title: Gastrectomy alters emotional reactivity in rats: neurobiological mechanisms.
abstract: Gastrectomy (Gsx) is associated with altered emotional function and a predisposition to depression/anxiety disorders. Here we investigated the effects of Gsx on emotional reactivity in rats and explored the underlying neurobiological mechanisms. Gsx- and sham-operated rats were exposed to behavioural tests that explore anxiety- and depression-like behaviour (open field, black and white box, elevated plus maze, social interaction, forced swim) as well as memory (object recognition). The potential neurobiological mechanisms underlying these differences were explored by measuring (i) turnover of candidate neurotransmitter systems in the nucleus accumbens, (ii) hippocampal neurogenesis by BrdU labelling or by analysis of candidate genes involved in neuronal growth and (iii) changes in mRNA expression of candidate genes in dissected hippocampal and amygdala tissue. Data from individual behavioural tests as well as from multivariate analysis revealed differing emotional reactivity between Gsx- and sham-operated rats. Gsx rats showed reduced emotional reactivity in a new environment and decreased depression-like behaviour. Accumbal serotonin and dopamine turnover were both reduced in Gsx rats. Gsx also led to a memory deficit, although hippocampal neurogenesis was unaffected. Of the many candidate genes studied by real-time RT-PCR, we highlight a Gsx-associated decrease in expression of Egr-1, a transcription factor linked to neural plasticity and cognition, in the hippocampus and amygdala. Thus, Gsx induces an alteration of emotional reactivity and a memory/cognitive deficit that is associated with reduced turnover of serotonin and dopamine in the nucleus accumbens and decreased expression of Egr-1 in the hippocampus and amygdala.
authors.affiliation: Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 11, SE-40530 Gothenburg, Sweden.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Salomé
authors.forename: Magdalena
authors.initials: M
authors.lastname: Taube
authors.forename: Emil
authors.initials: E
authors.lastname: Egecioglu
authors.forename: Caroline
authors.initials: C
authors.lastname: Hansson
authors.forename: Björn
authors.initials: B
authors.lastname: Stenström
authors.forename: Duan
authors.initials: D
authors.lastname: Chen
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Andersson
authors.forename: H
authors.initials: H
authors.lastname: Georg Kuhn
authors.forename: Claes
authors.initials: C
authors.lastname: Ohlsson
authors.forename: Suzanne L
authors.initials: SL
authors.lastname: Dickson
mesh_terms: D000679:Amygdala / Q000166:cytology / Q000378:metabolism; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D003071:Cognition / Q000502:physiology; D003345:Corticosterone / Q000097:blood; D004298:Dopamine / Q000378:metabolism; D051766:Early Growth Response Protein 1 / Q000235:genetics / Q000378:metabolism; D004644:Emotions / Q000502:physiology*; D005743:Gastrectomy; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D006801:Humans; D008297:Male; D018782:Maze Learning / Q000502:physiology; D008568:Memory / Q000502:physiology; D015999:Multivariate Analysis; D055495:Neurogenesis / Q000502:physiology; D009483:Neuropsychological Tests; D025341:Principal Component Analysis; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism
chemical_list: D051766:Early Growth Response Protein 1; C486110:Egr1 protein, rat; D012333:RNA, Messenger; D012701:Serotonin; D004298:Dopamine; D003345:Corticosterone