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Srivastava Y, Donta M, Mireles LL, Paulucci-Holthauzen A, Shi L, Bedford MT, Waxham MN, McCrea PD. Exploring the PDZ, DUF, and LIM Domains of Pdlim5 in Dendrite Branching. Int J Mol Sci 2024; 25:8326. [PMID: 39125895 PMCID: PMC11312917 DOI: 10.3390/ijms25158326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2024] [Revised: 07/10/2024] [Accepted: 07/25/2024] [Indexed: 08/12/2024] Open
Abstract
The branched architecture of neuronal dendrites is a key factor in how neurons form ordered networks and discoveries continue to be made identifying proteins and protein-protein interactions that direct or execute the branching and extension of dendrites. Our prior work showed that the molecular scaffold Pdlim5 and delta-catenin, in conjunction, are two proteins that help regulate the branching and elongation of dendrites in cultured hippocampal neurons and do so through a phosphorylation-dependent mechanism triggered by upstream glutamate signaling. In this report we have focused on Pdlim5's multiple scaffolding domains and how each contributes to dendrite branching. The three identified regions within Pdlim5 are the PDZ, DUF, and a trio of LIM domains; however, unresolved is the intra-molecular conformation of Pdlim5 as well as which domains are essential to regulate dendritic branching. We address Pdlim5's structure and function by examining the role of each of the domains individually and using deletion mutants in the context of the full-length protein. Results using primary hippocampal neurons reveal that the Pdlim5 DUF domain plays a dominant role in increasing dendritic branching. Neither the PDZ domain nor the LIM domains alone support increased branching. The central role of the DUF domain was confirmed using deletion mutants in the context of full-length Pdlim5. Guided by molecular modeling, additional domain mapping studies showed that the C-terminal LIM domain forms a stable interaction with the N-terminal PDZ domain, and we identified key amino acid residues at the interface of each domain that are needed for this interaction. We posit that the central DUF domain of Pdlim5 may be subject to modulation in the context of the full-length protein by the intra-molecular interaction between the N-terminal PDZ and C-terminal LIM domains. Overall, our studies reveal a novel mechanism for the regulation of Pdlim5's function in the regulation of neuronal branching and highlight the critical role of the DUF domain in mediating these effects.
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Affiliation(s)
- Yogesh Srivastava
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Maxsam Donta
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Program in Genetics & Epigenetics, University of Texas MD Anderson Cancer Center, UT Health GSBS, Houston, TX 77030, USA
| | - Lydia L. Mireles
- Department of Neurobiology & Anatomy, University of Texas MD Anderson Cancer Center, UT Health GSBS, Houston, TX 77030, USA
| | | | - Leilei Shi
- Department of Epigenetics & Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Mark T. Bedford
- Program in Genetics & Epigenetics, University of Texas MD Anderson Cancer Center, UT Health GSBS, Houston, TX 77030, USA
- Department of Epigenetics & Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - M. Neal Waxham
- Department of Neurobiology & Anatomy, University of Texas MD Anderson Cancer Center, UT Health GSBS, Houston, TX 77030, USA
- Program in Neuroscience, University of Texas MD Anderson Cancer Center, UT Health GSBS, Houston, TX 77030, USA
| | - Pierre D. McCrea
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Program in Genetics & Epigenetics, University of Texas MD Anderson Cancer Center, UT Health GSBS, Houston, TX 77030, USA
- Program in Neuroscience, University of Texas MD Anderson Cancer Center, UT Health GSBS, Houston, TX 77030, USA
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2
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Wang W, Rui M. Advances in understanding the roles of actin scaffolding and membrane trafficking in dendrite development. J Genet Genomics 2024:S1673-8527(24)00152-8. [PMID: 38925347 DOI: 10.1016/j.jgg.2024.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 06/18/2024] [Accepted: 06/19/2024] [Indexed: 06/28/2024]
Abstract
Dendritic morphology is typically highly branched, and the branching and synaptic abundance of dendrites can enhance the receptive range of neurons and the diversity of information received, thus providing the basis for information processing in the nervous system. Once dendritic development is aberrantly compromised or damaged, it may lead to abnormal connectivity of the neural network, affecting the function and stability of the nervous system and ultimately triggering a series of neurological disorders. Research on the regulation of dendritic developmental processes has flourished, and much progress is now being made in its regulatory mechanisms. Noteworthily, dendrites are characterized by an extremely complex dendritic arborization that cannot be attributed to individual protein functions alone, requiring a systematic analysis of the intrinsic and extrinsic signals and the coordinated roles among them. Actin cytoskeleton organization and membrane vesicle trafficking are required during dendrite development, with actin providing tracks for vesicles and vesicle trafficking in turn providing material for actin assembly. In this review, we focus on these two basic biological processes and discuss the molecular mechanisms and their synergistic effects underlying the morphogenesis of neuronal dendrites. We also offer insights and discuss strategies for the potential preventive and therapeutic treatment of neuropsychiatric disorders.
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Affiliation(s)
- Wanting Wang
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, Jiangsu 210031, China
| | - Menglong Rui
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, Jiangsu 210031, China.
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3
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Zhang Y, Sung HH, Ziegler AB, Wu YC, Viais R, Sánchez-Huertas C, Kilo L, Agircan FG, Cheng YJ, Mouri K, Uemura T, Lüders J, Chien CT, Tavosanis G. Augmin complex activity finetunes dendrite morphology through non-centrosomal microtubule nucleation in vivo. J Cell Sci 2024; 137:jcs261512. [PMID: 38587100 PMCID: PMC11128282 DOI: 10.1242/jcs.261512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 04/03/2024] [Indexed: 04/09/2024] Open
Abstract
During development, neurons achieve a stereotyped neuron type-specific morphology, which relies on dynamic support by microtubules (MTs). An important player is the augmin complex (hereafter augmin), which binds to existing MT filaments and recruits the γ-tubulin ring complex (γ-TuRC), to form branched MTs. In cultured neurons, augmin is important for neurite formation. However, little is known about the role of augmin during neurite formation in vivo. Here, we have revisited the role of mammalian augmin in culture and then turned towards the class four Drosophila dendritic arborization (c4da) neurons. We show that MT density is maintained through augmin in cooperation with the γ-TuRC in vivo. Mutant c4da neurons show a reduction of newly emerging higher-order dendritic branches and in turn also a reduced number of their characteristic space-filling higher-order branchlets. Taken together, our data reveal a cooperative function for augmin with the γ-TuRC in forming enough MTs needed for the appropriate differentiation of morphologically complex dendrites in vivo.
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Affiliation(s)
- Yun Zhang
- German Center for Neurodegenerative Diseases (DZNE), Dynamics of Neuronal Circuits Group, Venusberg Campus 1 Building 99, 53127 Bonn, Germany
| | - Hsin-Ho Sung
- Institute of Molecular Biology, Academia Sinica, 11529 Taipei, Taiwan
| | - Anna B. Ziegler
- German Center for Neurodegenerative Diseases (DZNE), Dynamics of Neuronal Circuits Group, Venusberg Campus 1 Building 99, 53127 Bonn, Germany
| | - Ying-Chieh Wu
- Institute of Molecular Biology, Academia Sinica, 11529 Taipei, Taiwan
| | - Ricardo Viais
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Carlos Sánchez-Huertas
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Lukas Kilo
- German Center for Neurodegenerative Diseases (DZNE), Dynamics of Neuronal Circuits Group, Venusberg Campus 1 Building 99, 53127 Bonn, Germany
| | - Fikret Gürkan Agircan
- German Center for Neurodegenerative Diseases (DZNE), Dynamics of Neuronal Circuits Group, Venusberg Campus 1 Building 99, 53127 Bonn, Germany
| | - Ying-Ju Cheng
- Institute of Molecular Biology, Academia Sinica, 11529 Taipei, Taiwan
| | - Kousuke Mouri
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Tadashi Uemura
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
- Center for Living Systems Information Science, Kyoto University
| | - Jens Lüders
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Cheng-Ting Chien
- Institute of Molecular Biology, Academia Sinica, 11529 Taipei, Taiwan
| | - Gaia Tavosanis
- German Center for Neurodegenerative Diseases (DZNE), Dynamics of Neuronal Circuits Group, Venusberg Campus 1 Building 99, 53127 Bonn, Germany
- LIMES Institute, University of Bonn, 53115 Bonn, Germany
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4
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Liao M, Bird AD, Cuntz H, Howard J. Topology recapitulates morphogenesis of neuronal dendrites. Cell Rep 2023; 42:113268. [PMID: 38007691 PMCID: PMC10756852 DOI: 10.1016/j.celrep.2023.113268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 08/01/2023] [Accepted: 09/28/2023] [Indexed: 11/27/2023] Open
Abstract
Branching allows neurons to make synaptic contacts with large numbers of other neurons, facilitating the high connectivity of nervous systems. Neuronal arbors have geometric properties such as branch lengths and diameters that are optimal in that they maximize signaling speeds while minimizing construction costs. In this work, we asked whether neuronal arbors have topological properties that may also optimize their growth or function. We discovered that for a wide range of invertebrate and vertebrate neurons the distributions of their subtree sizes follow power laws, implying that they are scale invariant. The power-law exponent distinguishes different neuronal cell types. Postsynaptic spines and branchlets perturb scale invariance. Through simulations, we show that the subtree-size distribution depends on the symmetry of the branching rules governing arbor growth and that optimal morphologies are scale invariant. Thus, the subtree-size distribution is a topological property that recapitulates the functional morphology of dendrites.
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Affiliation(s)
- Maijia Liao
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Alex D Bird
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, 60528 Frankfurt am Main, Germany; ICAR3R-Interdisciplinary Centre for 3Rs in Animal Research, Faculty of Medicine, Justus Liebig University, 35390 Giessen, Germany
| | - Hermann Cuntz
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, 60528 Frankfurt am Main, Germany; ICAR3R-Interdisciplinary Centre for 3Rs in Animal Research, Faculty of Medicine, Justus Liebig University, 35390 Giessen, Germany
| | - Jonathon Howard
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT 06520, USA.
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Ouzounidis VR, Prevo B, Cheerambathur DK. Sculpting the dendritic landscape: Actin, microtubules, and the art of arborization. Curr Opin Cell Biol 2023; 84:102214. [PMID: 37544207 DOI: 10.1016/j.ceb.2023.102214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 06/20/2023] [Accepted: 07/05/2023] [Indexed: 08/08/2023]
Abstract
Dendrites are intricately designed neuronal compartments that play a vital role in the gathering and processing of sensory or synaptic inputs. Their diverse and elaborate structures are distinct features of neuronal organization and function. Central to the generation of these dendritic arbors is the neuronal cytoskeleton. In this review, we delve into the current progress toward our understanding of how dendrite arbors are generated and maintained, focusing on the role of the actin and microtubule cytoskeleton.
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Affiliation(s)
- Vasileios R Ouzounidis
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Bram Prevo
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Dhanya K Cheerambathur
- Wellcome Centre for Cell Biology & Institute of Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3BF, UK.
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6
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De Schutter E. Efficient simulation of neural development using shared memory parallelization. Front Neuroinform 2023; 17:1212384. [PMID: 37547492 PMCID: PMC10400717 DOI: 10.3389/fninf.2023.1212384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 06/30/2023] [Indexed: 08/08/2023] Open
Abstract
The Neural Development Simulator, NeuroDevSim, is a Python module that simulates the most important aspects of brain development: morphological growth, migration, and pruning. It uses an agent-based modeling approach inherited from the NeuroMaC software. Each cycle has agents called fronts execute model-specific code. In the case of a growing dendritic or axonal front, this will be a choice between extension, branching, or growth termination. Somatic fronts can migrate to new positions and any front can be retracted to prune parts of neurons. Collision detection prevents new or migrating fronts from overlapping with existing ones. NeuroDevSim is a multi-core program that uses an innovative shared memory approach to achieve parallel processing without messaging. We demonstrate linear strong parallel scaling up to 96 cores for large models and have run these successfully on 128 cores. Most of the shared memory parallelism is achieved without memory locking. Instead, cores have only write privileges to private sections of arrays, while being able to read the entire shared array. Memory conflicts are avoided by a coding rule that allows only active fronts to use methods that need writing access. The exception is collision detection, which is needed to avoid the growth of physically overlapping structures. For collision detection, a memory-locking mechanism was necessary to control access to grid points that register the location of nearby fronts. A custom approach using a serialized lock broker was able to manage both read and write locking. NeuroDevSim allows easy modeling of most aspects of neural development for models simulating a few complex or thousands of simple neurons or a mixture of both. Code available at https://github.com/CNS-OIST/NeuroDevSim.
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Affiliation(s)
- Erik De Schutter
- Computational Neuroscience Unit, Okinawa Institute of Science and Technology, Okinawa, Japan
- Department of Biomedical Sciences, University of Antwerp, Antwerpen, Belgium
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Lin C, Xu F, Zhang Y. Brain-wide dendrites in a near-optimal performance of dynamic range and information transmission. Sci Rep 2023; 13:7488. [PMID: 37160938 PMCID: PMC10170161 DOI: 10.1038/s41598-023-34454-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Accepted: 04/30/2023] [Indexed: 05/11/2023] Open
Abstract
Dendrites receive and process signals from other neurons. The range of signal intensities that can be robustly distinguished by dendrites is quantified by the dynamic range. We investigate the dynamic range and information transmission efficiency of dendrites in relation to dendritic morphology. We model dendrites in a neuron as multiple excitable binary trees connected to the soma where each node in a tree can be excited by external stimulus or by receiving signals transmitted from adjacent excited nodes. It has been known that larger dendritic trees have a higher dynamic range. We show that for dendritic tress of the same number of nodes, the dynamic range increases with the number of somatic branches and decreases with the asymmetry of dendrites, and the information transmission is more efficient for dendrites with more somatic branches. Moreover, our simulated data suggest that there is an exponential association (decay resp.) of overall relative energy consumption (dynamic range resp.) in relation to the number of somatic branches. This indicates that further increasing the number of somatic branches (e.g. beyond 10 somatic branches) has limited ability to improve the transmission efficiency. With brain-wide neuron digital reconstructions of the pyramidal cells, 90% of neurons have no more than 10 dendrites. These suggest that actual brain-wide dendritic morphology is near optimal in terms of both dynamic range and information transmission.
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Affiliation(s)
- Congping Lin
- School of Mathematics and Statistics and Center for Mathematical Sciences, Huazhong University of Science and Technology, Wuhan, China
- Hubei Key Lab of Engineering Modeling and Scientific Computing, Huazhong University of Science and Technology, Wuhan, China
| | - Fan Xu
- School of Mathematics and Statistics and Center for Mathematical Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Yiwei Zhang
- Department of Mathematics, Southern University of Science and Technology, Shenzhen, Guangdong, China.
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Nanda S, Bhattacharjee S, Cox DN, Ascoli GA. Local Microtubule and F-Actin Distributions Fully Constrain the Spatial Geometry of Drosophila Sensory Dendritic Arbors. Int J Mol Sci 2023; 24:6741. [PMID: 37047715 PMCID: PMC10095360 DOI: 10.3390/ijms24076741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 03/29/2023] [Accepted: 04/01/2023] [Indexed: 04/09/2023] Open
Abstract
Dendritic morphology underlies the source and processing of neuronal signal inputs. Morphology can be broadly described by two types of geometric characteristics. The first is dendrogram topology, defined by the length and frequency of the arbor branches; the second is spatial embedding, mainly determined by branch angles and straightness. We have previously demonstrated that microtubules and actin filaments are associated with arbor elongation and branching, fully constraining dendrogram topology. Here, we relate the local distribution of these two primary cytoskeletal components with dendritic spatial embedding. We first reconstruct and analyze 167 sensory neurons from the Drosophila larva encompassing multiple cell classes and genotypes. We observe that branches with a higher microtubule concentration tend to deviate less from the direction of their parent branch across all neuron types. Higher microtubule branches are also overall straighter. F-actin displays a similar effect on angular deviation and branch straightness, but not as consistently across all neuron types as microtubule. These observations raise the question as to whether the associations between cytoskeletal distributions and arbor geometry are sufficient constraints to reproduce type-specific dendritic architecture. Therefore, we create a computational model of dendritic morphology purely constrained by the cytoskeletal composition measured from real neurons. The model quantitatively captures both spatial embedding and dendrogram topology across all tested neuron groups. These results suggest a common developmental mechanism regulating diverse morphologies, where the local cytoskeletal distribution can fully specify the overall emergent geometry of dendritic arbors.
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Affiliation(s)
- Sumit Nanda
- Center for Neural Informatics, Structures, and Plasticity and Neuroscience Program, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA 22030, USA;
| | - Shatabdi Bhattacharjee
- Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA; (S.B.); (D.N.C.)
| | - Daniel N. Cox
- Neuroscience Institute, Georgia State University, Atlanta, GA 30303, USA; (S.B.); (D.N.C.)
| | - Giorgio A. Ascoli
- Center for Neural Informatics, Structures, and Plasticity and Neuroscience Program, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA 22030, USA;
- Bioengineering Department, College of Engineering and Computing, George Mason University, Fairfax, VA 22032, USA
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Boivin JC, Zhu J, Ohyama T. Nociception in fruit fly larvae. FRONTIERS IN PAIN RESEARCH 2023; 4:1076017. [PMID: 37006412 PMCID: PMC10063880 DOI: 10.3389/fpain.2023.1076017] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 02/28/2023] [Indexed: 03/19/2023] Open
Abstract
Nociception, the process of encoding and processing noxious or painful stimuli, allows animals to detect and avoid or escape from potentially life-threatening stimuli. Here, we provide a brief overview of recent technical developments and studies that have advanced our understanding of the Drosophila larval nociceptive circuit and demonstrated its potential as a model system to elucidate the mechanistic basis of nociception. The nervous system of a Drosophila larva contains roughly 15,000 neurons, which allows for reconstructing the connectivity among them directly by transmission electron microscopy. In addition, the availability of genetic tools for manipulating the activity of individual neurons and recent advances in computational and high-throughput behavior analysis methods have facilitated the identification of a neural circuit underlying a characteristic nocifensive behavior. We also discuss how neuromodulators may play a key role in modulating the nociceptive circuit and behavioral output. A detailed understanding of the structure and function of Drosophila larval nociceptive neural circuit could provide insights into the organization and operation of pain circuits in mammals and generate new knowledge to advance the development of treatment options for pain in humans.
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Affiliation(s)
- Jean-Christophe Boivin
- Department of Biology, McGill University, Montreal, QC, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Jiayi Zhu
- Department of Biology, McGill University, Montreal, QC, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Tomoko Ohyama
- Department of Biology, McGill University, Montreal, QC, Canada
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada
- Correspondence: Tomoko Ohyama
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Nanda S, Bhattacharjee S, Cox DN, Ascoli GA. Local microtubule and F-actin distributions fully determine the spatial geometry of Drosophila sensory dendritic arbors. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.24.529978. [PMID: 36909461 PMCID: PMC10002631 DOI: 10.1101/2023.02.24.529978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Dendritic morphology underlies the source and processing of neuronal signal inputs. Morphology can be broadly described by two types of geometric characteristics. The first is dendrogram topology, defined by the length and frequency of the arbor branches; the second is spatial embedding, mainly determined by branch angles and tortuosity. We have previously demonstrated that microtubules and actin filaments are associated with arbor elongation and branching, fully constraining dendrogram topology. Here we relate the local distribution of these two primary cytoskeletal components with dendritic spatial embedding. We first reconstruct and analyze 167 sensory neurons from the Drosophila larva encompassing multiple cell classes and genotypes. We observe that branches with higher microtubule concentration are overall straighter and tend to deviate less from the direction of their parent branch. F-actin displays a similar effect on the angular deviation from the parent branch direction, but its influence on branch tortuosity varies by class and genotype. We then create a computational model of dendritic morphology purely constrained by the cytoskeletal composition imaged from real neurons. The model quantitatively captures both spatial embedding and dendrogram topology across all tested neuron groups. These results suggest a common developmental mechanism regulating diverse morphologies, where the local cytoskeletal distribution can fully specify the overall emergent geometry of dendritic arbors.
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