section_path: Genetics/Epigenetics
section_name: Epigenetics
paragraph_text: Epigenetics
  
  Studies of the molecular basis for memory formation indicate that epigenetic mechanisms operating in neurons in the brain play a central role in determining this capability. Key epigenetic mechanisms involved in memory include the methylation and demethylation of neuronal DNA, as well as modifications of histone proteins including methylations, acetylations and deacetylations.
  
  Stimulation of brain activity in memory formation is often accompanied by the generation of damage in neuronal DNA that is followed by repair associated with persistent epigenetic alterations. In particular the DNA repair processes of non-homologous end joining and base excision repair are employed in memory formation.