8: Opioids binding to opioid receptors in the nucleus accumbens: increased dopamine release
Show how opioids activate the reward system using the nucleus accumbens as an example. Explain that the action is a little more complicated than cocaine's because more than two neurons are involved. Point out that 3 neurons participate in opioid action; the dopamine terminal, another terminal (on the right) containing a different neurotransmitter (probably GABA for those that would like to know), and the post-synaptic cell containing dopamine receptors. Show that opioids bind to opioid receptors (green) on the neighboring terminal and this sends a signal to the dopamine terminal to release more dopamine. [In case an inquisitive student asks how - one theory is that opioid receptor activation decreases GABA release, which normally inhibits dopamine release - so dopamine release is increased.]
Cite this article
NIDA. (2019, November 19). The Brain & the Actions of Cocaine, Opioids, and Marijuana. Retrieved from https://www.drugabuse.gov/brain-actions-cocaine-opioids-marijuana
Explores the consequences of drug abuse on the brain and body and introduces the topics of prevention, and treatment.