Aversion: Amygdala-prefrontal coupling depends on a genetic variation of the serotonin transporter.

Entrez PubMed: "Major depression is conditionally linked to a polymorphism of the human serotonin transporter gene (SLC6A4). During the presentation of aversive, but not pleasant, pictures, healthy carriers of the SLC6A4 short (s) allele showed stronger activation of the amygdala on functional magnetic resonance imaging. s carriers also showed greater coupling between the amygdala and the ventromedial prefrontal cortex, which may contribute to the abnormally high activity in the amygdala and medial prefrontal cortex seen in major depression."

Amygdala-prefrontal coupling depends on a genetic variation of the serotonin transporter.
Heinz A, Braus DF, Smolka MN, Wrase J, Puls I, Hermann D, Klein S, Grusser SM, Flor H, Schumann G, Mann K, Buchel C.
Nat Neurosci. 2005 Jan;8(1):20-1. Epub 2004 Dec 12.