Amyotrophic lateral sclerosis: Serum factors enhance spontaneous and evoked transmitter release at the neuromuscular junction

Thomas J. O'Shaughnessy, Haidun Yan, Jimok Kim, Eric H. Middlekauff, Kwang W. Lee, Lawrence H. Phillips, Jun Kim, Yong I. Kim

Research output: Contribution to journalArticle

23 Scopus citations


Sera from 30 patients with sporadic amyotrophic lateral sclerosis (ALS) were tested to determine their effects at the neuromuscular junction. Spontaneous transmitter release was significantly increased, as evidenced by a 151% increase in MEPP frequency, by sera from 16 ALS patients. In addition, 16 patients sera elevated EEP quantal content by an average of 89%. Eleven sera produced both effects. There was no consistent change in MEPP amplitude or time course, indicating the absence of a humoral effect on postjunctional ACh receptors or endplate membrane function. These results suggest that a portion of the sporadic ALS patient population possess serum factors that can alter presynaptic function of the motor nerve terminal. Evidence from the present experiments indicates that alterations at the neuromuscular junction are a result of a combination of increased Ca2+ influx into the cell and an independent increase in intracellular calcium concentration.

Original languageEnglish (US)
Pages (from-to)81-90
Number of pages10
JournalMuscle and Nerve
Issue number1
StatePublished - Jan 29 1998



  • Amyotrophic lateral sclerosis
  • Calcium channels
  • Evoked transmitter release
  • Neuromuscular junction
  • Quantal content

ASJC Scopus subject areas

  • Physiology
  • Clinical Neurology
  • Cellular and Molecular Neuroscience
  • Physiology (medical)

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