Changes in the excitability of neocortical neurons in a mouse model of amyotrophic lateral sclerosis are not specific to corticospinal neurons and are modulated by advancing disease

Juhyun Kim, Ethan G. Hughes, Ashwin S. Shetty, Paola Arlotta, Loyal Goff, Dwight E Bergles, Solange P Brown

Research output: Contribution to journalArticle

Abstract

Cell type-specific changes in neuronal excitability have been proposed to contribute to the selective degeneration of corticospinal neurons in amyotrophic lateral sclerosis (ALS) and to neocortical hyperexcitability, a prominent feature of both inherited and sporadic variants of the disease, but the mechanisms underlying selective loss of specific cell types in ALS are not known. We analyzed the physiological properties of distinct classes of cortical neurons in the motor cortex of hSOD1G93A mice of both sexes and found that they all exhibit increases in intrinsic excitability that depend on disease stage. Targeted recordings and in vivo calcium imaging further revealed that neurons adapt their functional properties to normalize cortical excitability as the disease progresses. Although different neuron classes all exhibited increases in intrinsic excitability, transcriptional profiling indicated that the molecular mechanisms underlying these changes are cell type specific. The increases in excitability in both excitatory and inhibitory cortical neurons show that selective dysfunction of neuronal cell types cannot account for the specific vulnerability of corticospinal motor neurons in ALS. Furthermore, the stagedependent alterations in neuronal function highlight the ability of cortical circuits to adapt as disease progresses. These findings show that both disease stage and cell type must be considered when developing therapeutic strategies for treating ALS.

Original languageEnglish (US)
Pages (from-to)9037-9053
Number of pages17
JournalJournal of Neuroscience
Volume37
Issue number37
DOIs
StatePublished - 2017

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Keywords

  • Corticocortical neuron
  • Corticospinal neuron
  • Interneuron
  • Intrinsic excitability
  • RNA sequencing
  • Two-photon imaging

ASJC Scopus subject areas

  • Neuroscience(all)

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