Hyperexcitability in synaptic and firing activities of spinal motoneurons in an adult mouse model of amyotrophic lateral sclerosis
| Autor: | Derin Birch, M. C. Jiang, Adesoji Adimula, Charles J. Heckman |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Excitotoxicity Action Potentials Stimulation Mice Transgenic Neurotransmission Biology Inhibitory postsynaptic potential medicine.disease_cause Receptors N-Methyl-D-Aspartate Article Tissue Culture Techniques 03 medical and health sciences 0302 clinical medicine medicine Animals Receptors AMPA Amyotrophic lateral sclerosis Motor Neurons Riluzole General Neuroscience Amyotrophic Lateral Sclerosis nutritional and metabolic diseases Excitatory Postsynaptic Potentials medicine.disease Electric Stimulation Electrophysiology 030104 developmental biology Spinal Cord Synapses Excitatory postsynaptic potential Calcium Spinal Nerve Roots Neuroscience Excitatory Amino Acid Antagonists 030217 neurology & neurosurgery medicine.drug |
| Popis: | 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 (mSOD1 G93A ). 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 mSOD1 G93A 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 mSOD1 G93A mice was to a lesser extent, which suggests an increased firing tendency in mSOD1 G93A MNs. Intracellular recordings showed no changes in fast excitatory postsynaptic potentials (EPSPs) in mSOD1 G93A 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 mSOD1 G93A 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 mSOD1 G93A MNs that could underlie ALS excitotoxicity. |
| Databáze: | OpenAIRE |
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