Primary neuronal cultures
Cortices and hippocampi were isolated on embryonic day 16 (E16.5) rinsed and dissected in ice-cold PBS and incubated with 0.25 % trypsin for 25 min at 37 °C. The digestion was terminated by the addition of DMEM solution supplemented with 10 % FBS followed by trituration tissue dissociation. The resulting cells were centrifuged for 5 min at 800 rpm and neurons dissolved in Neurobasal medium supplemented with 2 % B-27, 0.5 mM L-glutamine and 1 % penicillin/streptomycin. The cells were plated at a density of 2x105 cells/well in 6-well poly-L-lysine-coated tissue culture dishes or on coverslips where necessary. Cells were cultured for 10 days (DIV10) for neuron maturation under 5 % CO2 at 37°C. Neuronal purity was >90 % as determined by immunofluorescence using the neuronal marker βIII-tubulin.