Recent years have witnessed an explosion of research on the role of epigenetic modifications, such as DNA methylation and histone protein acetylation and phosphorylation, in neuroscience. These changes exert control over gene expression and have been shown to play important roles in a variety of neural processes, including learning and memory. We and others have also recently shown that epigenetic changes may contribute to neurodegenerative disorders, such as Alzheimer's disease. Western blot analysis with antibodies raised against specific histone modifications is a relatively simple technique able to reveal the type, location, and degree of histone posttranslational modifications produced by an experimental manipulation. Here we provide a step-by-step protocol for isolating histone proteins from tissue and measuring these posttranslational modifications.