Figure 1.

Opiate receptor activation of a nerve and blockage of the signal by naltrexone. A) Alcohol is thought to stimulate the release of endogenous opioids, which may produce the euphoric feelings associated with alcohol consumption. B) Endogenous opioids (e.g., beta-endorphin) are released into the synapse (the space between the signaling and target neurons) and C) stimulate activity at opiate receptors, which produces a signal in the target neuron. D) Exogenous opiates such as morphine also stimulate opiate receptors. E) Naltrexone is thought to block opioids from activating opiate receptors.