In order to understand the biochemistry of methamphetamine, we first need to understand the intricate network of neurons called the central nervous system (CNS) that controls everything in your body. The CNS consists of the neurons residing in the brain and the spinal cord, while everything outside of these two areas make up the peripheral nervous system (PNS). Everything outside of the brain and spinal cord means that the PNS consists of mostly nerves that extend from the brain and spinal cord into many other areas of the body. For example, there is a spinal nerve extending from your spinal cord to your toes (and back to the spinal cord) that allows you to wiggle your toes.
The PNS can be further divided into two systems: the somatic nervous system (SNS) and the autonomic nervous system (ANS). The SNS is in charge of the body’s voluntary movements, such a wiggling your toes whenever you want to. On the other hand, the ANS controls involuntary or automatic movements such as your heart rate. The ANS also consists of two other systems called the parasympathetic and sympathetic nervous system. These two systems work together to regulate the body’s response to any situation. The sympathetic system controls the “fight or flight” response and thus activates the involuntary activities that are involved in the body’s response to a stressful situation. The parasympathetic system maintains a “rest” response that keeps the body running smoothly under everyday situations. It also calms the body down after a “fight or flight” response. As you can see, all of these systems work to keep the body operating smoothly. As you learn more about methamphetamine, you will see how it alters the functioning of each of these systems.
In general, the biochemistry section provides you with basic information about the structure and function of neurons, neurotransmission, as well as detailed information about the neurotransmitters that are involved in methamphetamine use. If you want to a basic review, feel free to peruse through all the following pages. If you already have a good grasp on neurotransmission, you may just want to check out the pages on dopamine, serotonin, and norepinephrine.