Histone acetylation has been shown to be involved in modulating the saliency of many environmental stimuli. Conditions which increase levels of histone acetylation appear to sensitize mice to cocaine, stress, pain, etc. while conditions that reduce histone acetylation diminish sensitivity to these stimuli. This has important implications in the pathogenesis of drug addiction, depression, chronic pain, and memory disorders. Ultimately, the key function of histone acetylation is to increase the transcription or the transcriptional potential of genes which eventually alter neural function [53]. Thus, any study of chromatin modifications is, in theory, inexorably linked with the study of the underlying gene activity, and may reveal novel signaling pathways not previously identified from studies of steady-state mRNA and protein levels. Regulation of chromatin structure also offers a fundamentally new approach for the development of more effective treatments for drug addiction and other neuropsychiatric disorders.
