CHGA and dementia: In contrast, the concentrations of NrCAM, a synaptic adhesion molecule [19], [46]–[49], chromogranin A, a dense core synaptic vesicle protein [19], [20], [22], [59]–[62], and carnosinase I, a neuronal dipeptidase responsible for degradation of the anti-oxidant and metal-chelating dipeptide carnosine [33], [107]–[111] do not decline until mild dementia ensues (CDR 1).