Effects of Nicotine on the Brain

There is no disputing nicotine is addictive, but researchers are just now beginning to understand the effects of nicotine on the brain. Just in the last decade scientists have begun finding answers. Let’s follow the path of nicotine through the human body and see what some researchers have discovered:

Hitching a Ride

Nicotine rides on the back of tar, entering the lungs and into the bloodstream. If the tobacco is chewed, then the nicotine, as well as other chemicals, is absorbed through the mucous membrane. Nicotine replacement products administer the nicotine through the skin, through the nasal membranes or also through the mucous membranes.

Slipping through the Cracks

There exists a semi-permeable membrane called “The Blood-Brain Barrier.” This protection keeps out unwanted bacteria and other pathogens, while allowing oxygen and other smaller molecules. Unfortunately the nicotine molecule is also small enough to pass through this barrier. About 8 seconds after taking your first hit, nicotine is through and affecting your brain’s chemistry.

The Imposter

In the brain, billions of nerve cells are communicating with chemical molecules called “neurotransmitters.” These molecules are like keys that fit into receptor “locks” in the brain. Nicotine mimics the “key” called acetylcholine. Acetylcholine is meant to fit into the receptor for dopamine, but nicotine hijacks it’s place and instead floods the dopamine receptors.

Changing the Way We Think

Dopamine is responsible for feelings of pleasure in the brain, and with the flood of acetylcholine like imposters, namely the nicotine, the pleasure centers of the brain become saturated. Especially in those with brain tissue still developing, the brain’s dopamine pathways are altered to account for this flood of nicotine. Now the brain literally needs the nicotine to function properly.

Although research has lead to the developments of medications have been developed to intercept nicotine’s path to the brain’s dopamine receptors, many have deadly side effects. If you need help quitting, talk to your doctor and develop a plan that addresses the social, emotional and physical reasons you smoke. Don’t give up on the first try; sometimes it takes many attempts to quit smoking. Keep at it and soon you may find yourself breaking the habit for good.

Resources:
http://teens.drugabuse.gov/mom/mom_nic2.php
http://faculty.washington.edu/chudler/nic.html

Photo: Wikimedia. No endorsement implied. For license information, visit http://commons.wikimedia.org/wiki/File:Nicotine.qutemol.png.

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