Non-linear developmental trajectory of electrical phenotype in rat substantia nigra pars compacta dopaminergic neurons

  1. Martial A Dufour
  2. Adele Woodhouse
  3. Julien Amendola
  4. Jean-Marc Goaillard  Is a corresponding author
  1. Inserm UMR 1072, Université de la Méditerranée, France
  2. University of Tasmania, Australia

Abstract

Neurons have complex electrophysiological properties, however, it is often difficult to determine which properties are the most relevant to neuronal function. By combining current-clamp measurements of electrophysiological properties with multi-variate analysis (hierarchical clustering, principal component analysis), we were able to characterize the postnatal development of substantia nigra dopaminergic neurons' electrical phenotype in an unbiased manner, such that subtle changes in phenotype could be analyzed. We show that the intrinsic electrical phenotype of these neurons follows a non-linear trajectory reaching maturity by postnatal day 14, with two developmental transitions occurring between postnatal days 3-5 and 9-11. This approach also predicted which parameters play a critical role in phenotypic variation, enabling us to determine (using pharmacology, dynamic-clamp) that changes in the leak, sodium and calcium-activated potassium currents are central to these two developmental transitions. This analysis enables an unbiased definition of neuronal type/phenotype that is applicable to a range of research questions.

Article and author information

Author details

  1. Martial A Dufour

    Inserm UMR 1072, Université de la Méditerranée, Marseille, France
    Competing interests
    The authors declare that no competing interests exist.
  2. Adele Woodhouse

    University of Tasmania, Hobart, Australia
    Competing interests
    The authors declare that no competing interests exist.
  3. Julien Amendola

    Inserm UMR 1072, Université de la Méditerranée, Marseille, France
    Competing interests
    The authors declare that no competing interests exist.
  4. Jean-Marc Goaillard

    Inserm UMR 1072, Université de la Méditerranée, Marseille, France
    For correspondence
    jean-marc.goaillard@univ-amu.fr
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. Ronald L Calabrese, Emory University, United States

Ethics

Animal experimentation: All experiments were performed according to the European and institutional guidelines for the care and use of laboratory animals (Council Directive 86/609/EEC and French National Research Council).

Version history

  1. Received: July 17, 2014
  2. Accepted: October 19, 2014
  3. Accepted Manuscript published: October 20, 2014 (version 1)
  4. Accepted Manuscript updated: October 23, 2014 (version 2)
  5. Version of Record published: November 25, 2014 (version 3)

Copyright

© 2014, Dufour 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

  • 2,214
    views
  • 301
    downloads
  • 29
    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. Martial A Dufour
  2. Adele Woodhouse
  3. Julien Amendola
  4. Jean-Marc Goaillard
(2014)
Non-linear developmental trajectory of electrical phenotype in rat substantia nigra pars compacta dopaminergic neurons
eLife 3:e04059.
https://doi.org/10.7554/eLife.04059

Share this article

https://doi.org/10.7554/eLife.04059

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.