Figure 5. Sigma2/PGRMC1 receptor is present in human neocortex and is upregulated in AD.

A. Control receptor expression (unrelated receptor sigma-1 labeled with [³H]pentazocine 1 nM) declines in advanced AD patient frontal cortex sections vs. age-matched cognitively normal individuals (N = 4, *p = 0.0375, Student's t-test). B, adjacent sections from the same individuals labeled with [¹²⁵I] sigma-2 antagonist RHM-4 (0.2 nM) reveal sigma-2 receptor expression is not significantly changed in the disease state vs. normal individuals (N = 4). TB  =  Total binding. NSB  =  non-specific binding in presence of 10 fold excess cold ligand. C, D, Quantified values for binding in images shown in A and B expressed as the percent of specific binding in controls.