Figure 6
Evaluation of synaptotoxicity and potential synaptogenesis. The effects of several small molecule compounds on pre- and post- synaptic puncta were tested, n = 3 per group at each concentration with five images per well. (a) Time series analysis of synaptotoxic effect from different concentrations of glutamate over 72 hours. Glutamate significantly decreased the number of colocalized puncta after 24 hours in a dose-dependent fashion; at high concentrations (≥25 µM), glutamate significantly reduced the number of colocalized puncta over time (more than 80% lost, ****p ≤ 0.0001, one way ANOVA with Dunnett’s multiple comparisons test, treated vs NTC), the effect was decreased at low concentrations (~50 to 70% lost at 2.5 µM and less than 30% lost at 250 and 25 nM, **p ≤ 0.01, *p ≤ 0.05), and showed minimal to no lost at very low concentration (2.5 nM) (also see Supplementary Fig. 7 for example images and Supplementary Figure 8 for changes at presynaptic and postsynaptic terminals). (b) Neuron viability test using MTT assay after 72 hours incubation with glutamate. Significant loss of neurons was identified at high concentrations of glutamate (2.5 mM and 250 µM, ****p ≤ 0.0001), mild to minimal cell death were identified at lower concentrations (****p ≤ 0.0001, **p ≤ 0.01). (c) BSA had no effect at any tested concentration after 24 hours; (d) 1x Pen Strep had no effect on pre-, post- and colocalized synaptic puncta after 24 hours.
