Teenage Mice More Sensitive to Drugs
Finding May Explain Higher Addiction Tendency in Human Adolescents
Nov. 1, 2002 -- Teen brains appear more sensitive to drug abuse than adult or child brains. The finding, in adolescent mice, may help explain why teenagers are particularly susceptible to addiction.
Michelle E. Ehrlich, MD, and colleagues at Thomas Jefferson University in Philadelphia already knew that a brain protein called DeltaFosB is linked to reward. Naturally rewarding activities such as running on a treadmill or drug-induced pleasures such as cocaine use increase the amount of DeltaFosB in the rodent brain.
The teen years are marked by huge changes in the brain. Ehrlich's team noted that drugs of abuse are particularly addictive for teens. They checked DeltaFosB levels in the brains of child, adolescent, and adult mice after giving them seven days of cocaine or amphetamines. Sure enough, DeltaFosB levels shot up much higher in mouse adolescents than in younger or older animals.
"An increase in this protein may be important because it could also affect other molecules that could lead to long-lasting changes in the brain in response to psychostimulant drugs," Ehrlich says in a news release.
Interestingly, DeltaFosB accumulated in areas of the brain linked to hyperactivity and attention deficit syndrome. Only the teen mice had DeltaFosB buildup in this area as well as in brain areas linked to reward.
Ehrlich's team is studying the specific brain patterns affected by DeltaFosB. They hope to come up with a better animal model for studying addiction. They also hope to find out whether drugs aimed at DeltaFosB interactions might be useful in treating addiction.
The findings appear in the November 1 issue of the Journal of Neuroscience.