As covered in Nature Neuroscience magazine, a team led by Olivier George, assistant professor at The Scripps Research Institute in San Diego announced the results of their research titled “VTA CRF neurons mediate the aversive effects of nicotine withdrawal and promote intake escalation.” The team says they think these same neurons may be active in response to other addictive substances.
"If we can find a way to target those neurons in humans, maybe we can reduce the 'high' produced by the drug and reduce the withdrawal symptoms."
The team hold out hopes that their findings will lead to the development of drugs or gene therapies that can target the neurons and aid in addiction quit attempts.
Previously, the region of the brain they were looking at had only been associated with the pleasure/reward aspect of addiction and not the stress/withdrawal system. Further investigation was triggered when Olivier discovered a protein in that region strongly associated with anxiety and depression.
Using radioactive markers, the team observed the region in rat brain samples and eventually discovered the tell tale black dots on X-ray scans in the ventral tegmental area (VTA) - an area of the brain where the neurons are found.
"If you look in a textbook, these neurons don't exist in the VTA. That was the most exciting day of my career."
The research was expanded to cover mice and rat brains. The rodents had been developed to have nicotine dependence similar to a human using 40 cigarettes per day.
“Results revealed that the neurons in the VTA were activated during withdrawal, and upon examining brain samples from humans, the team found that these same VTA neurons are present.”
Results from previous studies into rodent and human failed quit attempts have shown that both will return to consuming more nicotine than used originally. Researchers looked to see if this was linked to the neuron activity in this region of the brain.
The team found that rodents with fewer of these neurons did not increase their nicotine uptake.