Fig. 2

Quantitative distribution of [¹⁸F]FPEB in different brain areas in the base mouse and ALS mouse at the stages 1 and 3. Comparison of the binding of [¹⁸F]FPEB in the striatum, hippocampus, cortex, and whole brain in base mice and ALS mice at the stages 1 and 3. It can be seen that mGluR5 expression is highly increased in ALS mice carrying SOD1-G93A gene compared to base mice and it is further increased when the disease progressed. Of the individual brain areas, the hippocampus has the highest increase between the base mice and ALS mice and further the highest increase between stages 1 and 3 making the hippocampus area the most sensitive brain area for glutamatergic modulation in ALS-type degeneration. Values for binding potential (ND) were calculated based on reference tissue model using cerebellar data as an input function [27, 33, 34]. Mean values for binding potential were calculated from four base mice and four ALS mice. Statistical analysis was done with student’s t test, and significances are marked to the figure (*p < 0.05 = , **p < 0.01 = , and ***p < 0.001 = )