plot the differences that were seen in dna methylation, histone acetylation (mark of open chromatin = permissive for gene transcription) and rna expression; can see the correspondence between these 3 things. Looked at human brain samples the same way that we looked at rat brain samples. pro-inflammatory cytokines: these cytokines can be pro/anti/both depending on the context y cytokines role in depression, major depression = frequently associated with changes in immune signaling; ppl with. Mdd tend to have chronic inflammation; also known that ppl who have disorders that affect immune fxn (ms, rheumatoid arthritis = associated w/ inflammation) tend to have more major depression than the general population. but it s not surprising that ppl with major health problems have mdd; makes it hard to know whether causal or just associated: other evidence that shows that cytokines directly affect cognitive function and depressive symptoms.