽  
Olfactory Learning ◽  
Mushroom Bodies ◽  
Neuronal Circuitry ◽  
Sustained Activity ◽  
Kenyon Cells ◽  
Reward Information ◽  
The Brain

1.AbstractDopaminergic neurons in the brain of theDrosophilalarva play a key role in mediating reward information to the mushroom bodies during appetitive olfactory learning and memory. Using optogenetic activation of Kenyon cells we provide evidence that a functional recurrent signaling loop exists between Kenyon cells and dopaminergic neurons of the primary protocerebral anterior (pPAM) cluster. An optogenetic activation of Kenyon cells paired with an odor is sufficient to induce appetitive memory, while a simultaneous impairment of the dopaminergic pPAM neurons abolishes memory expression. Thus, dopaminergic pPAM neurons mediate reward information to the Kenyon cells, but in turn receive feedback from Kenyon cells. We further show that the activation of recurrent signaling routes within mushroom body circuitry increases the persistence of an odor-sugar memory. Our results suggest that sustained activity in a neuronal circuitry is a conserved mechanism in insects and vertebrates to consolidate memories.

The Drosophila mushroom body is a quadruple structure of clonal units each of which contains a virtually identical set of neurones and glial cells

Development ◽  
1997 ◽  
Vol 124 (4) ◽  
pp. 761-771 ◽  
Author(s):  
K. Ito ◽  
W. Awano ◽  
K. Suzuki ◽  
Y. Hiromi ◽  
D. Yamamoto
Keyword(s):  
Glial Cells ◽  
Sensory Integration ◽  
Mushroom Body ◽  
Expression Patterns ◽  
Cell Lineage ◽  
Cell Types ◽  
Enhancer Trap ◽  
Adult Brain ◽  
A New Technique ◽  
Lineage Analysis

The mushroom body (MB) is an important centre for higher order sensory integration and learning in insects. To analyse the development and organisation of the MB neuropile in Drosophila, we performed cell lineage analysis in the adult brain with a new technique that combines the Flippase (flp)/FRT system and the GAL4/UAS system. We showed that the four mushroom body neuroblasts (MBNbs) give birth exclusively to the neurones and glial cells of the MB, and that each of the four MBNb clones contributes to the entire MB structure. The expression patterns of 19 GAL4 enhancer-trap strains that mark various subsets of MB cells revealed overlapping cell types in all four of the MBNb lineages. Partial ablation of MBNbs using hydroxyurea showed that each of the four neuroblasts autonomously generates the entire repertoire of the known MB substructures.

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