SYT1 and Cognitive impairment: Indeed, Chen et al. (2007), who categorized their animals with the MWM test and used only dorsal hippocampal tissue for western blotting analysis, reported that cognitive impairment correlated with increased SYT1 levels, whereas Nicolle et al. (1999), who categorized the animals by the same test but examined the whole hippocampus found no difference in SYT1 levels.