Poly dl ornithine coated coverslips

Standard dissociated hippocampal neuronal cultures were prepared from embryonic day 17 (E17) mice as described previously (Banker and Goslin, 1998) with small modifications. Briefly, hippocampal cells were dissociated by enzymatic treatment (0.25 % trypsin for 15 min at 37 °C) and plated (50,000 cells/cm 2 ) on poly-DL-ornithine-coated coverslips (Sigma, St. Louis, MO). The cells were grown in Neurobasal medium containing B27 supplement (Invitrogen, Carlsbad, CA) preincubated on astroglial cultures for 24 h. Standard dissociated cortical cultures were prepared from embryonic day 18 (E18) rats similar to the protocol described above for the hippocampal neuronal cultures. Neurons were plated (100,000 cells/cm 2 ) on poly-DL-ornithine-coated coverslips (Sigma, St. Louis, MO) and were grown in Neurobasal medium containing B27 supplement, glutamine, and penicillin + streptomycin antibiotics mix (Neurobasal medium and all additives were from Invitrogen/Gibco, Carlsbad, CA).