Fig. 3. Concentration–response curves for steady state NMDA-gated currents from cortical neurons cultured for 1–4 weeks. The response to each concentration of NMDA for each cell has been normalized to the maximum response by that neuron. Note the curves either reach the plateaus (week 1 and 2) or the peaks (week 3 and 4) at 100 μm NMDA. The n is 4 for 1 week, 5 for 2 and 4 weeks, and 6 for 3 weeks.