Learning a lesson
“Motivational conflict is another critical component of human addiction, and we can also include that in our lab tests,” De Vries adds. “Rats that learn that consuming addictive substances may or may not lead to a tiny electric shock from the grid that they walk on sometimes completely refrain from taking these substances.”
The reason why some rats stop taking addictive substances when they know it may have negative consequences, while others don’t, is a crucial question for De Vries. “By studying this principle in rats, we might also find out what makes one person more resilient to addiction than another.”
Does the insula hold the key?
De Vries looks for his answers in the brain’s many complex networks. “You’ll never find one single area or one single chemical in the brain that holds all the clues for addiction. The brain’s ‘reward system’ plays a crucial role, just as much as cognitive control or memory. Despite that complexity, we also know that one specific region – the anterior insula cortex – plays a relatively large role in addiction. Some people whose insula is damaged by a hemorrhage, for example, may be released from their smoking addiction from one day to the next. Therefore, we pay extra attention to this area in imaging and anatomical and physiological research.”
The insula also plays a role in new therapies that aim to cure addiction. “In Transcranial Magnetic Stimulation, large coils are used to direct magnetic fields into specific parts of the brain to modulate neuronal activity,” De Vries explains. “International colleagues have already had some success in using Transcranial Magnetic Stimulation aimed at the insula to treat heavy smokers. Together with brain network specialists Menno Schoonheim and Linda Douw, we are going to study whether the insula indeed represents a critical hub in resilience to addiction.”