Introduction to Nicotine

What is it?

Because it is an insecticide, it is a deadly poison. Drop for drop it is more lethal than strychnine or rattlesnake venom and 3X more lethal than arsenic. But, fortunately, most of the toxins are burnt up in tobacco smoke so what is inhaled is a fraction of the amount found in tobacco.

The toxins that do enter the body, while not immediately lethal, over the long term cause all the health problems we are familiar with.

The amount that is absorbed depends on:

• the type of tobacco
• whether or not the person inhales and
• if the cigarette is filtered or not.

How it Works in the Brain

To understand how nicotine works it is necessary to first understand a little of how the brain works.

The brain is able to process, store, and use information due to the action of the neurons in the brain. The cells in the brain that are responsible for the transfer and integration of information are called neurons.

When signals are received in the brain they are conducted along each neuron as an electrical current. But, in order to pass the signal along to another neuron a chemical messenger called a neurotransmitter is needed. Neurotransmitters transmit the message across the gap between neurons. Each neurotransmitter has its own special receptor site on the adjacent neuron and the amount of neurotransmitters is regulated by the body.

The Effects of Nicotine on Some of the Neurotransmitters

The effects of nicotine on some of the neurotransmitters include:

1. Increases the release of acetylcholine which has as one of its functions the ability to increase energy levels.

   Smokers, therefore, use cigarettes to re-energize throughout the day and thereby improve their reaction time and the ability to pay attention. They get the feeling that they can do their work more efficiently.

2. Promotes the release of dopamine in the reward pathways of the brain. Dopamine was intended as a survival mechanism because it positively reinforces the behaviors necessary for survival – like eating when hungry.

   While no longer needed for survival, when dopamine is released by nicotine, it causes those same reward pathways to be activated. As a result the smoker associates the good feelings, caused by the dopamine, with smoking.

   Because the half-life of nicotine is only 1 to 2 hours, in order for the feelings of peace and happiness to continue the smoker must continue to smoke.

3. Release of glutamate which is responsible for learning and memory. When present, glutamate enhances the connections between the neurons and these stronger connections are believed to be the basis for what we call memory.

   So glutamate is responsible for creating the memory of the good feelings caused by smoking and therefore it further drives the desire to smoke again.

4. Endorphins are also released when smoking. Endorphins are small proteins, similar to morphine and are responsible for alleviating pain in the body. They also cause a feeling of euphoria like the rush one gets after running or exercise.

   So although the purpose of endorphins is different from that of dopamine, the result is the same, i.e. the smoker wants to continue smoking because of the positive feelings derived.