The rats were allowed to absorb the nicotine for an hour a day for 42 days. They were then killed and their brains dissected.
Rodents that took the medium and higher doses suffered a 50% higher loss in the production of new brain cells than the non-nicotine group, as well as a significantly higher rate of brain cell death.
The researchers also found that all the rats taking nicotine suffered a fall in the protein PSA-NCAM.
This protein plays a vital part in the adaptibility of the brain and is related to an ability to learn and memorise.
This research findings rebutt previous research in the 1990s that suggested that smoking could boost cognitive performance.
