title: The role of galanin system in modulating depression, anxiety, and addiction-like behaviors after chronic restraint stress.
abstract: There is high comorbidity between stress-related psychiatric disorders and addiction, suggesting they may share one or more common neurobiological mechanisms. Because of its role in both depressive and addictive behaviors, the galanin system is a strong candidate for such a mechanism. In this study, we tested if galanin and its receptors are involved in stress-associated behaviors and drug addiction. Mice were exposed to 21 days of chronic restraint stress (CRS); subsequently, mRNA levels of galanin, galanin receptors (GalRs), the rate-limiting enzymes for the synthesis of monoamines, and monoamine autoreceptors were measured in the nucleus accumbens by a quantitative real-time polymerase chain reaction. Moreover, we tested the effects of this stress on morphine-induced addictive behaviors. We found that CRS induced anxiety and depression-like behaviors, impaired the formation and facilitated the extinction process in morphine-induced conditioned place preference (CPP), and also blocked morphine-induced behavioral sensitization. These behavioral results were accompanied by a CRS-dependent increase in the mRNA expression of galanin, GalR1, tyrosine hydroxylase (TH), tryptophan hydroxylase 2, and 5-HT1B receptor. Interestingly, treatment with a commonly used antidepressant, fluoxetine, normalized the CRS-induced behavioral changes based on reversing the higher expression of galanin and TH while increasing the expression of GalR2 and α2A-adrenceptor. These results indicate that activating the galanin system, with corresponding changes to noradrenergic systems, following chronic stress may modulate stress-associated behaviors and opiate addiction. Our findings suggest that galanin and GalRs are worthy of further exploration as potential therapeutic targets to treat stress-related disorders and drug addiction.
authors: Department of Forensic Science, Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi 710061, PR China.
authors: X
authors: X
authors: Zhao
authors: R R
authors: RR
authors: Seese
authors: K
authors: K
authors: Yun
authors: T
authors: T
authors: Peng
authors: Z
authors: Z
authors: Wang
mesh_terms: D000818:Animals; D001007:Anxiety / Q000378:metabolism* / Q000523:psychology; D016739:Behavior, Addictive / Q000378:metabolism* / Q000523:psychology; D002908:Chronic Disease; D003863:Depression / Q000378:metabolism* / Q000523:psychology; D019004:Galanin / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000502:physiology; D009714:Nucleus Accumbens / Q000378:metabolism; D011897:Random Allocation; D044091:Receptor, Galanin, Type 1 / Q000502:physiology*; D044092:Receptor, Galanin, Type 2 / Q000502:physiology*; D012149:Restraint, Physical; D013315:Stress, Psychological / Q000378:metabolism* / Q000523:psychology
chemical_list: D044091:Receptor, Galanin, Type 1; D044092:Receptor, Galanin, Type 2; D019004:Galanin