Fig. 3.

BDNF-induced Arc transcription requires intracellular, but not extracellular calcium. Cortical neurons were stimulated by 5ng/ml BDNF (A) or KCl (50mM) (B) for 1hr, after which total RNA was extracted and used for semi-quantitative RT-PCR. Extracellular calcium chelator (EGTA, 2.5mM), and intracellular calcium chelator (BAPTA-AM, 33uM) were applied 30min before BDNF and KCl stimulation. The levels of Arc and GAPDH mRNA were determined by RT-PCR using gene specific primers. Representative images are shown in the left panels, and quantification in the right panels. The relative intensity of Arc was normalized to GAPDH.