title: Reduced evoked fos expression in activity-related brain regions in animal models of behavioral depression.
abstract: A previous study showed that two mouse models of behavioral depression, immune system activation and depletion of brain monoamines, are accompanied by marked reductions in stimulated neural activity in brain regions involved in motivated behavior. The present study tested whether this effect is common to other depression models by examining the effects of repeated forced swimming, chronic subordination stress or acute intraventricular galanin injection - three additional models - on baseline or stimulated c-fos expression in several brain regions known to be involved in motor or motivational processes (secondary motor, M2, anterior piriform cortex, APIR, posterior cingulate gyrus, CG, nucleus accumbens, NAC). Each of the depression models was found to reduce the fos response stimulated by exposure to a novel cage or a swim stress in all four of these brain areas but not to affect the response of a stress-sensitive region (paraventricular hypothalamus, PVH) that was included for control purposes. Baseline fos expression in these structures was either unaffected or affected in an opposite direction to the stimulated response. Pretreatment with either desmethylimipramine (DMI) or tranylcypromine (tranyl) attenuated these changes. It is concluded that the pattern of a reduced neural function of CNS motor/motivational regions with an increased function of stress areas is common to 5 models of behavioral depression in the mouse and is a potential experimental analog of the neural activity changes occurring in the clinical condition.
authors.affiliation: Department of Psychiatry, New York University School of Medicine, 550 First Ave, New York, NY 10016, United States. eric.stone@eny.edu
authors.forename: Eric A
authors.initials: EA
authors.lastname: Stone
authors.forename: Michael L
authors.initials: ML
authors.lastname: Lehmann
authors.forename: Yan
authors.initials: Y
authors.lastname: Lin
authors.forename: David
authors.initials: D
authors.lastname: Quartermain
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000928:Antidepressive Agents / Q000008:administration & dosage; D001522:Behavior, Animal; D003863:Depression / Q000209:etiology / Q000378:metabolism* / Q000473:pathology* / Q000517:prevention & control; D003891:Desipramine / Q000008:administration & dosage; D004195:Disease Models, Animal; D004291:Dominance-Subordination; D046352:Freezing Reaction, Cataleptic / Q000187:drug effects / Q000502:physiology; D019004:Galanin; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D051379:Mice; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D013315:Stress, Psychological / Q000150:complications; D013550:Swimming / Q000523:psychology; D013997:Time Factors; D014191:Tranylcypromine / Q000008:administration & dosage
chemical_list: D000928:Antidepressive Agents; D016760:Proto-Oncogene Proteins c-fos; D014191:Tranylcypromine; D019004:Galanin; D003891:Desipramine