Run-down of the GABAA response under experimental ischaemia in acutely dissociated CA1 pyramidal neurones of the rat

The Journal of Physiology
N HarataN Akaike

Abstract

1. The effect of experimental ischaemia on the response to gamma-aminobutyric acid (GABA) was assessed in acutely dissociated CA1 pyramidal neurones of rats, using the patch-clamp technique. 2. Rapid application of 3 x 10(-5) M GABA induced a bicuculline-sensitive inward Cl- current (IGABA) at a holding potential (Vh) of -44 mV. The peak amplitude of IGABA showed a time-dependent decrease (run-down) when it was recorded with the conventional whole-cell mode without internal ATP. The run-down was not observed when the intracellular ATP concentration ([ATP]i) was maintained by the nystatin-perforated recording with an intracellular Na+ concentration ([Na+]i) of 0 mM. 3. When [Na+]i was increased to more than 30 mM, the IGABA run-down was observed even with the nystatin-perforated recording. 4. The IGABA run-down observed at 60 mM [Na+]i with the nystatin method was further enhanced under experimental ischaemia without changes in the reversal potential of IGABA. The enhanced run-down was suppressed by application of the Na+,K(+)-ATPase inhibitors, ouabain and SPAI-1. 5. IGABA run-down during ischaemia was also accompanied by an outward holding current and a concomitant increase in intracellular free Ca2+ concentration ([Ca2+]i) in...Continue Reading

Citations

Feb 21, 2004·Neuropharmacology·Lei GaoL John Greenfield
Apr 12, 2001·Journal of Neurochemistry·R D Schwartz-Bloom, R Sah
Mar 20, 2002·Neuroscience Research·Norio AkaikeTakayoshi Imazawa
Oct 31, 2015·International Journal of Molecular Sciences·Gratianne RabillerJialing Liu
Mar 4, 2008·Neuropharmacology·Kresimir Krnjević
Jun 20, 2012·The Journal of Physiology·Jesús Q Beltrán, Rafael Gutiérrez

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