Teachable moment in classrooms:
- nervous tissue chapter – using neurotransmitters in synaptic communication between neurons
- nervous tissue chapter – anatomy of the brain, the five lobes
- nervous tissue chapter – basic cellular structures of neurons, axon, cell body
The news item: Recently the following report appeared online:
Why a Brain Injury From a Stroke Cured a Smoking Addiction
Scientists are learning new ways we might be able to permanently cure addiction in the future.
The article states that in the USA over 27 million adults suffer from addiction to various substances, and that for a portion of those people current treatments are not effective. Researchers started a new study when sporadic evidence emerged that brain lesions caused addicted smokers to stop smoking. This article mentions the insular area, frontal lobe where brain damage correlated with cessation of addiction to smoking.
So, Why Do I Care?? To be more accurate than the article, over 27 million people in the USA suffered from addiction during the year 2022. The relapse rate (the return to addictive substance use) can reach as high as 60% of those people. The impact of addiction on the individual ranges from deterioration of health, problems of employability, and limited social interactions. According to estimates, the yearly economic cost of addiction is over $500 billion for the US. There is also a cost on personal relationships, and this is difficult to measure. Finding new biological pathways that are part of addictions can result in new, more effective treatments.
Plain English, Please!!! First, let’s talk about the anatomy of the nervous system linked to addiction. Addiction activates the reward centers in our brain, causing the perception of satisfaction, pleasure. Those centers are located in the brainstem, and in the basal ganglia, and the centers are made up of millions of neurons. Those centers are receiving stimulation or inhibition from other parts of the brain, such as the frontal lobe of the cerebrum, and the amygdala. These areas also represent millions of neurons. Think about this like a spider (the mass of neurons of the reward center) sitting in the middle of the spider web made up by the millions of axons coming from those other brain parts. Imagine that the stimulating nerve impulses pull the spider web to the right, while the inhibiting nerve impulses pull the spider web to the left. The reward center (the spider) will move to the right to consume the addictive substance, or move to the left to resist the urge to consume.
Second, let’s talk about how different brain parts influence the reward center. The influence of inhibition or stimulation of the reward center is carried out by neurotransmitters that are small molecules acting at