Extraction, Identification, and Quantification of Histones from Small Quantities of Specific Brain Tissue.

Histone posttranslational modifications (PTMs), by their action on the chromatin state, play a central role in the regulation of gene expression. The discovery that some PTMs in the brain are dynamically regulated by experience and environmental factors makes them an important subject for the study of plasticity changes in learning and memory, addiction, and psychiatric disorders. Current histone isolation protocols, however, require large amounts of tissue, which limits their application for analyzing small tissue samples from a specific brain region. We describe here a step-by-step protocol for histone extraction and isolation from 1 mm(3) of tissue from brain punches, which allows reproducible and reliable results for histone PTM identification and quantification without losing anatomical precision. © 2016 by John Wiley & Sons, Inc.