title: The effects of fluoxetine treatment in a chronic mild stress rat model on depression-related behavior, brain neurotrophins and ERK expression.
abstract: Depression is associated with hippocampus (HC) volume loss. Chronic mild stress (CMS) in rats is a model of depression. Antidepressants attenuate HC volume loss and reverse the depression-like symptoms of stressed animals. We evaluated the effect of CMS and the selective serotonin reuptake inhibitor, fluoxetine (FLX) treatment on behavioral and cognitive parameters in rats, and on HC and frontal cortex (FC) neurotrophic factors levels. Male rats were exposed sequentially, over a period of 5 weeks, to a variety of mild stressors. FLX (5 mg/kg/day ip) was administered to the stressed group and controls (unstressed). After 5 of CMS, animals were tested using the Morris Water Maze (MWM). In the MWM, we observed that FLX had a transitory effect on unstressed rats. CMS reduced insulin-like growth factor-1 receptor (IGF-1R) levels in the HC whereas after FLX treatment these levels reverted to normal range. CMS rats revealed a significant decrease in extracellular signal-regulated kinase (ERK) phosphorylation in both HC and FC regions, while FLX normalized these levels. This study suggests that IGF-1R and ERK may have a role in mediating the neural stress response and the mode of action of FLX. This role seems to be independent of the BDNF alterations.
authors.affiliation: Laboratory of Biological Psychiatry, Felsenstein Medical Research Center and Sackler Faculty of Medicine, Tel-Aviv University, Beilinson Campus, 49100 Petah Tikva, Israel.
authors.forename: Maya
authors.initials: M
authors.lastname: First
authors.forename: Irit
authors.initials: I
authors.lastname: Gil-Ad
authors.forename: Michal
authors.initials: M
authors.lastname: Taler
authors.forename: Igor
authors.initials: I
authors.lastname: Tarasenko
authors.forename: Nurit
authors.initials: N
authors.lastname: Novak
authors.forename: Abraham
authors.initials: A
authors.lastname: Weizman
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D001921:Brain / Q000033:anatomy & histology / Q000187:drug effects* / Q000378:metabolism; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D003863:Depression / Q000188:drug therapy*; D004195:Disease Models, Animal; D004435:Eating / Q000187:drug effects; D005106:Exploratory Behavior / Q000187:drug effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D005473:Fluoxetine / Q000494:pharmacology / Q000627:therapeutic use; D007858:Learning / Q000187:drug effects; D008297:Male; D009414:Nerve Growth Factors / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D013315:Stress, Psychological / Q000503:physiopathology*
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D048049:Extracellular Signal-Regulated MAP Kinases; D005473:Fluoxetine; D009414:Nerve Growth Factors; D017367:Selective Serotonin Reuptake Inhibitors