Figure 7. Inhibition of NMDA receptors is sufficient to block glutamate-induced ER fission.

(A) Representative image of a dendrite from a neuron with normal dendritic and ER structure. (B) Treatment with 25 µM MK-801 for 10 min prior to 100 µM glutamate prevented ER fission although an effect on gross dendritic structure was seen (reduction in spine length). (C) After 24 h, 19 out of 20 cells had survived and resumed normal morphology. (D) Normalized average FRAP signal over time in untreated neurons (blue), the same neurons after MK-801 and glutamate for an average of 35 min (orange) and after 24 h (purple). Photobleaching was performed between the arrows. Time = 0 was set to when photobleaching ends and fluorescence starts to recover. Error bars are SEM. (E) Box plot of τ_eff values in untreated neurons (blue) and the same neurons after glutamate (orange). The line in the box is the median and the box represents the 25–75 percentiles. Whiskers extend to the extreme values as long as they are within a range of 1.5× box length. One neuron was outside this range and plotted as an outlier. Scale bars in all panels: 10 µm. avg.: average.