Our genes and environment work together to influence brain development throughout a lifetime, new studies have revealed.
The studies examine how such environmental information can be transmitted from one generation to the next - a phenomenon known as epigenetics.
This new knowledge could ultimately improve understanding of brain plasticity, the cognitive benefits of motherhood, and how a parent's exposure to drugs, alcohol, and stress can alter brain development and behaviour in their offspring.
Brain cell activation changes a protein involved in turning genes on and off, suggesting the protein may play a role in brain plasticity.
Prenatal exposure to amphetamines and alcohol produces abnormal numbers of chromosomes in fetal mouse brains.
The findings suggested these abnormal counts might contribute to the developmental defects seen in children exposed to drugs and alcohol in utero.
Cocaine-induced changes in the brain may be inheritable. Sons of male rats exposed to cocaine are resistant to the rewarding effects of the drug.
Mice conceived through breeding - but not those conceived through reproductive technologies - showed anxiety-like and depressive-like behaviours similar to their fathers.
The findings call into question how these behaviours are transmitted across generations.
"Research in the last few years has dramatically changed what we know about how behaviours are inherited," said Flora Vaccarino, MD, from Yale University, an expert on the developing brain.
"Today's findings show how our genes and environment work together to influence brain development throughout a lifetime," Vaccarino added.
The findings were presented at Neuroscience 2011, the annual meeting of the Society for Neuroscience.