Nicotinic and Opioid Receptor Interactions in Nicotine Addiction

A diagram of the modification of dopamine release dynamics by nAChRs on dopamine terminals. A. The illustration indicates control conditions, where endogenous ACh release from cholinergic interneurons causes a high probability of dopamine release. Low frequency stimulation results in dopamine release that is very similar to that seen with high frequency burst-type stimulation. B. Nicotine treatment (upper panel) desensitizes the presynaptic nAChRs on the dopamine terminals, lowering release probability and decreasing the dopamine secretion elicited by low frequency stimulation. Under these conditions, high frequency burst firing (lower panel) causes more dopamine release than that seen under control conditions. Similar effects are seen with nAChR antagonists.