Biology 102 DB 2

 Each thread must be 250 words and demonstrate course-related knowledge. Important Concepts from Chapter 13:

• Section 13.3: How Neurons Communicate The region where an axon terminal sends chemical signals to a neuron, a muscle fiber, or a gland cell is a chemical synapse. Axon terminals have synaptic vesicles filled with neurotransmitter, a signaling molecule that relays messages between cells at a synapse. The plasma membrane of a postsynaptic cell has receptor proteins that reversibly bind neurotransmitter. How a receiving cell responds depends on the type and amount of the neurotransmitter, the kinds of receptors, and other factors. Certain drugs can block reuptake of neurotransmitters.
• Section 13.13: The Brain on Mind Altering Drugs Drugs such as morphine and heroin mimic a neurotransmitter’s effect on a postsynaptic cell; they bind to receptors for endorphins (natural pain relievers), and elicit pain relief and feelings of well-being. Caffeine binds and inactivates receptors for adenosine, a neurotransmitter that causes drowsiness. Alcohol encourages drowsiness by releasing adenosine. Other drugs interfere with reuptake of neurotransmitter from the synaptic cleft. For example, cocaine slows reuptake of several neurotransmitters, including dopamine.

Assignment:

1. Visit the NIH National Institute on Drug Abuse and read the article Drugs, Brains and Behavior: The Science of Drug Addiction.

2. Go to Indiana University and read an article on Addictive Behaviors.

Prompt : - Using the sources provided, briefly describe one factor that can increase the risk of drug addiction, and one protective factor that can reduce the risk of drug addiction. - Why do you think Americans use so many legal drugs (e.g., alcohol, tobacco, and OTC drugs)?

Replies: Reply to 2 classmates, describing an additional risk factor and protective factor. Note: your factors should differ from the post to which you are replying and also those used in your other reply.