How Drugs Alter The Brain

Remembering the Basics…. The brain is composed of millions of interconnecting nerve cells, called NEURONS. Each neuron is composed of: Axon: long single fiber, ending in thousands of nerve endings that transmit or send messages from the cell body to the dendrites of other neurons. Dendrite: short fibers that receive messages from other neurons and relay them to the cell body. Cell Body: contains the DNA/genetic blueprint, the cell body processes the information and directs the activities of the neuron. Synapse/Synaptic Gap – the space between the neurons

Remember…. The Areas of The Brain Brain Stem (survival – breathing etc..) Cerebellum (coordination, balance) Sensory Cortex (senses) Prefrontal Cortex (decision making, judgement, regulating emotions, etc…) Limbic System (feelings and emotions)

Remember This… An electrical signal (message) moves down an axon This triggers a specific neurotransmitter to be released into the synapse It carries the message and is received at the dendrite of another neuron.

How does the Brain Communicate?? Neurotransmission = communication between brain cells (In order for the brain to function so that a person can think, move, or feel, neurons must communicate – this is called neurotransmission) Neurotransmitters = chemicals that carry messages around in the brain. (dopamine, serotonin, adrenaline, etc..)

Neuron Axon Dendrite Message a chemical that will carry the message

All of that should have been REVIEW!!!! Different Neurotransmitters are attracted to different receptors and trigger different messages. Much like the way a key fits into a lock. If the key fits, the receiving neuron will be able to process the signal and send it on. All of that should have been REVIEW!!!!

Now for the new stuff… When Drugs are Introduced Once introduced, drugs change how the brain works. Regardless of whether a drug is swallowed, sniffed, inhaled, injected, absorbed etc… drugs will eventually travel through the circulatory system and reach the brain. Pathways To The Brain http://science-education.nih.gov/supplements/nih2/addiction/activities/lesson3_pathways.htm

Drugs in the Brain Once in the brain, drugs can affect almost any step in the communication between neurons. Drugs can stimulate or activate our natural chemicals. Drugs can also imitate or mimic our natural chemicals. Drugs can eventually replace our own natural chemicals. Drugs can damage and destroy receptors, so that messages cannot be received by certain neurons.

Drugs Fool The Brain When drugs trick the brain a temporary pleasurable sensation occurs. This exceeds pleasure felt by “normal” things…. Yummy food, funny movie etc… The brain likes pleasure and wants more, so it tells you to get more.

What happens after??? Once drugs are out of your system, you don’t go back to normal. Things that once gave you pleasure are NOT as pleasurable. Your body feels the negative effects – you feel the opposite of the high.

AND THEN…. This causes withdrawal symptoms - psychological (anxiety, stress, depression, paranoia) and/or physical (headaches, shakes, sick feeling) You need to use even MORE of the drug to feel the same pleasure next time. (tolerance develops)

How does the brain adapt to the drugs? (Neuroadaptaion) Not only does the brain like to feel good – it also likes to be in BALANCE. The brain adjusts by increasing or decreasing the actual number of receptors to try BALANCE the extremes. The brain adjusts by decreasing the amount of our natural “feel good” chemicals that are produced to try to BALANCE the extremes…

So then what?? The user gets stuck in this “addiction” They want the high the drug gave them, their brain CRAVES it. But their brain can’t handle all the chemicals – so it tries to BALANCE things out. BRAIN CHEMISTRY and FUNCTIONING is altered and people get stuck in this cycle!!!

How addiction changes your brain – YouTube Explain it to me: Addiction – YouTube The Science of Addiction - YouTube