SLC17A7 and amyotrophic lateral sclerosis: In addition, the irreversible Piezo2 channelopathy theory of ALS posits that not only proton-based signaling to motor neurons is impaired through VGLUT1, but ultrafast proton-based long-range signaling to the hippocampus is also impaired through VGLUT2 (Figure 1) [8,18].