1)5-HT1A, 5-HT4, and 5-HT6 receptors have all been implicated in processes of learning and memory

1)5-HT1A, 5-HT4, and 5-HT6 receptors have all been implicated in processes of learning and memory. Describe the experimental findings obtained from laboratory animals that implicate each receptor subtype, including the brain area(s) of receptor expression thought to be important for each subtype.

2)What are the sources of 5-HT in the GI tract, and why are pharmacologists interested in 5-HT from these sources? Include in your answer a discussion of the clinical relevance of gut 5-HT, including serotonergic medications that have been developed to treat GI disorders.