Voltage- and gamma-aminobutyric acid-activated membrane currents in the human medulloblastoma cell line MHH-MED-3

The whole-cell patch clamp technique was used to characterize voltage- and neurotransmitter-activated currents in the medulloblastoma cell line MHH-ME D-3 and cells from tissue slices and primary cultures of two medulloblastom a biopsies. These preparations revealed similar electrophysiological proper ties. All tested cells displayed 4-aminopyridine-sensitive delayed rectifyi ng K+ currents, gamma-aminobutyric acid(A) receptor-mediated Cl- currents a nd most of them inward rectifier K+ currents. Transient inward currents wer e mainly carried by low-voltage activated T-type Ca2+ channels in MHH-MED-3 cells, and tetrodotoxin-sensitive Na+ channels in cells from the primary c ulture. From these characteristics we conclude that medulloblastoma cells s hare physiological features with developing cerebellar granule cells at an immature stage. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.