Variable Details

Available Studies



Not Scaled

Variable Type 


Variable Name 



Brain Proteins

Synaptosomal-associated protein 25 (SNAP-25) density - Average of 6 regions (MAP only)

This variable is only available in MAP.

Synaptosomal-associated protein 25 (SNAP-25) density is determined by immunoassay in the Honer Lab at the University of British Columbia (Vancouver BC, Canada). SP12 antibody is used to quantify SNAP-25 immunodensities from frozen samples of gray matter in 6 cortical regions:

  1. Hippocampus
  2. Middle frontal gyrus
  3. Inferior temporal gyrus
  4. Calcarine (visual) cortex
  5. Ventromeidal caudate
  6. Posterior putamen

Values are expressed in log10 units, the mean is determined for each participant across the 6 regions, and a z-score is calculated across all participants. Since reported values are inversely proportional to protein levels, scores are multiplied by negative 1 to make results directly related to the amount of target antigen. Higher values indicate greater SNAP-25 protein concentrations.