TY - JOUR
T1 - Patch-clamp recordings from white matter glia in thin longitudinal slices of adult rat spinal cord
AU - Nashmi, Raad
AU - Velumian, Alexander A.
AU - Chung, Induk
AU - Zhang, Liang
AU - Agrawal, Sandeep K.
AU - Fehlings, Michael G.
N1 - Funding Information:
Raad Nashmi was supported by the Rick Hansen Man in Motion Foundation, Ontario Neurotrauma Foundation Studentship award from the Ontario Government and the Merit Scholarship. Michael G. Fehlings is supported by a Career Investigator Award from the Ontario Ministry of Health. The authors thank Dr Yu Zhang and Dr Chi-Ping Wu for assistance and helpful discussions. This work was made possible by an equipment and operating grant from the Ontario Neurotrauma Foundation. Operating grant support by the Canadian Institutes of Health Research is gratefully acknowledged (Michael G. Fehlings).
PY - 2002/6/30
Y1 - 2002/6/30
N2 - 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.
AB - 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.
KW - Astrocyte
KW - Axons
KW - Electrophysiology
KW - Oligodendrocyte
KW - Patch-clamp
KW - Slice
KW - Spinal cord
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U2 - 10.1016/S0165-0270(02)00096-1
DO - 10.1016/S0165-0270(02)00096-1
M3 - Article
C2 - 12100981
AN - SCOPUS:0037199115
SN - 0165-0270
VL - 117
SP - 159
EP - 166
JO - Journal of Neuroscience Methods
JF - Journal of Neuroscience Methods
IS - 2
ER -