The study, led by Mathieu Wimmer, in the laboratory of R. Christopher Pierce from the Perelman School of Medicine at the University of Pennsylvania, found that sons, but not females, of male rats on cocaine were not only less likely to want the drug, but also resistant to effects of it.
This suggests cocaine causes epigenetic changes- that is alterations to DNA that do not involve changing the sequence- in sperm in which reprogrammed information is transmitted down to the next generation of men.
The authors focused on the physiology of neurons before and after taking cocaine in the offspring of cocaine-experienced fathers, and found that they were less sensitive to the drug and less likely to succumb to addictive behaviours.
In short, not only are rat offspring of cocaine-abusing fathers less likely to take the drug on their own volition, they are less likely to become addicted to it if they are administered it.
In male rats whose fathers used cocaine, the neurons in the nucleus accumbens were less sensitive to cocaine. That is, repeated cocaine use in the sons of cocaine-experienced fathers did not cause remodeling of excitatory AMPA receptors, which is thought to be critical for the development of addiction and cocaine craving.
The study was presented at Neuroscience 2013.