Enhancement of the releases of GABA and glycine during ischemia in rat spinal dorsal horn.
The present study examined a change in spontaneous inhibitory postsynaptic currents (sIPSCs) following ischemia in substantia gelatinosa (SG) neurons of adult rat spinal cord slices by using the whole-cell patch-clamp technique. At about 10 min after superfusion of an oxygen- and glucose-free medium, sIPSCs were remarkably increased in amplitude and frequency when compared with those in the control. In a phase of the increase in sIPSC activities, GABAergic and glycinergic sIPSCs, which were observed in the presence of strychnine and bicuculline, respectively, with TTX, were increased greatly in frequency with a minimal change in their amplitudes. It is concluded that the in vitro ischemia increases the spontaneous quantal releases of GABA and glycine to SG neurons from nerve terminals; a part of this enhancement is possibly due to an increase in spontaneous activities of inhibitory interneurons. GABA released thus might serve to inhibit the release of l-glutamate from nerve terminals.
Kawasaki
Yasuhiko
Y
Department of Physiology, Saga Medical School, Saga 849-8501, Japan.
Fujita
Tsugumi
T
Kumamoto
Eiichi
E
D000818:Animals; D002478:Cells, Cultured; D004553:Electric Conductivity; D005998:Glycine / Q000378:metabolism*; D008297:Male; D009433:Neural Inhibition; D018408:Patch-Clamp Techniques; D020671:Posterior Horn Cells / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D020760:Spinal Cord Ischemia / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D005680:gamma-Aminobutyric Acid; D005998:Glycine