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 Location Matters: Navigating Regional Heterogeneity of the Neurovascular Unit

2021 ◽  
Vol 15 ◽  
Author(s):  
Louis-Philippe Bernier ◽  
Clément Brunner ◽  
Azzurra Cottarelli ◽  
Matilde Balbi
Keyword(s):  
Brain Function ◽  
Energy Demand ◽  
Neurovascular Unit ◽  
Cell Types ◽  
Brain Regions ◽  
Regional Heterogeneity ◽  
Regional Specialization ◽  
Multiple Cell ◽  
Cellular Components ◽  
The Brain

The neurovascular unit (NVU) of the brain is composed of multiple cell types that act synergistically to modify blood flow to locally match the energy demand of neural activity, as well as to maintain the integrity of the blood-brain barrier (BBB). It is becoming increasingly recognized that the functional specialization, as well as the cellular composition of the NVU varies spatially. This heterogeneity is encountered as variations in vascular and perivascular cells along the arteriole-capillary-venule axis, as well as through differences in NVU composition throughout anatomical regions of the brain. Given the wide variations in metabolic demands between brain regions, especially those of gray vs. white matter, the spatial heterogeneity of the NVU is critical to brain function. Here we review recent evidence demonstrating regional specialization of the NVU between brain regions, by focusing on the heterogeneity of its individual cellular components and briefly discussing novel approaches to investigate NVU diversity.

scholarly journals Single circuit in V1 capable of switching contexts during movement using VIP population as a switch

2020 ◽  
Author(s):  
Doris Voina ◽  
Stefano Recanatesi ◽  
Brian Hu ◽  
Eric Shea-Brown ◽  
Stefan Mihalas
Keyword(s):  
Visual System ◽  
Visual Processing ◽  
Visual Space ◽  
Cell Types ◽  
Flexible Architecture ◽  
Multiple Cell ◽  
Context Dependent ◽  
Spatio Temporal ◽  
Context Integration ◽  
The Brain

AbstractAs animals adapt to their environments, their brains are tasked with processing stimuli in different sensory contexts. Whether these computations are context dependent or independent, they are all implemented in the same neural tissue. A crucial question is what neural architectures can respond flexibly to a range of stimulus conditions and switch between them. This is a particular case of flexible architecture that permits multiple related computations within a single circuit.Here, we address this question in the specific case of the visual system circuitry, focusing on context integration, defined as the integration of feedforward and surround information across visual space. We show that a biologically inspired microcircuit with multiple inhibitory cell types can switch between visual processing of the static context and the moving context. In our model, the VIP population acts as the switch and modulates the visual circuit through a disinhibitory motif. Moreover, the VIP population is efficient, requiring only a relatively small number of neurons to switch contexts. This circuit eliminates noise in videos by using appropriate lateral connections for contextual spatio-temporal surround modulation, having superior denoising performance compared to circuits where only one context is learned. Our findings shed light on a minimally complex architecture that is capable of switching between two naturalistic contexts using few switching units.Author SummaryThe brain processes information at all times and much of that information is context-dependent. The visual system presents an important example: processing is ongoing, but the context changes dramatically when an animal is still vs. running. How is context-dependent information processing achieved? We take inspiration from recent neurophysiology studies on the role of distinct cell types in primary visual cortex (V1).We find that relatively few “switching units” — akin to the VIP neuron type in V1 in that they turn on and off in the running vs. still context and have connections to and from the main population — is sufficient to drive context dependent image processing. We demonstrate this in a model of feature integration, and in a test of image denoising. The underlying circuit architecture illustrates a concrete computational role for the multiple cell types under increasing study across the brain, and may inspire more flexible neurally inspired computing architectures.

scholarly journals Revealing RCOR2 as a regulatory component of nuclear speckles

2021 ◽  
Author(s):  
Carlos Rivera ◽  
Daniel Verbel ◽  
Duxan Arancibia ◽  
Anna Lappala ◽  
Marcela González ◽  
...  
Keyword(s):  
System Development ◽  
Cell Types ◽  
Nervous System Development ◽  
Nuclear Bodies ◽  
Nuclear Speckles ◽  
Nuclear Speckle ◽  
Multiple Cell ◽  
Rna Maturation ◽  
Nuclear Processes ◽  
The Brain

Abstract Background Nuclear processes such as transcription and RNA maturation can be impacted by subnuclear compartmentalization in condensates and nuclear bodies. Here we characterize the nature of nuclear granules formed by REST corepressor 2 (RCOR2), a nuclear protein essential for pluripotency maintenance and central nervous system development. Results Using biochemical approaches and high-resolution microscopy, we reveal that RCOR2 is localized in nuclear speckles across multiple cell types, including neurons in the brain. RCOR2 forms complexes with nuclear speckle components such as SON, SRSF7, and SRRM2. When cells are exposed to chemical stress, RCOR2 behaves as a core component of the nuclear speckle and is stabilized by RNA. In turn, nuclear speckle morphology appears to depend on RCOR2. Specifically, RCOR2 knockdown results larger nuclear speckles, whereas overexpressing RCOR2 leads to smaller and rounder nuclear speckles. Conclusion Our study suggests that RCOR2 is a regulatory component of the nuclear speckle bodies, setting this co-repressor protein as a factor that controls nuclear speckles behavior.

scholarly journals Molecular and morphological analysis of the developing nemertean brain indicates convergent evolution of complex brains in Spiralia

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Ludwik Gąsiorowski ◽  
Aina Børve ◽  
Irina A. Cherneva ◽  
Andrea Orús-Alcalde ◽  
Andreas Hejnol
Keyword(s):  
Neural Development ◽  
Evolutionary Process ◽  
Cell Types ◽  
Major Elements ◽  
Brain Cell ◽  
Mushroom Bodies ◽  
Brain Anatomy ◽  
Last Common Ancestor ◽  
Specific Expression ◽  
The Brain

Abstract Background The brain anatomy in the clade Spiralia can vary from simple, commissural brains (e.g., gastrotrichs, rotifers) to rather complex, partitioned structures (e.g., in cephalopods and annelids). How often and in which lineages complex brains evolved still remains unclear. Nemerteans are a clade of worm-like spiralians, which possess a complex central nervous system (CNS) with a prominent brain, and elaborated chemosensory and neuroglandular cerebral organs, which have been previously suggested as homologs to the annelid mushroom bodies. To understand the developmental and evolutionary origins of the complex brain in nemerteans and spiralians in general, we investigated details of the neuroanatomy and gene expression in the brain and cerebral organs of the juveniles of nemertean Lineus ruber. Results In the juveniles, the CNS is already composed of all major elements present in the adults, including the brain, paired longitudinal lateral nerve cords, and an unpaired dorsal nerve cord, which suggests that further neural development is mostly related with increase in the size but not in complexity. The ultrastructure of the juvenile cerebral organ revealed that it is composed of several distinct cell types present also in the adults. The 12 transcription factors commonly used as brain cell type markers in bilaterians show region-specific expression in the nemertean brain and divide the entire organ into several molecularly distinct areas, partially overlapping with the morphological compartments. Additionally, several of the mushroom body-specific genes are expressed in the developing cerebral organs. Conclusions The dissimilar expression of molecular brain markers between L. ruber and the annelid Platynereis dumerilii indicates that the complex brains present in those two species evolved convergently by independent expansions of non-homologous regions of a simpler brain present in their last common ancestor. Although the same genes are expressed in mushroom bodies and cerebral organs, their spatial expression within organs shows apparent differences between annelids and nemerteans, indicating convergent recruitment of the same genes into patterning of non-homologous organs or hint toward a more complicated evolutionary process, in which conserved and novel cell types contribute to the non-homologous structures.

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 Revealing RCOR2 as a regulatory component of nuclear speckles

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Carlos Rivera ◽  
Daniel Verbel-Vergara ◽  
Duxan Arancibia ◽  
Anna Lappala ◽  
Marcela González ◽  
...  
Keyword(s):  
System Development ◽  
Cell Types ◽  
Nervous System Development ◽  
Nuclear Bodies ◽  
Nuclear Speckles ◽  
Nuclear Speckle ◽  
Multiple Cell ◽  
Rna Maturation ◽  
Nuclear Processes ◽  
The Brain

Abstract Background Nuclear processes such as transcription and RNA maturation can be impacted by subnuclear compartmentalization in condensates and nuclear bodies. Here, we characterize the nature of nuclear granules formed by REST corepressor 2 (RCOR2), a nuclear protein essential for pluripotency maintenance and central nervous system development. Results Using biochemical approaches and high-resolution microscopy, we reveal that RCOR2 is localized in nuclear speckles across multiple cell types, including neurons in the brain. RCOR2 forms complexes with nuclear speckle components such as SON, SRSF7, and SRRM2. When cells are exposed to chemical stress, RCOR2 behaves as a core component of the nuclear speckle and is stabilized by RNA. In turn, nuclear speckle morphology appears to depend on RCOR2. Specifically, RCOR2 knockdown results larger nuclear speckles, whereas overexpressing RCOR2 leads to smaller and rounder nuclear speckles. Conclusion Our study suggests that RCOR2 is a regulatory component of the nuclear speckle bodies, setting this co-repressor protein as a factor that controls nuclear speckles behavior.

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 Gene expression in the developing nemertean brain indicates convergent evolution of complex brains in Spiralia

2021 ◽  
Author(s):  
Ludwik Gąsiorowski ◽  
Aina Børve ◽  
Irina A. Cherneva ◽  
Andrea Orús-Alcalde ◽  
Andreas Hejnol
Keyword(s):  
Gene Expression ◽  
Neural Development ◽  
Cell Types ◽  
Major Elements ◽  
Mushroom Bodies ◽  
Animal Group ◽  
Evolutionary Origins ◽  
The Moment ◽  
Cerebral Organ ◽  
The Brain

AbstractBackgroundNemertea is a clade of worm-like animals, which belongs to a larger animal group called Spiralia (together with e.g. annelids, flatworms and mollusks). Many of the nemertean species possess a complex central nervous system (CNS) with a prominent brain, and elaborated chemosensory and neuroglandular cerebral organs, which have been suggested as homologues to the annelid mushroom bodies. In order to understand the developmental and evolutionary origins of complex nemertean brain, we investigated details of neuroanatomy and gene expression in the brain and cerebral organs of the juveniles of nemertean Lineus ruber.ResultsIn the hatched juveniles the CNS is already composed of all major elements present in the adults, including the brain (with dorsal and ventral lobes), paired longitudinal lateral nerve cords and an unpaired dorsal nerve cord. The TEM investigation of the juvenile cerebral organ revealed that the structure is already composed of several distinct cell types present also in the adults. We further investigated the expression of twelve transcription factors commonly used as brain and cell type markers in bilaterian brains, including genes specific for annelid mushroom bodies. The expression of the investigated genes in the brain is region-specific and divides the entire organ into several molecularly distinct areas, partially overlapping with the morphological compartments. Additionally, we detected expression of mushroom body specific genes in the developing cerebral organs.ConclusionsAt the moment of hatching, the juveniles of L. ruber already have a similar neuroarchitecture as adult worms, which suggests that further neural development is mostly related with increase in the size but not in complexity. Comparison in the gene expression between L. ruber and the annelid Platynereis dumerilii and other spiralians, indicates that the complex brains present in those two species evolved convergently by independent expansion of non-homologues regions of the simpler brain present in their common ancestor. The similarities in gene expression in mushroom bodies and cerebral organs might be a result of the convergent recruitment of the same genes into patterning of non-homologues organs or the results of more complicated evolutionary processes, in which conserved and novel cell types contribute to the non-homologues structures.

scholarly journals Imaging and Manipulating Pituitary Function in the Awake Mouse

Endocrinology ◽  
2019 ◽  
Vol 160 (10) ◽  
pp. 2271-2281 ◽  
Author(s):  
Ombeline Hoa ◽  
Chrystel Lafont ◽  
Pierre Fontanaud ◽  
Anne Guillou ◽  
Yasmine Kemkem ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Cell Types ◽  
Temporal Regulation ◽  
Hypothalamic Regulation ◽  
Health And Disease ◽  
Multiple Cell ◽  
Relationship Of ◽  
The Relationship ◽  
The Brain

Abstract Extensive efforts have been made to explore how the activities of multiple brain cells combine to alter physiology through imaging and cell-specific manipulation in different animal models. However, the temporal regulation of peripheral organs by the neuroendocrine factors released by the brain is poorly understood. We have established a suite of adaptable methodologies to interrogate in vivo the relationship of hypothalamic regulation with the secretory output of the pituitary gland, which has complex functional networks of multiple cell types intermingled with the vasculature. These allow imaging and optogenetic manipulation of cell activities in the pituitary gland in awake mouse models, in which both neuronal regulatory activity and hormonal output are preserved. These methodologies are now readily applicable for longitudinal studies of short-lived events (e.g., calcium signals controlling hormone exocytosis) and slowly evolving processes such as tissue remodeling in health and disease over a period of days to weeks.

scholarly journals In Search of Molecular Markers for Cerebellar Neurons

2021 ◽  
Vol 22 (4) ◽  
pp. 1850
Author(s):  
Wing Yip Tam ◽  
Xia Wang ◽  
Andy S. K. Cheng ◽  
Kwok-Kuen Cheung
Keyword(s):  
Cognitive Deficits ◽  
Motor Coordination ◽  
Normal Development ◽  
Genetic Manipulation ◽  
Cell Types ◽  
Functional Study ◽  
Cerebellar Neurons ◽  
The Brain ◽  
Neuronal Type

The cerebellum, the region of the brain primarily responsible for motor coordination and balance, also contributes to non-motor functions, such as cognition, speech, and language comprehension. Maldevelopment and dysfunction of the cerebellum lead to cerebellar ataxia and may even be associated with autism, depression, and cognitive deficits. Hence, normal development of the cerebellum and its neuronal circuitry is critical for the cerebellum to function properly. Although nine major types of cerebellar neurons have been identified in the cerebellar cortex to date, the exact functions of each type are not fully understood due to a lack of cell-specific markers in neurons that renders cell-specific labeling and functional study by genetic manipulation unfeasible. The availability of cell-specific markers is thus vital for understanding the role of each neuronal type in the cerebellum and for elucidating the interactions between cell types within both the developing and mature cerebellum. This review discusses various technical approaches and recent progress in the search for cell-specific markers for cerebellar neurons.

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