Smoking Causes Chemical Dependency to Nicotine.
When you smoke, nicotine enters the blood stream and reaches the brain within ten to twenty seconds. Nicotine then binds to neural receptors and activates neural activity in the brain. (Neurons become active and pass on messages that will activate other neurons.)
The neurons triggered by nicotine are all connected to larger neural networks, such as those contained within the primal area of the brain known as the Basal Ganglia. One such network of neurons within the Basal Ganglia is of particular importance when it comes to understanding nicotine addiction, the human brain’s motivational reward system.
Once triggered into action, the reward center releases into the brain, the chemical dopamine. A chemical that causes us to feel pleasure and satisfaction. The reward center of the brain influences our behaviors and is typically called into action whenever we perform basic survival functions like eating, drinking or having sex.
Each time nicotine is received, the brain’s reward center is activated and the behavior of smoking is again reinforced as being a positive experience. After a few cigarettes, stronger neural pathways which expect the delivery of nicotine begin to develop throughout the brain. Over time, the brain begins to treat nicotine as necessary for our survival, not unlike food and water.
Given that nicotine leaves the body quickly, the brain needs access to a constant supply of nicotine in order to fill the receptors that keep the dopamine pathways active. As nicotine levels drop, so do dopamine levels. The outcome of this is the physical sensation we refer to as cravings for nicotine and the cigarettes that provide it.
To make matters worse, a process called up-regulation occurs the moment you start smoking. Up-regulation is when the number of receptors on a neurons dendrites increase. This means that more nicotine is required for a neuron to trigger the pathways that lead to the reward centre of the brain and release dopamine. The more you smoke, the more often you will need to smoke in order to maintain a satisfied feeling.
The Long Term Effect of Nicotine Addiction.
Once a smoker is chemically dependent on nicotine, the addiction progressively worsens. As time goes on, neural pathways begin to link cigarettes to more and more behaviors or actions that occur in the outside world.
Not only do these pathways grow in number, they are continuously reinforced and grow in strength. Eventually, the brain develops an incredibly strong and complex web of neural pathways that form connections to almost every emotion and external scenario imaginable.
A packet a day, twenty year smoker, has advanced chronic brain disease. Giving up the smokes is a lot more complicated than simply choosing to not light up. Thankfully, as with any treatable disease, a choice to seek treatment and undergo a healing process can lead to recovery.
In the final tutorial, we will explore the wonder of plasticity and down-regulation, and how by promoting these physiological events, a path to recovery is 100% achievable.
The below You Tube clips further demonstrate how addiction works.