DPM, but not PAM, is neurotoxic to neuron/microglia co-cultures. Cortical neurons were cultured alone or with PAM or DPM for 24 h. A. The cells were loaded with calcein-AM. The results are shown in representative fluorescence images (a, c, e) and phase contrast images (b, d, f). B. Neuronal process integrity was verified with immunostaining for MAP-2 and tau in cortical neurons alone (a-c) or co-cultured with PAM (d-f) or DPM (g-i).