SST and Alzheimer disease: They conclude their manuscript stating that: “while altered BDNF expression may not represent the primary disturbance in AD, changed expression of, or altered responsiveness to BDNF (and subsequently decreased SST levels) may represent a critical feature of Alzheimer's disease progression.” VSNL1 (Visinin-like protein 1) [565], a CA++ sensor protein is also down-regulated (see Figure 19), a finding which is paralleled in the work of Youn et al.[566], who found similar changes in hippocampus.