[Genome] Questions on gene expression data

[William Grisham]

Hi,

I am teaching an undergraduate neuroscience class and using the UCSC 
Genome Browser as a tool in instruction.

We are interested in the expression data.  I took a class from Open 
Helix a couple of years ago and was led to believe that if the box for 
a given tissue was red, the gene was upregulated.  If the box is green, 
it is downregulated.

My question is up or down regulated relative to what?

Many thanks for the UCSC Genome Browser--it has been a terrific 
teaching tool!

Sincerely,

William Grisham, Ph.D.
Department of Psychology
UCLA
1285 Franz Hall
P.O. Box 951563
Los Angeles, CA 90095-1563

grisham at lifesci.ucla.edu
(310) 825-7990