Patch-clamp recordings from white matter glia in thin longitudinal slices of adult rat spinal cord

Raad Nashmi, Alexander A. Velumian, Induk Chung, Liang Zhang, Sandeep K. Agrawal, Michael G. Fehlings

Research output: Contribution to journalArticlepeer-review

17 Scopus citations

Abstract

We developed a technique of whole cell patch-clamp recordings from white matter oligodendrocytes and astrocytes in 200-250 μm-thick horizontal slices of adult (>2 months, 240-260 g) rat thoracic spinal cord. The viability of the white matter, sectioned in Na+-free, low Ca2+ media, and the function of axons were preserved for >8 h, as demonstrated by the propagation of TTX-sensitive compound action potentials (CAPs) and the sensitivity of their refractory period to K+ channel blocker 4-aminopyridine (1 mM). Glial cells were visually identified within the slices with a 40× water immersion objective using infra-red differential interference contrast (IR-DIC) video microscopy, and the details of their morphology were further elucidated after filling the cells with Lucifer Yellow or Alexa 350 fluorescent dyes during whole-cell recording. Using voltage steps and ramps, we revealed pronounced non-linearity of I-V relationships in both oligodendrocytes and astrocytes. Both types of cells expressed TEA-sensitive outward delayed rectifier-type currents activated at positive voltages but showed little, if any, signs of inward rectification at voltages up to -140 mV. At -70 mV holding voltage, bath-applied kainic acid (100 μM) activated inward currents in both types of cells. This novel horizontal slice preparation of adult rat thoracic cord will facilitate the examination of mature glial cell physiology, glial-axonal signaling and the pathophysiology of spinal cord trauma and ischemia.

Original languageEnglish (US)
Pages (from-to)159-166
Number of pages8
JournalJournal of Neuroscience Methods
Volume117
Issue number2
DOIs
StatePublished - Jun 30 2002

Keywords

  • Astrocyte
  • Axons
  • Electrophysiology
  • Oligodendrocyte
  • Patch-clamp
  • Slice
  • Spinal cord

ASJC Scopus subject areas

  • Neuroscience(all)

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