Interactive report High-threshold calcium channel activity in rat hippocampal neurones during hypoxia 1

AbstractWhole-cell patch clamp recordings in combination with direct control and measurements of O tension.pO in bath solution were 22 used to determine the sensitivity of Ca 2q channels of cultured hippocampal neurones to hypoxia in glucose free solution. In all testedneurones, a lowering of pOto4 2 %50 mmHg did not induce changes either in magnitude, kinetics or voltage-current relations of totalCa currents, which composed mainly from two types, L-type 64% and N-type 31% components. Hypoxia only induced a delay of2 q . .Ca 2q current run-down about 27.5% and 39% at 50 and 4 mmHg pO respectively that presumably depended on changes in cytoplasmic 2 channel-modulatory metabolites. The obtained results demonstrate that Ca 2q channel molecules in cultured hippocampal neurones arethemselves insensitive to short-lasting 10–20 min oxygen and glucose deprivation, and that they are not a principal target for hypoxic.influences on hippocampal function. q1999 Elsevier Science B.V. All rights reserved.