Distinct modes of endocytotic presynaptic membrane and protein uptake at the calyx of Held terminal of rats and mice

  1. Yuji Okamoto
  2. Noa Lipstein
  3. Yunfeng Hua
  4. Kun-Han Lin
  5. Nils Brose
  6. Takeshi Sakaba
  7. Mitsuharu Midorikawa  Is a corresponding author
  1. Doshisha University, Japan
  2. Max Planck Institute of Experimental Medicine, Germany
  3. Max Planck Institute of Brain Research, Germany
  4. Max-Planck-Institute for Biophysical Chemistry, Germany

Abstract

Neurotransmitter is released at synapses by fusion of synaptic vesicles with the plasma membrane. To sustain synaptic transmission, compensatory retrieval of membranes and vesicular proteins is essential. We combined capacitance measurements and pH-imaging via pH-sensitive vesicular protein marker (anti-synaptotagmin2-cypHer5E), and compared the retrieval kinetics of membranes and vesicular proteins at the calyx of Held synapse. Membrane and Syt2 were retrieved with a similar time course when slow endocytosis was elicited. When fast endocytosis was elicited, Syt2 was still retrieved together with the membrane, but endocytosed organelle re-acidification was slowed down, which provides strong evidence for two distinct endocytotic pathways. Strikingly, CaM inhibitors or the inhibition of the Ca2+-calmodulin-Munc13-1 signaling pathway only impaired the uptake of Syt2 while leaving membrane retrieval intact, indicating different recycling mechanisms for membranes and vesicle proteins. Our data identify a novel mechanism of stimulus- and Ca2+-dependent regulation of coordinated endocytosis of synaptic membranes and vesicle proteins.

Article and author information

Author details

  1. Yuji Okamoto

    Graduate School of Brain Science, Doshisha University, Kyoto, Japan
    Competing interests
    The authors declare that no competing interests exist.
  2. Noa Lipstein

    Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
    Competing interests
    The authors declare that no competing interests exist.
  3. Yunfeng Hua

    Department of Connectomics, Max Planck Institute of Brain Research, Frankfurt, Germany
    Competing interests
    The authors declare that no competing interests exist.
  4. Kun-Han Lin

    Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
    Competing interests
    The authors declare that no competing interests exist.
  5. Nils Brose

    Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
    Competing interests
    The authors declare that no competing interests exist.
  6. Takeshi Sakaba

    Graduate School of Brain Science, Doshisha University, Kyoto, Japan
    Competing interests
    The authors declare that no competing interests exist.
  7. Mitsuharu Midorikawa

    Graduate School of Brain Science, Doshisha University, Kyoto, Japan
    For correspondence
    mmidorik@mail.doshisha.ac.jp
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. Christian Rosenmund, Charité, Universitätsmedizin Berlin, Germany

Ethics

Animal experimentation: Animal care and animal procedures were conducted in accordance with the guidelines of the Physiological Society of Japan, and were approved by the Doshisha University Committee for Regulation on the Conduct of Animal Experiments and Related Activities. All efforts were taken to minimize animal numbers. The generation, maintenance, and use of the Munc13-1W464R mice were approved by the responsible local government organization (Niedersächsisches Landesamt für Verbraucherschutz und Lebensmittelsicherheit, permissions 33.9.42502-04-13/1359 and 33.19-42502-04-15/1817).

Version history

  1. Received: January 22, 2016
  2. Accepted: May 6, 2016
  3. Accepted Manuscript published: May 7, 2016 (version 1)
  4. Version of Record published: June 29, 2016 (version 2)

Copyright

© 2016, Okamoto et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 2,053
    views
  • 614
    downloads
  • 14
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Yuji Okamoto
  2. Noa Lipstein
  3. Yunfeng Hua
  4. Kun-Han Lin
  5. Nils Brose
  6. Takeshi Sakaba
  7. Mitsuharu Midorikawa
(2016)
Distinct modes of endocytotic presynaptic membrane and protein uptake at the calyx of Held terminal of rats and mice
eLife 5:e14643.
https://doi.org/10.7554/eLife.14643

Share this article

https://doi.org/10.7554/eLife.14643

Further reading

    1. Cell Biology
    2. Neuroscience
    Mariana I Tsap, Andriy S Yatsenko ... Halyna R Shcherbata
    Research Article Updated

    Mutations in Drosophila Swiss cheese (SWS) gene or its vertebrate orthologue neuropathy target esterase (NTE) lead to progressive neuronal degeneration in flies and humans. Despite its enzymatic function as a phospholipase is well established, the molecular mechanism responsible for maintaining nervous system integrity remains unclear. In this study, we found that NTE/SWS is present in surface glia that forms the blood-brain barrier (BBB) and that NTE/SWS is important to maintain its structure and permeability. Importantly, BBB glia-specific expression of Drosophila NTE/SWS or human NTE in the sws mutant background fully rescues surface glial organization and partially restores BBB integrity, suggesting a conserved function of NTE/SWS. Interestingly, sws mutant glia showed abnormal organization of plasma membrane domains and tight junction rafts accompanied by the accumulation of lipid droplets, lysosomes, and multilamellar bodies. Since the observed cellular phenotypes closely resemble the characteristics described in a group of metabolic disorders known as lysosomal storage diseases (LSDs), our data established a novel connection between NTE/SWS and these conditions. We found that mutants with defective BBB exhibit elevated levels of fatty acids, which are precursors of eicosanoids and are involved in the inflammatory response. Also, as a consequence of a permeable BBB, several innate immunity factors are upregulated in an age-dependent manner, while BBB glia-specific expression of NTE/SWS normalizes inflammatory response. Treatment with anti-inflammatory agents prevents the abnormal architecture of the BBB, suggesting that inflammation contributes to the maintenance of a healthy brain barrier. Considering the link between a malfunctioning BBB and various neurodegenerative diseases, gaining a deeper understanding of the molecular mechanisms causing inflammation due to a defective BBB could help to promote the use of anti-inflammatory therapies for age-related neurodegeneration.

    1. Neuroscience
    Mohsen Sadeghi, Reza Sharif Razavian ... Dagmar Sternad
    Research Article

    Natural behaviors have redundancy, which implies that humans and animals can achieve their goals with different strategies. Given only observations of behavior, is it possible to infer the control objective that the subject is employing? This challenge is particularly acute in animal behavior because we cannot ask or instruct the subject to use a particular strategy. This study presents a three-pronged approach to infer an animal’s control objective from behavior. First, both humans and monkeys performed a virtual balancing task for which different control strategies could be utilized. Under matched experimental conditions, corresponding behaviors were observed in humans and monkeys. Second, a generative model was developed that represented two main control objectives to achieve the task goal. Model simulations were used to identify aspects of behavior that could distinguish which control objective was being used. Third, these behavioral signatures allowed us to infer the control objective used by human subjects who had been instructed to use one control objective or the other. Based on this validation, we could then infer objectives from animal subjects. Being able to positively identify a subject’s control objective from observed behavior can provide a powerful tool to neurophysiologists as they seek the neural mechanisms of sensorimotor coordination.