Q‐ and L‐type calcium channels control the development of calbindin phenotype in hippocampal pyramidal neurons in vitro

摘要: Cultured immature hippocampal neurons from embryonic 17-day-old rats were used to explore activity-dependent regulation of neuronal phenotype differentiation in the developing hippocampus. The calbindin-D28k pyramidal appeared during first 6 days culture, and was expressed by 12% cells on day 6. Daily stimulation with 50 mM KCl 5 vitro increased number calbindin-D28k-positive without affecting survival. This effect prevented buffering extracellular Ca2+. Omega-agatoxin-IVA-sensitive Q-type nitrendipine-sensitive L-type voltage-gated Ca2+ channels (VGCCs) carried currents influx at somata level. Blockade these inhibited induced KCl. Conversely, glutamate-activated channel antagonists did not affect KCl-induced phenotype. Chronic blockade Q- and/or VGCCs downregulated normal development survival, somatic area or GABAergic-positive (gamma-aminobutyric acid) interneurons. However, later developmental stages, lost their ability control level, both failed regulate These results suggest that channels, which have been predominantly associated neurotransmitter release adult brain, transiently act synergy direct early before establishment synaptic circuits.