A new study has shown that the addictive drug in cigarettes, nicotine, tricks the brain into creating memories linking smoking with a feeling of wellbeing.
Pleasant events such as drinking alcohol, eating with friends or even driving home from work can then act as cues that make people want to have a cigarette. Smokers have often complained that they find it so hard to give up because certain aspects of their daily routine are strongly associated with smoking, so the study gives a clue as to how those associations come into being.
Dr John A Dani, who lead the study, is a professor of neuroscience at Houston’s Baylor College of Medicine. The results, which are published in this month’s edition of the journal Neuron, was gathered after mice were fed nicotine and their subsequent brain activity recorded.
The mice were allowed to roam through a space with two compartments. In one they received nicotine while in the other there was a saline solution. The scientists recorded how long they spent in each compartment and was their brain activity was in each one.
They discovered that nicotine strengthened neuronal connections by up to 200%. The connections underlie how new memories are formed.
Dr. Dani said that when we act in a way that contributes to our well-being, the brain sends out a reward signal. The nicotine “commandeers” this process so we begin to act as though smoking is a positive action.
He suggested that the discovery could have an impact on how we understand memory and might lead to the development of a treatment for memory disorders, such as Alzheimers.