Neuronal organization of the brain in the adult amphioxus (Branchiostoma lanceolatum): A study with acetylated tubulin immunohistochemistry

Microtubule (MT) dynamics are modulated through the coordinated action of various MT-associated proteins (MAPs). However, the regulatory mechanisms underlying MT dynamics remain unclear. Herein, we show that MAP7 family protein Map7D2 facilitates MT stabilization to control cell motility and neurite outgrowth. Map7D2, was highly expressed in the brain and testis, directly bound to MTs through its N-terminal half similarly to Map7, and promoted MT stabilization in vitro. Map7D2 localized prominently to the centrosome and partially on MTs in N1-E115 mouse glioblastoma cells, which expresses two of the four MAP7 family members, Map7D2 and Map7D1. Map7D2 loss decreased the intensity of MTs without affecting stable MT markers acetylated and detyrosinated tubulin, suggesting that Map7D2 stabilizes MTs via direct binding. In addition, Map7D2 loss increased the rate of random cell migration and neurite outgrowth, presumably by disturbing the balance between MT stabilization and destabilization. The other MAP7 family protein expressed in N1-E115, Map7D1, exhibited similar subcellular localization and gene knock-down phenotypes. However, in contrast to Map7D2, Map7D1 was required for the maintenance of acetylated tubulin levels. Taken together, our data suggest that Map7D2 and Map7D1 facilitate MT stabilization through distinct mechanisms for the control of cell motility and neurite outgrowth.

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The neuronal basis for consciousness

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.1998.0336 ◽

1998 ◽

Vol 353 (1377) ◽

pp. 1841-1849 ◽

Cited By ~ 394

Author(s):

◽

R. Llinás ◽

U. Ribary ◽

D. Contreras ◽

C. Pedroarena

Keyword(s):

Large Scale ◽

Basic Assumption ◽

Human Cognition ◽

Neuronal Organization ◽

Global Function ◽

Loop Function ◽

Functional States ◽

The Rich ◽

First Time ◽

The Brain

Attempting to understand how the brain, as a whole, might be organized seems, for the first time, to be a serious topic of inquiry. One aspect of its neuronal organization that seems particularly central to global function is the rich thalamocortical interconnectivity, and most particularly the reciprocal nature of the thalamocortical neuronal loop function. Moreover, the interaction between the specific and non-specific thalamic loops suggests that rather than a gate into the brain, the thalamus represents a hub from which any site in the cortex can communicate with any other such site or sites. The goal of this paper is to explore the basic assumption that large–scale, temporal coincidence of specific and non–specific thalamic activity generates the functional states that characterize human cognition.

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The brain of Cataglyphis ants: Neuronal organization and visual projections

The Journal of Comparative Neurology ◽

10.1002/cne.24934 ◽

2020 ◽

Vol 528 (18) ◽

pp. 3479-3506 ◽

Cited By ~ 3

Author(s):

Jens Habenstein ◽

Emad Amini ◽

Kornelia Grübel ◽

Basil el Jundi ◽

Wolfgang Rössler

Keyword(s):

Neuronal Organization ◽

The Brain

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An atlas of the developing Tribolium castaneum brain reveals conserved anatomy and divergent timing to Drosophila melanogaster

10.1101/2021.11.30.470557 ◽

2021 ◽

Author(s):

Max S. Farnworth ◽

Gregor Bucher ◽

Volker Hartenstein

Keyword(s):

Tribolium Castaneum ◽

Genetic Basis ◽

Larval Instar ◽

Adult Brain ◽

Model Organisms ◽

Prepupal Stage ◽

Fibre Bundles ◽

Acetylated Tubulin ◽

High Degree ◽

The Brain

Insect brains are formed by conserved sets of neural lineages whose fibres form cohesive bundles with characteristic projection patterns. Within the brain neuropil these bundles establish a system of fascicles constituting the macrocircuitry of the brain. The overall architecture of the neuropils and the macrocircuitry appear to be conserved. However, variation is observed e.g., in size and shape and timing of development. Unfortunately, the developmental and genetic basis of this variation is poorly understood although the rise of new genetically tractable model organisms such as the red flour beetle Tribolium castaneum allows the possibility to gain mechanistic insights. To facilitate such work, we present an atlas of the developing brain of T. castaneum, covering the first larval instar, the prepupal stage and the adult, by combining wholemount immunohistochemical labelling of fibre bundles (acetylated tubulin) and neuropils (synapsin) with digital 3D reconstruction using the TrakEM2 software package. Upon comparing this anatomical dataset with the published work in D. melanogaster, we confirm an overall high degree of conservation. Fibre tracts and neuropil fascicles, which can be visualized by global neuronal antibodies like anti-acetylated tubulin in all invertebrate brains, create a rich anatomical framework to which individual neurons or other regions of interest can be referred to. The framework of a largely conserved pattern allowed us to describe differences between the two species with respect to parameters such as timing of neuron proliferation and maturation. These features likely reflect adaptive changes in developmental timing that govern the change from larval to adult brain.

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