Characterization of dynorphin-containing neurons on dissociated dentate gyrus cell cultures

Further identification of NSF* as an epilepsy related gene

Previous data proved that NSF* was an epilepsy related gene (ERG1). In this study, using phosphorothioate oligodeoxynucleotide (PS-ODN), an antisense of NSF to downregulate the function of NSF in vitro cultured hippocampus neurons and PC12, this treatment simultaneously induced enhancement of the neurite outgrowth of hippocampal neurons and PC12, a phenomenon similar to the structural changes following epilepsy. Immunocytochemistry analysis showed that the enhancement of neurite outgrowth was in a sequence-specific manner and Northern blot confirmed that the decrease of NSF mRNA levels in PC12 was in a dose-dependent manner. Moreover the expression of NSF was downregulated during differentiation of PC12 induced by NGF and high KCl. Therefore, providing more evidence to support the fact that NSF was an ERG1.

Electrophysiological properties of neurones in cultures from postnatal rat dentate gyrus

Electrophysiological properties of neurofilament-positive neurones in dissociated cell cultures were prepared at postnatal days 4-5 from rat dentate gyrus and studied using the whole-cell patch-clamp technique. These cells expressed a fast-inactivating, 0.5 microM tetrodotoxin-sensitive Na+ current; a high-voltage-activated (HVA) Ca2+ current, which was 30 microM Cd(2+)- and partially 2 microM nicardipine-sensitive; and an inward rectifier current, which was sensitive to extracellularly applied 1 mM Cs+. The outward current pattern was composed of a delayed rectifier-like outward current sensitive to 20 mM tetraethylammonium (TEA) and a fast-inactivating, Ca(2+)-dependent outward current. This transient Ca(2+)-dependent K+ outward current was identified by a subtraction procedure. K+ currents recorded under conditions of blocked Ca2+ currents (after rundown of the HVA Ca2+ current or blocked by extracellularly applied Cd2+) were subtracted from control currents. By comparison with the current pattern of identified dentate granule cells, it is concluded that the investigated cell type originated from interneurones or projection neurones of the dentate hilus.