New insights into teenage brain functions have provide a new lead on why adolescents are more addicted to cocaine.

Study results published in the recent issue of the Journal of Neuroscience explain the increase in addiction incidences in adults who succumb to cocaine in their teenage years.

This study is seen as a precursor for developing advance research techniques to find gene regulators that protect the brain from effects of cocaine and other substance abuse.

Through a set of two new studies, Yale researchers observed when an adolescent brain is exposed to cocaine, the tendency of the brain is to build up defense reactions to minimize the impact of cocaine.

Researchers have shown that cocaine risk is much higher in adolescence, when the brain is shifting from an explosive and plastic growth phase to more settled and refined neural connections characteristic of adults, the study observed.

The new research on animal models has helped Yale scientists to identify key genes that control the brain's first defensive mechanism to cocaine. The research noted that any interference with the brain's initial defensive response to cocaine increased a mouse's sensitivity to cocaine.

Studies by Yale scientists in the past have also explained that brain cells or neurons and their synaptic connections in adolescence change shape when exposed to cocaine initially. This occurs via a molecular pathway that is regulated by integrin beta1, a crucial gene in the development of the nervous system in vertebrates.

This suggests that these structural changes observed are probably protective of the neurocircuitry, an effort of the neuron to protect itself when first exposed to cocaine, added Koleske.

In the latest study, the researchers reported that when they did away with the integrin beta1 regulated pathway, mice needed approximately three times less cocaine to induce behavioral changes than mice with an intact pathway. 

Lead author Anthony Koleske writes: The research suggests that the relative strength of the integrin beta1 pathway among individuals may explain why some cocaine users end up addicted to the drug while others escape its worst effects. If you were to become totally desensitized to cocaine, there is no reason to seek the drug.