Our experiences may impact the genes that influence our behaviour and health, new research has shown.
The research provides new insights into how experience
might produce long-term brain changes in behaviours like drug addiction and memory formation.
The studies, presented at Neuroscience 2013 in US, the annual meeting of the Society for Neuroscience, focused on an area of research called epigenetics, in which the environment and experiences can turn genes "on" or "off," while keeping underlying DNA intact.
These changes affect normal brain processes, such as development or memory, and abnormal brain processes, such as depression, drug dependence, and other psychiatric disease - and can pass down to subsequent generations.
According to one study, long-term heroin abusers show differences in small chemical modifications of their DNA and the histone proteins attached to it, compared to non-abusers.
These differences could account for some of the changes in DNA/histone structures that develop during addiction, suggesting a potential biological difference driving long-term abuse versus overdose.
Another study found that male rats exposed to cocaine may pass epigenetic changes on to their male offspring, thereby altering the next generation's response to the drug.
Researchers found that male offspring in particular responded much less to the drug's influence.
A third study found that drug addiction can remodel mouse DNA and chromosomal material in predictable ways, leaving "signatures," or signs of the remodelling, over time. A better
understanding of these signatures could be used to diagnose drug addiction in humans.