Permanent and plastic epigenesis in neuroendocrine systems

• Epigenetics explains how environment or early-life events have lasting outcomes on overall health.
• Sexual differentiation of neuroendocrine systems is a useful neuroepigenetic model.
• Neuroepigenetic alterations may be stable or plastic across a lifespan.

The emerging area of neuroepigenetics has been linked to numerous mental health illnesses. Importantly, a large portion of what we know about early gene × environment interactions comes from examining epigenetic modifications of neuroendocrine systems. This review will highlight how neuroepigenetic mechanisms during brain development program lasting differences in neuroendocrine systems and how other neuroepigenetic processes remain plastic, even within the adult brain. As epigenetic mechanisms can either be stable or plastic, elucidating the mechanisms involved in reversing these processes could aid in understanding how to reverse pathological epigenetic programming.