23.22: Alcohol interferes with many different neurotransmitters.

So far, we’ve seen that drugs frequently can alter our brain functioning by mimicking the neurotransmitters used by our neurons during normal functioning. Their specific effects are quite predictable, as long as we know the neurotransmitter that a particular drug mimics. Their work is like a surgical strike, altering our neurochemistry in one specific way.

But what happens if the drug is more of an everyman, looking enough like many different neurotransmitters to impersonate them all? This is the case with alcohol. More specifically, it is the case with ethanol, the “alcohol” molecule in alcoholic beverages. Alcohol is a great neurotransmitter impersonator, fooling at least four different receptor molecules. Let’s look at some of its effects (FIGURE 23-51).

Figure 23.51: Alcohol impersonates several neurotransmitters, with several consequences.
Figure 23.52: Alcohol intake lowers inhibitions and, in excess, can increase the likelihood of risky behavior.

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For most people, moderate alcohol consumption is pleasant and does not have significant health risks. For some, however, alcohol abuse and alcoholism can lead to serious problems. Nearly 14 million Americans abuse alcohol, and the consequences can be serious. Beyond the effects it creates by mimicking neurotransmitters, alcohol has a variety of other physiological effects in our bodies that can become harmful when alcohol is consumed in large amounts or for long periods of time. These include increasing the risk for some types of cancer, increasing the risk of liver disease (because the liver must metabolize and detoxify all the ethanol molecules that are consumed), increasing the likelihood of harm to the fetus during pregnancy, increasing the likelihood of taking part in risky sexual and other behaviors, and increasing the risk of automobile crashes (FIGURE 23-52).

TAKE-HOME MESSAGE 23.22

Alcohol affects the functioning of multiple neurotransmitters—including glutamate, endorphins, dopamine, and serotonin—slowing reaction times, slurring speech, blocking pain, and increasing contentment.

What are some of the risks associated with long-term alcohol use?

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