title: [Electrophysiological properties of delayed rectifier outward K+ currents in the differentiation and development of hippocampal neural stem cells].
abstract: OBJECTIVE
  To study the developmental electrophysiological properties of delayed rectifier outward K+ currents (IDR) in undifferentiated NSC and NSC-derived neurons at various time points of adult SD rat hippocampus in vitro.
  
  
  METHODS
  Neural stem cells were isolated from the hippocampus of adult SD rats with serum-free incubation and single-cell cloning technique. Electrophysiological recordings of IDR were performed using whole-cell patch clamp.
  
  
  RESULTS
  The current density of IDR increased in NSC-derived neurons DIV 0-6 d whereas remained constant in DIV > 6 d. The current density of IDR at +50 mV was 45 pA/pF +/- 4 pA/pF and 56 pA/pF +/- 10 pA/pF in undifferentiated NSCs and NSC-derived neurons DIV 0-6 d respectively (n = 9). The activation process of IDR was also altered in DIV 0-6 d whereas remained constant in DIV > 6 d. The positive shift in steady-state activation curve of IDR revealed an increase of V1/2, however the slope factors K remained unchanged. V1/2 was 9 mV +/- 3 mV and 12 mV +/- 3 mV in undifferentiated NSCs and NSC-derived neurons DIV 0-6 d respectively (n = 9, P < 0.05). The inactivation properties of IDR were not altered before and after differentiation.
  
  
  CONCLUSIONS
  Electrophysiological characteristics of IDR were all altered in DIV 0-6 d, suggesting the essential role of IDR in neurogenesis and early stage of differentiation/development process is very important for the functional mature of neuron.
authors.affiliation: Department of Scientific Research, Zhu-Jiang Hospital, Southern Medical University, Guangzhou 510282, China.
authors.forename: Hong-bo
authors.initials: HB
authors.lastname: Guo
authors.forename: Fei
authors.initials: F
authors.lastname: Zou