How Does Nicotine Affect Cells?

Around 18 billion cigarettes are sold per day around the world, with an estimated one billion smokers. Whilst cigarettes are known to cause smoking-related diseases such as cancer, heart attack and respiratory tract infections, little is known about the effects of tobacco and nicotine on the cells of smokers.

So, what is the wider effect of the addictive drug nicotine? Scientists at the California Institute of Technology have developed new sensors to find out just that. By shining a light on the movement of nicotine, they can discover how nicotine truly affects cells from the inside out.

Protein sensors for nicotine

Endoplasmic reticulum is a network within cells, where proteins are synthesized before being sent to places inside and outside the cell. Nicotinic receptors (nAChRs) are found within these proteins. So, when someone smokes a cigarette, nicotine flows into the brain and latches onto nAChRs on these cells. This results in feelings of happiness and reward.

Although it’s common knowledge that nicotine is an addictive substance, there is less understanding about what happens when nicotine has moved into - rather than onto - the cells.

To understand this process a recent study developed a protein sensor that glows when nicotine is present. This allows them to detect the movement of nicotine - showing where the molecules are located and how many there are.

How nicotine fuels addiction

With the sensor, the scientists discovered that nicotine entered the endoplasmic reticulum within seconds and accompanied the nAChRs to the cell surface. This leads the neurons to become more sensitive to nicotine.

This research led them to discover that repeated exposure meant heightened sensitivity to nicotine, only reinforcing the effects of reward and the overall dependency. Simply put, the more cigarettes you smoke, the quicker you will feel the effects of nicotine, only fuelling the addiction.

Effects on the brain

That’s not only effect of tobacco, with other research highlighting that nicotine increases the risk of cognitive impairment, particularly in adolescent smokers. This can affect the areas of the brain that are responsible for attention, memory and learning.

Nicotine isn’t the only substance which has adverse effects on the brain, with other addictive and non-addictive drugs having complex reactions. For example, recent studies highlight that LSD feeds off your imagination causing hallucinogenic effects. This is due to the drug LSD causing the thalamus in the brain to stop processing and filtering information.

Researchers are now looking to develop biosensors to understand the wider effects of substances on the brain and the body – and how other they interact with cells. To find out more about the identification and effects of unknown substances more broadly, take a look at the article ‘Characterising Unknowns: Behind the Scenes of Chemical Investigation’.