Fig. 5

GPR37 mRNA expression and ecto-GPR37 levels in AD. GPR37 mRNA expression in post-mortem frontal cortex (a) and entorhinal cortex (b) from NCs (panel a: n = 17; b: n = 5), Braak AD stage 3/4 (a: n = 9; b: n = 4) and Braak AD stage 5/6 (a: n = 20; b: n = 5) subjects was assessed by RT-qPCR. Mean values of the housekeeping genes (GUS-B, XPNPEP1, AARS and HPRT) were used to normalize samples. Results are expressed as fold-change (mean ± SEM) of the NCs. c Detection of ecto-GPR37 in the CSF from NC (n = 22) and AD (n = 23) participants  recruited at the University Medical School of Göttingen. d ROC curve analysis of CSF ecto-GPR37