Aim: To observe the change of potassium current on cultured neurons differentiated from hippocampus neural stem cells of the newborn rat.
Methods: Neural stem cells from newborn rat hippocampus were cultured in vitro and passaged continuously. Differentiation of the cell was induced by serum and removing mitogens. After differentiation cells were plated on plastic dishes and cultured for 1 d, 7 d, 14 d and 21 d. Whole-cell voltage patch clamp recording was used respectively to detect voltage-dependent K+ current.
Results: After 1 d culture, no current was detected, and on the 7th d, 14th d, 21st d after differentiation, the amplitude of K+ currents was (18.077 +/- 2.789)pA/pF, (13.099 +/- 2.742)pA/pF, (34.045 +/- 8.067)pA/pF at +50 mV. The recorded K+ current included two components that could be blocked by TEA and 4-AP separately, assumed the slowly inactivating delayed rectifier K+ current (IK) and the fast inactivating transient outward K+ current (IA).
Conclusion: The function of potassium channels on the hippocampus neural stem cells of the newborn rat approaches mature gradually when the time of differentiation becomes longer in vitro.