NRGN and Cognitive impairment: This may be related to the excessive breakdown of neurogranin in exosomes and brain tissue into disulfide bridge or glutathione modified peptides and their release into the cerebrospinal fluid.[58] This is the exact opposite of the changes in the cerebrospinal fluid, where neurogranin in the blood neurogenic exosomes has changed even 5 to 7 years before the onset of cognitive impairment.[59] It may be more sensitive to the diagnosis of AD at the stage of mild cognitive impairment.