The Impact of Environmental Factors on 5-Hydroxymethylcytosine in the Brain

The aims of this review are to evaluate the methods used to measure 5-hydroxymethylcytosine (5-hmC), and then summarize the available data investigating the impact of environmental factors on 5-hydroxymethylcytosine (5-hmC) in the brain.

Recent research has shown that some environmental factors, including exposure to exogenous chemicals, stress, altered diet, and exercise, are all associated with 5-hmC variation in the brain. However, due to a lack of specificity in the methods used to generate a majority of the available data, it cannot be determined whether environment-induced changes in 5-hmC occur in specific biological pathways. Environment appears to shape 5-hmC levels in the brain, but the available literature is hampered by limitations in measurement methods. The field of neuroepigenetics needs to adopt new tools to increase the specificity of its data and enhance biological interpretation of exposure-related changes in 5-hmC. This will help improve understanding of the potential roles for environmental factors and 5-hmC in neurological disease.