If a father uses cocaine it could set up his son to be less susceptible and less likely to get addicted to the drug.

Researchers found that sons (but not daughters) of male rats that were addicted to cocaine were less likely to want the drug and did not feel its effects as strongly, a University of Pennsylvania School of Medicine news release reported.

The findings suggest that cocaine triggers "epigenetic changes," which are changes in DNA that do not interfere with its sequence. The changes are believed to occur in the sperm, which then transfers the changes to the rat's offspring.

The team found that the phenomenon could most likely be attributed to the brain-derived neurotrophic factor (BDNF), which is a molecule that is partially responsible for the pleasure associated with cocaine use.

The team looked at the neuron physiology in the offspring of rats that had been addicted to cocaine. They observed the functions both before and after the second generation had tried the drug. The researchers concluded the rats were less susceptible to the drug because their nucleus accumbens were less sensitive to cocaine than they would be in a rat with a "clean" father.

This means the rats' fathers' cocaine use did not remodel the excitatory AMPA receptors, which should be a crucial factor in cocaine craving.  

"This adds to the growing body of evidence that cocaine abuse in a father rat can affect how his sons may respond to the drug-and point to potential mechanisms that contribute to this phenomenon," Mathieu Wimmer, PhD, a post-doctoral researcher in the laboratory of R. Christopher Pierce, PhD, associate professor of Neuroscience in Psychiatry at the Perelman School of Medicine at the University of Pennsylvania said. "Further research is needed to better understand how these behavior changes are passed down from one animal generation to the next, and eventually if the same holds true for humans."