Fig. 4.

Memantine prevents radiation-induced synaptic alterations. (A) Representative staining for presynaptic (VGLUT1)- and postsynaptic (PSD-95) markers and co-localization reconstructed from confocal stacks as a function of indicated time, sham vs radiation (RT), and drug treatment. (B) Analysis of VGLUT1/PSD-95 co-localization reveals that memantine prevented the previously identified increase in synaptic density at 1 h after RT. Presynaptic terminals, identified by VGLUT1 staining, demonstrated an increase in spot density (C) and volume (D) after RT or memantine alone. (E, F) Memantine had a strong protective effect on postsynaptic densities at 24 h but had more complex effects at shorter time points (see text for details). Data are shown as means ± SEM (n = 30–50 total neurons per condition per time point from 5 different animal preparations). *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001. Bar is 5 µm.