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1.
Proc Natl Acad Sci U S A ; 120(1): e2210967120, 2023 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-36574666

RESUMO

The convolutions of the mammalian cerebral cortex allow the enlargement of its surface and addition of novel functional areas during evolution while minimizing expansion of the cranium. Cognitive neurodevelopmental disorders in humans, including microcephaly and lissencephaly, are often associated with impaired gyrification. In the classical model of gyrification, surface area is initially set by the number of radial units, and the forces driving cortical folding include neuronal growth, formation of neuropil, glial cell intercalation, and the patterned growth of subcortical white matter. An alternative model proposes that specified neurogenic hotspots in the outer subventricular zone (oSVZ) produce larger numbers of neurons that generate convexities in the cortex. This directly contradicts reports showing that cortical neurogenesis and settling of neurons into the cortical plate in primates, including humans, are completed well prior to the formation of secondary and tertiary gyri and indeed most primary gyri. In addition, during the main period of gyrification, the oSVZ produces mainly astrocytes and oligodendrocytes. Here we describe how rapid growth of intracortical neuropil, addition of glial cells, and enlargement of subcortical white matter in primates are the primary forces responsible for the post-neurogenic expansion of the cortical surface and formation of gyri during fetal development. Using immunohistochemistry for markers of proliferation and glial and neuronal progenitors combined with transcriptomic analysis, we show that neurogenesis in the ventricular zone and oSVZ is phased out and transitions to gliogenesis prior to gyral development. In summary, our data support the classical model of gyrification and provide insight into the pathogenesis of congenital cortical malformations.


Assuntos
Córtex Cerebral , Primatas , Humanos , Animais , Córtex Cerebral/metabolismo , Neurônios , Neuroglia , Neurópilo , Mamíferos
2.
Neural Netw ; 156: 218-238, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36279780

RESUMO

The neuropil, the plexus of axons and dendrites, plays a critical role in operating the circuit processing of the nervous system. Revealing the spatiotemporal activity pattern within the neuropil would clarify how the information flows throughout the nervous system. However, calcium imaging to examine the circuit dynamics has mainly focused on the soma population due to their discrete distribution. The development of a methodology to analyze the calcium imaging data of a densely packed neuropil would provide us with new insights into the circuit dynamics. Here, we propose a new method to decompose calcium imaging data of the neuropil into populations of bouton-like synaptic structures with a standard desktop computer. To extract bouton-like structures from calcium imaging data, we introduced a new type of modularity, a widely used quality measure in graph theory, and optimized the clustering configuration by a simulated annealing algorithm, which is established in statistical physics. To assess this method's performance, we conducted calcium imaging of the neuropil of Drosophila larvae. Based on the obtained data, we established artificial neuropil imaging datasets. We applied the decomposition procedure to the artificial and experimental calcium imaging data and extracted individual bouton-like structures successfully. Based on the extracted spatiotemporal data, we analyzed the network structure of the central nervous system of fly larvae and found it was scale-free. These results demonstrate that neuropil calcium imaging and its decomposition could provide new insight into our understanding of neural processing.


Assuntos
Cálcio , Neurópilo , Neurópilo/fisiologia , Neurônios , Axônios
3.
Acta Med Okayama ; 76(4): 473-477, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36123163

RESUMO

Glioneuronal tumor with neuropil-like islands (GNTNI) is a very rare subtype of glioneuronal tumor. We present a case of a 62-year-old man with GNTNI. Two adjacent lesions in the left parietal lobe were removed by left parietal craniotomy. The histological findings were glial cell proliferation and scattered rosettes consisting of synaptophysin-positive and NeuN-positive cells, leading to the diagnosis of GNTNI. Target sequencing revealed a genetic alteration similar to glioblastoma, IDH-wild type, which suggested adjuvant therapies. There are few previous reports on the treatment of this disease, and the patient should be followed carefully.


Assuntos
Neoplasias Encefálicas , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Genômica , Humanos , Ilhas , Masculino , Pessoa de Meia-Idade , Neurópilo/metabolismo , Neurópilo/patologia , Sinaptofisina
4.
Proc Biol Sci ; 289(1981): 20220812, 2022 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-35975436

RESUMO

When an animal rotates (whether it is an arthropod, a fish, a bird or a human) a drift of the visual panorama occurs over its retina, termed optic flow. The image is stabilized by compensatory behaviours (driven by the movement of the eyes, head or the whole body depending on the animal) collectively termed optomotor responses. The dipteran lobula plate has been consistently linked with optic flow processing and the control of optomotor responses. Crabs have a neuropil similarly located and interconnected in the optic lobes, therefore referred to as a lobula plate too. Here we show that the crabs' lobula plate is required for normal optomotor responses since the response was lost or severely impaired in animals whose lobula plate had been lesioned. The effect was behaviour-specific, since avoidance responses to approaching visual stimuli were not affected. Crabs require simpler optic flow processing than flies (because they move slower and in two-dimensional instead of three-dimensional space), consequently their lobula plates are relatively smaller. Nonetheless, they perform the same essential role in the visual control of behaviour. Our findings add a fundamental piece to the current debate on the evolutionary relationship between the lobula plates of insects and crustaceans.


Assuntos
Braquiúros , Dípteros , Fluxo Óptico , Animais , Braquiúros/fisiologia , Humanos , Neurópilo/fisiologia , Lobo Óptico de Animais não Mamíferos , Vias Visuais/fisiologia
5.
Nature ; 607(7920): 747-755, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35794476

RESUMO

When deciding what to eat, animals evaluate sensory information about food quality alongside multiple ongoing internal states1-10. How internal states interact to alter sensorimotor processing and shape decisions such as food choice remains poorly understood. Here we use pan-neuronal volumetric activity imaging in the brain of Drosophila melanogaster to investigate the neuronal basis of internal state-dependent nutrient appetites. We created a functional atlas of the ventral fly brain and find that metabolic state shapes sensorimotor processing across large sections of the neuropil. By contrast, reproductive state acts locally to define how sensory information is translated into feeding motor output. These two states thus synergistically modulate protein-specific food intake and food choice. Finally, using a novel computational strategy, we identify driver lines that label neurons innervating state-modulated brain regions and show that the newly identified 'borboleta' region is sufficient to direct food choice towards protein-rich food. We thus identify a generalizable principle by which distinct internal states are integrated to shape decision making and propose a strategy to uncover and functionally validate how internal states shape behaviour.


Assuntos
Drosophila melanogaster , Preferências Alimentares , Lógica , Neurônios , Animais , Apetite/fisiologia , Proteínas na Dieta , Drosophila melanogaster/fisiologia , Retroalimentação Sensorial , Preferências Alimentares/fisiologia , Neurônios/fisiologia , Neurópilo/fisiologia
6.
Nat Neurosci ; 25(6): 726-737, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35654957

RESUMO

Learning induces the formation of new excitatory synapses in the form of dendritic spines, but their functional properties remain unknown. Here, using longitudinal in vivo two-photon imaging and correlated electron microscopy of dendritic spines in the motor cortex of mice during motor learning, we describe a framework for the formation, survival and resulting function of new, learning-related spines. Specifically, our data indicate that the formation of new spines during learning is guided by the potentiation of functionally clustered preexisting spines exhibiting task-related activity during earlier sessions of learning. We present evidence that this clustered potentiation induces the local outgrowth of multiple filopodia from the nearby dendrite, locally sampling the adjacent neuropil for potential axonal partners, likely via targeting preexisting presynaptic boutons. Successful connections are then selected for survival based on co-activity with nearby task-related spines, ensuring that the new spine preserves functional clustering. The resulting locally coherent activity of new spines signals the learned movement. Furthermore, we found that a majority of new spines synapse with axons previously unrepresented in these dendritic domains. Thus, learning involves the binding of new information streams into functional synaptic clusters to subserve learned behaviors.


Assuntos
Aprendizagem , Sinapses , Animais , Axônios , Espinhas Dendríticas , Camundongos , Neurópilo , Terminações Pré-Sinápticas , Sinapses/metabolismo
7.
J Comp Neurol ; 530(14): 2416-2438, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35593178

RESUMO

The central complex (CX) in the brain of insects is a highly conserved group of midline-spanning neuropils consisting of the upper and lower division of the central body, the protocerebral bridge, and the paired noduli. These neuropils are the substrate for a number of behaviors, most prominently goal-oriented locomotion. Honeybees have been a model organism for sky-compass orientation for more than 70 years, but there is still very limited knowledge about the structure and function of their CX. To advance and facilitate research on this brain area, we created a high-resolution three-dimensional atlas of the honeybee's CX and associated neuropils, including the posterior optic tubercles, the bulbs, and the anterior optic tubercles. To this end, we developed a modified version of the iterative shape averaging technique, which allowed us to achieve high volumetric accuracy of the neuropil models. For a finer definition of spatial locations within the central body, we defined layers based on immunostaining against the neuropeptides locustatachykinin, FMRFamide, gastrin/cholecystokinin, and allatostatin and included them into the atlas by elastic registration. Our honeybee CX atlas provides a platform for future neuroanatomical work.


Assuntos
Neurônios , Neurópilo , Animais , Abelhas , Encéfalo , Insetos , Neuroanatomia
8.
Sci Rep ; 12(1): 8256, 2022 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-35585164

RESUMO

Many insects show plasticity in the area of the brain called the mushroom bodies (MB) with foraging and social experience. MBs are paired neuropils associated with learning and memory. MB volume is typically greater in mature foragers relative to young and/or inexperienced individuals. Long-term studies show that extended experience may further increase MB volume, but long-term studies have only been performed on non-reproductive social insect workers. Here we use the subsocial bee Ceratina calcarata to test the effect of extended foraging experience on MB volume among reproductive females. Ceratina calcarata females forage to provision their immature offspring in the spring, and then again to provision their adult daughters in the late summer. We measured the volume of the MB calyces and peduncle, antennal lobes (AL), optic lobes (OL), central complex (CX), and whole brains of three groups of bees: newly emerged females, reproductive females in spring (foundresses), and post-reproductive mothers feeding their adult daughters in late summer. Post-reproductive late summer mothers had smaller MB calyces and ALs than foundresses. Moreover, among late mothers (but not other bees), wing wear, which is a measure of foraging experience, negatively correlated with both MB and OL volume. This is contrary to previously studied non-reproductive social insect workers in which foraging experience correlates postiviely with MB volume, and suggests that post-reproductive bees may reduce neural investment near the end of their lives.


Assuntos
Corpos Pedunculados , Neurópilo , Animais , Abelhas , Encéfalo , Feminino , Aprendizagem , Reprodução
9.
Medicine (Baltimore) ; 101(19): e29237, 2022 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-35583532

RESUMO

RATIONALE: Glioneuronal tumor with neuropil-like islands (GTNI) is a distinctive neoplasm located in the cerebrum. Moreover, spinal GTNI is extremely rare. Herein, we present a case of spinal GTNI and review the related literature. PATIENT CONCERNS: A 38-year-old Chinese woman presented to our hospital with a 6-month history of neck pain and a 1-month history of dizziness. DIAGNOSES: Magnetic resonance imaging revealed a large intramedullary mass spanning the length of the spinal cord from C1 to C4. Microscopic and immunohistochemical examinations of the tumor tissue revealed findings typical of GTNI. INTERVENTIONS: The patient underwent C1 to C4 intraspinal gross tumor resection. OUTCOMES: Follow-up results showed that the patient had no recurrence 6 months after tumor resection. LESSONS: GTNI in the spinal cord is a highly rare neoplasm with poor prognosis. Therefore, clinicians and pathologists should differentiate GTNI from other benign glioneuronal tumors, and long-term follow-up of patients with spinal GTNI is necessary.


Assuntos
Neoplasias Encefálicas , Neoplasias da Medula Espinal , Neoplasias da Coluna Vertebral , Adulto , Neoplasias Encefálicas/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Neurópilo/patologia , Neoplasias da Medula Espinal/diagnóstico por imagem , Neoplasias da Medula Espinal/cirurgia , Neoplasias da Coluna Vertebral/patologia
10.
Cold Spring Harb Protoc ; 2022(8): pdb.prot107840, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35562110

RESUMO

The Golgi silver staining procedure relies on three interdependent stages: fixation, chromation, and metal impregnation. Each of these stages can be modified. This protocol describes a method demonstrated to stain neurons within the mosquito central nervous system. The resulting preparations are stable at room temperature.


Assuntos
Culicidae , Animais , Técnicas Histológicas , Neurônios , Neurópilo , Coloração pela Prata/métodos , Coloração e Rotulagem
11.
eNeuro ; 9(2)2022.
Artigo em Inglês | MEDLINE | ID: mdl-35410869

RESUMO

Electron microscopy (EM)-based connectomes provide important insights into how visual circuitry of fruit fly Drosophila computes various visual features, guiding and complementing behavioral and physiological studies. However, connectomic analyses of the lobula, a neuropil putatively dedicated to detecting object-like features, remains underdeveloped, largely because of incomplete data on the inputs to the brain region. Here, we attempted to map the columnar inputs into the Drosophila lobula neuropil by performing connectivity-based and morphology-based clustering on a densely reconstructed connectome dataset. While the dataset mostly lacked visual neuropils other than lobula, which would normally help identify inputs to lobula, our clustering analysis successfully extracted clusters of cells with homogeneous connectivity and morphology, likely representing genuine cell types. We were able to draw a correspondence between the resulting clusters and previously identified cell types, revealing previously undocumented connectivity between lobula input and output neurons. While future, more complete connectomic reconstructions are necessary to verify the results presented here, they can serve as a useful basis for formulating hypotheses on mechanisms of visual feature detection in lobula.


Assuntos
Conectoma , Drosophila , Animais , Drosophila/fisiologia , Drosophila melanogaster/fisiologia , Neurônios/fisiologia , Neurópilo , Vias Visuais/fisiologia
12.
J Neural Eng ; 19(2)2022 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-35263736

RESUMO

Objective. Neural prosthetics often use intracortical microstimulation (ICMS) for sensory restoration. To restore natural and functional feedback, we must first understand how stimulation parameters influence the recruitment of neural populations. ICMS waveform asymmetry modulates the spatial activation of neurons around an electrode at 10 Hz; however, it is unclear how asymmetry may differentially modulate population activity at frequencies typically employed in the clinic (e.g. 100 Hz). We hypothesized that stimulation waveform asymmetry would differentially modulate preferential activation of certain neural populations, and the differential population activity would be frequency-dependent.Approach. We quantified how asymmetric stimulation waveforms delivered at 10 or 100 Hz for 30 s modulated spatiotemporal activity of cortical layer II/III pyramidal neurons usingin vivotwo-photon and mesoscale calcium imaging in anesthetized mice. Asymmetry is defined in terms of the ratio of the duration of the leading phase to the duration of the return phase of charge-balanced cathodal- and anodal-first waveforms (i.e. longer leading phase relative to return has larger asymmetry).Main results. Neurons within 40-60µm of the electrode display stable stimulation-induced activity indicative of direct activation, which was independent of waveform asymmetry. The stability of 72% of activated neurons and the preferential activation of 20%-90% of neurons depended on waveform asymmetry. Additionally, this asymmetry-dependent activation of different neural populations was associated with differential progression of population activity. Specifically, neural activity tended to increase over time during 10 Hz stimulation for some waveforms, whereas activity remained at the same level throughout stimulation for other waveforms. During 100 Hz stimulation, neural activity decreased over time for all waveforms, but decreased more for the waveforms that resulted in increasing neural activity during 10 Hz stimulation.Significance.These data demonstrate that at frequencies commonly used for sensory restoration, stimulation waveform alters the pattern of activation of different but overlapping populations of excitatory neurons. The impact of these waveform specific responses on the activation of different subtypes of neurons as well as sensory perception merits further investigation.


Assuntos
Neurônios , Neurópilo , Animais , Estimulação Elétrica/métodos , Camundongos , Microeletrodos , Neurônios/fisiologia , Células Piramidais/fisiologia
13.
J Comp Neurol ; 530(10): 1533-1550, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34985823

RESUMO

The visual neuropils (lamina, medulla, and lobula complex) of malacostracan crustaceans and hexapods have many organizational principles, cell types, and functional properties in common. Information about the cellular elements that compose the crustacean lobula is scarce especially when focusing on small columnar cells. Semiterrestrial crabs possess a highly developed visual system and display conspicuous visually guided behaviors. In particular, Neohelice granulata has been previously used to describe the cellular components of the first two optic neuropils using Golgi impregnation technique. Here, we present a comprehensive description of individual elements composing the third optic neuropil, the lobula, of that same species. We characterized a wide variety of elements (140 types) including input terminals and lobula columnar, centrifugal, and input columnar elements. Results reveal a very dense and complex neuropil. We found a frequently impregnated input element (suggesting a supernumerary cartridge representation) that arborizes in the third layer of the lobula and that presents four variants each with ramifications organized following one of the four cardinal axes suggesting a role in directional processing. We also describe input elements with two neurites branching in the third layer, probably connecting with the medulla and lobula plate. These facts suggest that this layer is involved in the directional motion detection pathway in crabs. We analyze and discuss our findings considering the similarities and differences found between the layered organization and components of this crustacean lobula and the lobula of insects.


Assuntos
Braquiúros , Animais , Bulbo , Neurônios/fisiologia , Neurópilo/fisiologia , Lobo Óptico de Animais não Mamíferos/fisiologia , Vias Visuais/fisiologia
14.
Cereb Cortex ; 32(17): 3669-3689, 2022 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-35059716

RESUMO

Fast synaptic communication uses diffusible transmitters whose spread is limited by uptake mechanisms. However, on the submicron-scale, the distance between two synapses, the extent of glutamate spread has so far remained difficult to measure. Here, we show that quantal glutamate release from individual hippocampal synapses activates extracellular iGluSnFr molecules at a distance of >1.5 µm. 2P-glutamate uncaging near spines further showed that alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-Rs and N-methyl-D-aspartate (NMDA)-Rs respond to distant uncaging spots at approximately 800 and 2000 nm, respectively, when releasing the amount of glutamate contained in approximately five synaptic vesicles. The uncaging-induced remote activation of AMPA-Rs was facilitated by blocking glutamate transporters but only modestly decreased by elevating the recording temperature. When mimicking release from neighboring synapses by three simultaneous uncaging spots in the microenvironment of a spine, AMPA-R-mediated responses increased supra-additively. Interfering with extracellular glutamate diffusion through a glutamate scavenger system weakly reduced field synaptic responses but not the quantal amplitude. Together, our data suggest that the neuropil is more permissive to short-range spread of transmitter than suggested by theory, that multivesicular release could regularly coactivate nearest neighbor synapses and that on this scale glutamate buffering by transporters primarily limits the spread of transmitter and allows for cooperative glutamate signaling in extracellular microdomains.


Assuntos
Ácido Glutâmico , Receptores de AMPA , Ácido Glutâmico/farmacologia , Hipocampo/fisiologia , Neurópilo/metabolismo , Receptores de AMPA/fisiologia , Receptores de N-Metil-D-Aspartato/metabolismo , Sinapses/fisiologia , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico/farmacologia
15.
J Comp Neurol ; 530(6): 886-902, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34608995

RESUMO

In the highly dynamic metabolic landscape of a neuron, mitochondrial membrane architectures can provide critical insight into the unique energy balance of the cell. Current theoretical calculations of functional outputs like adenosine triphosphate and heat often represent mitochondria as idealized geometries, and therefore, can miscalculate the metabolic fluxes. To analyze mitochondrial morphology in neurons of mouse cerebellum neuropil, 3D tracings of complete synaptic and axonal mitochondria were constructed using a database of serial transmission electron microscopy (TEM) tomography images and converted to watertight meshes with minimal distortion of the original microscopy volumes with a granularity of 1.64 nanometer isotropic voxels. The resulting in-silico representations were subsequently quantified by differential geometry methods in terms of the mean and Gaussian curvatures, surface areas, volumes, and membrane motifs, all of which can alter the metabolic output of the organelle. Finally, we identify structural motifs present across this population of mitochondria, which may contribute to future modeling studies of mitochondrial physiology and metabolism in neurons.


Assuntos
Cerebelo , Mitocôndrias , Neurônios , Neurópilo , Animais , Camundongos
16.
J Comp Neurol ; 530(9): 1399-1422, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34843626

RESUMO

The primary olfactory centers of metazoans as diverse as arthropods and mammals consist of an array of fields of dense synaptic neuropil, the olfactory glomeruli. However, the neurochemical structure of crustacean olfactory glomeruli is largely understudied when compared to the insects. We analyzed the glomerular architecture in selected species of hermit crabs using immunohistochemistry against presynaptic proteins, the neuropeptides orcokinin, RFamide and allatostatin, and the biogenic amine serotonin. Our study reveals an unexpected level of structural complexity, unmatched by what is found in the insect olfactory glomeruli. Peptidergic and aminergic interneurons provide the structural basis for a regionalization of the crustacean glomeruli into longitudinal and concentric compartments. Our data suggest that local olfactory interneurons take a central computational role in modulating the information transfer from olfactory sensory neurons to projection neurons within the glomeruli. Furthermore, we found yet unknown neuronal elements mediating lateral inhibitory interactions across the glomerular array that may play a central role in modulating the transfer of sensory input to the output neurons through presynaptic inhibition. Our study is another step in understanding the function of crustacean olfactory glomeruli as highly complex units of local olfactory processing.


Assuntos
Anomuros , Neurônios Receptores Olfatórios , Animais , Interneurônios , Mamíferos , Neurópilo/metabolismo , Bulbo Olfatório , Condutos Olfatórios/metabolismo
17.
Nat Commun ; 12(1): 6357, 2021 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-34737284

RESUMO

In the central nervous system (CNS), functional tasks are often allocated to distinct compartments. This is also evident in the Drosophila CNS where synapses and dendrites are clustered in distinct neuropil regions. The neuropil is separated from neuronal cell bodies by ensheathing glia, which as we show using dye injection experiments, contribute to the formation of an internal diffusion barrier. We find that ensheathing glia are polarized with a basolateral plasma membrane rich in phosphatidylinositol-(3,4,5)-triphosphate (PIP3) and the Na+/K+-ATPase Nervana2 (Nrv2) that abuts an extracellular matrix formed at neuropil-cortex interface. The apical plasma membrane is facing the neuropil and is rich in phosphatidylinositol-(4,5)-bisphosphate (PIP2) that is supported by a sub-membranous ßHeavy-Spectrin cytoskeleton. ßHeavy-spectrin mutant larvae affect ensheathing glial cell polarity with delocalized PIP2 and Nrv2 and exhibit an abnormal locomotion which is similarly shown by ensheathing glia ablated larvae. Thus, polarized glia compartmentalizes the brain and is essential for proper nervous system function.


Assuntos
Encéfalo/metabolismo , Proteínas de Drosophila/metabolismo , Neuroglia/metabolismo , Neurônios/metabolismo , Neurópilo/metabolismo , Espectrina/metabolismo , Animais , Linhagem da Célula , Drosophila , Glicoproteínas/metabolismo , Larva , Proteínas do Tecido Nervoso/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo
18.
Nat Commun ; 12(1): 6127, 2021 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-34675203

RESUMO

Owing to their morphological complexity and dense network connections, neurons modify their proteomes locally, using mRNAs and ribosomes present in the neuropil (tissue enriched for dendrites and axons). Although ribosome biogenesis largely takes place in the nucleus and perinuclear region, neuronal ribosomal protein (RP) mRNAs have been frequently detected remotely, in dendrites and axons. Here, using imaging and ribosome profiling, we directly detected the RP mRNAs and their translation in the neuropil. Combining brief metabolic labeling with mass spectrometry, we found that a group of RPs rapidly associated with translating ribosomes in the cytoplasm and that this incorporation was independent of canonical ribosome biogenesis. Moreover, the incorporation probability of some RPs was regulated by location (neurites vs. cell bodies) and changes in the cellular environment (following oxidative stress). Our results suggest new mechanisms for the local activation, repair and/or specialization of the translational machinery within neuronal processes, potentially allowing neuronal synapses a rapid means to regulate local protein synthesis.


Assuntos
Neurônios/metabolismo , Proteínas Ribossômicas/metabolismo , Ribossomos/metabolismo , Animais , Axônios/metabolismo , Células Cultivadas , Feminino , Masculino , Neuritos/metabolismo , Neurópilo/metabolismo , Biossíntese de Proteínas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Proteínas Ribossômicas/genética , Ribossomos/genética
19.
J Comp Neurol ; 529(15): 3533-3560, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34216020

RESUMO

The lateral complexes (LXs) are bilaterally paired neuropils in the insect brain that mediate communication between the central complex (CX), a brain center controlling spatial orientation, various sensory processing areas, and thoracic motor centers that execute locomotion. The LX of the desert locust consists of the lateral accessory lobe (LAL), and the medial and lateral bulb. We have analyzed the anatomical organization and the neuronal connections of the LX in the locust, to provide a basis for future functional studies. Reanalyzing the morphology of neurons connecting the CX and the LX revealed likely feedback loops in the sky compass network of the CX via connections in the gall of the LAL and a newly identified neuropil termed ovoid body. In addition, we characterized 16 different types of neuron that connect the LAL with other areas in the brain. Eight types of neuron provide information flow between both LALs, five types are LAL input neurons, and three types are LAL output neurons. Among these are neurons providing input from sensory brain areas such as the lobula and antennal neuropils. Brain regions most often targeted by LAL neurons are the posterior slope, the wedge, and the crepine. Two descending neurons with dendrites in the LAL were identified. Our data support and complement existing knowledge about how the LAL is embedded in the neuronal network involved in processing of sensory information and generation of appropriate behavioral output for goal-directed locomotion.


Assuntos
Encéfalo/citologia , Encéfalo/diagnóstico por imagem , Imageamento Tridimensional/métodos , Rede Nervosa/citologia , Rede Nervosa/diagnóstico por imagem , Animais , Encéfalo/fisiologia , Química Encefálica , Feminino , Gafanhotos , Masculino , Rede Nervosa/química , Neurópilo/química , Neurópilo/citologia
20.
Elife ; 102021 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-33988500

RESUMO

The pheromone system of heliothine moths is an optimal model for studying principles underlying higher-order olfactory processing. In Helicoverpa armigera, three male-specific glomeruli receive input about three female-produced signals, the primary pheromone component, serving as an attractant, and two minor constituents, serving a dual function, that is, attraction versus inhibition of attraction. From the antennal-lobe glomeruli, the information is conveyed to higher olfactory centers, including the lateral protocerebrum, via three main paths - of which the medial tract is the most prominent. In this study, we traced physiologically identified medial-tract projection neurons from each of the three male-specific glomeruli with the aim of mapping their terminal branches in the lateral protocerebrum. Our data suggest that the neurons' widespread projections are organized according to behavioral significance, including a spatial separation of signals representing attraction versus inhibition - however, with a unique capacity of switching behavioral consequence based on the amount of the minor components.


Assuntos
Mariposas/fisiologia , Condutos Olfatórios/fisiologia , Animais , Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Masculino , Mariposas/anatomia & histologia , Neurópilo/fisiologia , Odorantes , Condutos Olfatórios/anatomia & histologia , Feromônios/química , Feromônios/farmacologia
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