CREB1 and Alzheimer disease: In the NAcc of AD mice, there was a significant increase in the phosphorylated levels of cyclic AMP-response element binding protein (CREB), a modest but statistically significant increase in ΔFosB protein levels, and a large but not statistically significant increase in brain-derived neurotrophic factor (BDNF) levels compared to the NOR group (Fig. 4A and Additional file 1: Fig. S3A).