Hyperexcitability in synaptic and firing activities of spinal motoneurons in an adult mouse model of amyotrophic lateral sclerosis

Mingchen Jiang*, Adesoji Adimula, Derin Birch, Cj Heckman

*Corresponding author for this work

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Hyperexcitability is hypothesized to contribute to the degeneration of spinal motoneurons (MNs) in amyotrophic lateral sclerosis (ALS). Studies, thus far, have not linked hyperexcitability to the intrinsic properties of MNs in the adult ALS mouse model with the G93A-mutated SOD1 protein (mSOD1G93A). In this study, we obtained two types of measurements: ventral root recordings to assess motor output and intracellular recordings to assess synaptic properties of individual MNs. All studies were carried out in an in vitro preparation of the sacral spinal cords of mSOD1G93A mice and their non-transgenic (NT) littermates, both in the age range of 50–90 days. Ventral root recordings revealed that maximum compound action potentials (coAPs) evoked by a short-train stimulation of corresponding dorsal roots were similar between the two types of mice. Although the progressive depression of coAPs was present during the train stimulation in all recordings, the coAP depression in mSOD1G93A mice was to a lesser extent, which suggests an increased firing tendency in mSOD1G93A MNs. Intracellular recordings showed no changes in fast excitatory postsynaptic potentials (EPSPs) in mSOD1G93A MNs. However, recording did show that oscillating EPSPs (oEPSPs) were induced by poly-EPSPs at a higher frequency and by less-intense electrical stimulation in mSOD1G93A MNs. These oEPSPs were dependent upon the activities of spinal network and N-methyl-D-aspartate receptors (NMDARs), and were subjected to riluzole modulation. Taken together, these findings revealed abnormal electrophysiology in mSOD1G93A MNs that could underlie ALS excitotoxicity.

Original languageEnglish (US)
Pages (from-to)33-46
Number of pages14
JournalNeuroscience
Volume362
DOIs
StatePublished - Oct 24 2017

Fingerprint

Amyotrophic Lateral Sclerosis
Motor Neurons
Excitatory Postsynaptic Potentials
Spinal Nerve Roots
Action Potentials
Spinal Cord
Riluzole
Electrophysiology
N-Methyl-D-Aspartate Receptors
Electric Stimulation

Keywords

  • NMDA receptor
  • amyotrophic lateral sclerosis
  • hyperexcitability
  • short-term plasticity
  • spinal motoneurons
  • synaptic transmission

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

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title = "Hyperexcitability in synaptic and firing activities of spinal motoneurons in an adult mouse model of amyotrophic lateral sclerosis",
abstract = "Hyperexcitability is hypothesized to contribute to the degeneration of spinal motoneurons (MNs) in amyotrophic lateral sclerosis (ALS). Studies, thus far, have not linked hyperexcitability to the intrinsic properties of MNs in the adult ALS mouse model with the G93A-mutated SOD1 protein (mSOD1G93A). In this study, we obtained two types of measurements: ventral root recordings to assess motor output and intracellular recordings to assess synaptic properties of individual MNs. All studies were carried out in an in vitro preparation of the sacral spinal cords of mSOD1G93A mice and their non-transgenic (NT) littermates, both in the age range of 50–90 days. Ventral root recordings revealed that maximum compound action potentials (coAPs) evoked by a short-train stimulation of corresponding dorsal roots were similar between the two types of mice. Although the progressive depression of coAPs was present during the train stimulation in all recordings, the coAP depression in mSOD1G93A mice was to a lesser extent, which suggests an increased firing tendency in mSOD1G93A MNs. Intracellular recordings showed no changes in fast excitatory postsynaptic potentials (EPSPs) in mSOD1G93A MNs. However, recording did show that oscillating EPSPs (oEPSPs) were induced by poly-EPSPs at a higher frequency and by less-intense electrical stimulation in mSOD1G93A MNs. These oEPSPs were dependent upon the activities of spinal network and N-methyl-D-aspartate receptors (NMDARs), and were subjected to riluzole modulation. Taken together, these findings revealed abnormal electrophysiology in mSOD1G93A MNs that could underlie ALS excitotoxicity.",
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Hyperexcitability in synaptic and firing activities of spinal motoneurons in an adult mouse model of amyotrophic lateral sclerosis. / Jiang, Mingchen; Adimula, Adesoji; Birch, Derin; Heckman, Cj.

In: Neuroscience, Vol. 362, 24.10.2017, p. 33-46.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Hyperexcitability in synaptic and firing activities of spinal motoneurons in an adult mouse model of amyotrophic lateral sclerosis

AU - Jiang, Mingchen

AU - Adimula, Adesoji

AU - Birch, Derin

AU - Heckman, Cj

PY - 2017/10/24

Y1 - 2017/10/24

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AB - Hyperexcitability is hypothesized to contribute to the degeneration of spinal motoneurons (MNs) in amyotrophic lateral sclerosis (ALS). Studies, thus far, have not linked hyperexcitability to the intrinsic properties of MNs in the adult ALS mouse model with the G93A-mutated SOD1 protein (mSOD1G93A). In this study, we obtained two types of measurements: ventral root recordings to assess motor output and intracellular recordings to assess synaptic properties of individual MNs. All studies were carried out in an in vitro preparation of the sacral spinal cords of mSOD1G93A mice and their non-transgenic (NT) littermates, both in the age range of 50–90 days. Ventral root recordings revealed that maximum compound action potentials (coAPs) evoked by a short-train stimulation of corresponding dorsal roots were similar between the two types of mice. Although the progressive depression of coAPs was present during the train stimulation in all recordings, the coAP depression in mSOD1G93A mice was to a lesser extent, which suggests an increased firing tendency in mSOD1G93A MNs. Intracellular recordings showed no changes in fast excitatory postsynaptic potentials (EPSPs) in mSOD1G93A MNs. However, recording did show that oscillating EPSPs (oEPSPs) were induced by poly-EPSPs at a higher frequency and by less-intense electrical stimulation in mSOD1G93A MNs. These oEPSPs were dependent upon the activities of spinal network and N-methyl-D-aspartate receptors (NMDARs), and were subjected to riluzole modulation. Taken together, these findings revealed abnormal electrophysiology in mSOD1G93A MNs that could underlie ALS excitotoxicity.

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KW - short-term plasticity

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KW - synaptic transmission

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