GAP43 and Parkinson disease: We found that the expression of SNAP25 and SNAP91 were most significant in the HIP in AD mice, while SNAP25 and GAP43 in the SN with PD mice (AD: PSNAP25 = 4.11E−03, PGAP43 = 2.18E−13; PD: PSNAP25 = 0.017, PSNAP91 = 0.031).