1. Neuroscience
Download icon

Phasic and tonic neuron ensemble codes for stimulus-environment conjunctions in the lateral entorhinal cortex

  1. Maryna Pilkiw
  2. Nathan Insel
  3. Younghua Cui
  4. Caitlin Finney
  5. Mark D Morrissey
  6. Kaori Takehara-Nishiuchi  Is a corresponding author
  1. University of Toronto, Canada
  2. University of Montana, United States
  3. University or Toronto, Canada
Research Article
  • Cited 11
  • Views 2,254
  • Annotations
Cite this article as: eLife 2017;6:e28611 doi: 10.7554/eLife.28611

Abstract

The lateral entorhinal cortex (LEC) is thought to bind sensory events with the environment where they took place. To compare the relative influence of transient events and temporally stable environmental stimuli on the firing of LEC cells, we recorded neuron spiking patterns in the region during blocks of a trace eyeblink conditioning paradigm performed in two environments and with different conditioning stimuli. Firing rates of some neurons were phasically selective for conditioned stimuli in a way that depended on which room the rat was in; nearly all neurons were tonically selective for environments in a way that depended on which stimuli had been presented in those environments. As rats moved from one environment to another, tonic neuron ensemble activity exhibited prospective information about the conditioned stimulus associated with the environment. Thus, the LEC formed phasic and tonic codes for event-environment associations, thereby accurately differentiating multiple experiences with overlapping features.

Article and author information

Author details

  1. Maryna Pilkiw

    Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-1200-1708
  2. Nathan Insel

    Department of Psychology, University of Montana, Missoula, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Younghua Cui

    Department of Psychology, University of Toronto, Toronto, Canada
    Competing interests
    The authors declare that no competing interests exist.
  4. Caitlin Finney

    Department of Psychology, University of Toronto, Toronto, Canada
    Competing interests
    The authors declare that no competing interests exist.
  5. Mark D Morrissey

    Department of Psychology, University or Toronto, Toronto, Canada
    Competing interests
    The authors declare that no competing interests exist.
  6. Kaori Takehara-Nishiuchi

    Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
    For correspondence
    takehara@psych.utoronto.ca
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-7282-7838

Funding

Natural Sciences and Engineering Research Council of Canada (RGPIN-2015-05458)

  • Kaori Takehara-Nishiuchi

Canadian Institutes of Health Research (MOP-133693)

  • Kaori Takehara-Nishiuchi

Canada Foundation for Innovation (25026)

  • Kaori Takehara-Nishiuchi

Natural Sciences and Engineering Research Council of Canada (396157093)

  • Maryna Pilkiw

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Animal experimentation: All surgical and experimental procedures were approved by the Animal Care and Use Committee at the University of Toronto (protocol number: 20011400).

Reviewing Editor

  1. Geoffrey Schoenbaum, National Institutes of Health, United States

Publication history

  1. Received: May 13, 2017
  2. Accepted: July 5, 2017
  3. Accepted Manuscript published: July 6, 2017 (version 1)
  4. Version of Record published: July 31, 2017 (version 2)

Copyright

© 2017, Pilkiw 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

  • 2,254
    Page views
  • 325
    Downloads
  • 11
    Citations

Article citation count generated by polling the highest count across the following sources: Crossref, Scopus, PubMed Central.

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)

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

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

Further reading

    1. Cell Biology
    2. Neuroscience
    Rene Solano Fonseca et al.
    Research Article Updated

    Concussion is associated with a myriad of deleterious immediate and long-term consequences. Yet the molecular mechanisms and genetic targets promoting the selective vulnerability of different neural subtypes to dysfunction and degeneration remain unclear. Translating experimental models of blunt force trauma in C. elegans to concussion in mice, we identify a conserved neuroprotective mechanism in which reduction of mitochondrial electron flux through complex IV suppresses trauma-induced degeneration of the highly vulnerable dopaminergic neurons. Reducing cytochrome C oxidase function elevates mitochondrial-derived reactive oxygen species, which signal through the cytosolic hypoxia inducing transcription factor, Hif1a, to promote hyperphosphorylation and inactivation of the pyruvate dehydrogenase, PDHE1α. This critical enzyme initiates the Warburg shunt, which drives energetic reallocation from mitochondrial respiration to astrocyte-mediated glycolysis in a neuroprotective manner. These studies demonstrate a conserved process in which glycolytic preconditioning suppresses Parkinson-like hypersensitivity of dopaminergic neurons to trauma-induced degeneration via redox signaling and the Warburg effect.

    1. Biochemistry and Chemical Biology
    2. Neuroscience
    Lloyd Davis et al.
    Tools and Resources Updated

    Synthetic strategies for optically controlling gene expression may enable the precise spatiotemporal control of genes in any combination of cells that cannot be targeted with specific promoters. We develop an improved genetic code expansion system in Caenorhabditis elegans and use it to create a photoactivatable Cre recombinase. We laser-activate Cre in single neurons within a bilaterally symmetric pair to selectively switch on expression of a loxP-controlled optogenetic channel in the targeted neuron. We use the system to dissect, in freely moving animals, the individual contributions of the mechanosensory neurons PLML/PLMR to the C. elegans touch response circuit, revealing distinct and synergistic roles for these neurons. We thus demonstrate how genetic code expansion and optical targeting can be combined to break the symmetry of neuron pairs and dissect behavioural outputs of individual neurons that cannot be genetically targeted.