Galanin mainly has a hyperpolarizing inhibitory effect and is implicated in anxiety, stress, depression and drug addiction, reviewed in Holmes and Picciotto (2006). Galanin and its receptors were decreased about 2 fold indicating a decreased function for this peptide in the DRN. Galanin receptors on serotonin neurons in the DRN can have an inhibitory effect on serotonin signaling (Holmes and Picciotto, 2006). Galr1 is linked to Gi/Go proteins which inhibit adenylyl cyclase. The decrease in Galanin and the receptor may contribute to the overall increase in CREB signaling seen in the DRN of these animals.
