title: Hyperactivity and depression-like traits in Bax KO mice.
abstract: The Bax gene is a member of the Bcl-2 gene family and its pro-apoptotic Bcl-associated X (Bax) protein is believed to be crucial in regulating apoptosis during neuronal development as well as following injury. With the advent of mouse genomics, mice lacking the pro-apoptotic Bax gene (Bax KO) have been extensively used to study how cell death helps to determine synaptic circuitry formation during neurodevelopment and disease. Surprisingly, in spite of its wide use and the association of programmed neuronal death with motor dysfunctions and depression, the effects of Bax deletion on mice spontaneous locomotor activity and depression-like traits are unknown. Here we examine the behavioral characteristics of Bax KO male mice using classical paradigms to evaluate spontaneous locomotor activity and depressive-like responses. In the open field, Bax KO animals exhibited greater locomotor activity than their control littermates. In the forced swimming test, Bax KO mice displayed greater immobility times, a behavior despair state, when compared to controls. Collectively, our findings corroborate the notion that a fine balance between cell survival and death early during development is critical for normal brain function later in life. Furthermore, it points out the importance of considering depressive-like and hyperactivity behavioral phenotypes when conducting neurodevelopmental and other studies using the Bax KO strain.
authors.affiliation: Departamento de Ciências Fisiológicas, IBRAG, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil; Department of Anatomy and Neurobiology, Virginia Commonwealth University Medical Center, Richmond, USA.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Krahe
authors.affiliation: Department of Pediatrics, University of Maryland, Baltimore, USA.
authors.forename: Alexandre E
authors.initials: AE
authors.lastname: Medina
authors.affiliation: Department of Biology, University of Maryland, College Park, USA.
authors.forename: Crystal L
authors.initials: CL
authors.lastname: Lantz
authors.affiliation: Departamento de Ciências Fisiológicas, IBRAG, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: ccfilg@pq.cnpq.br.
authors.forename: Cláudio C
authors.initials: CC
authors.lastname: Filgueiras
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002470:Cell Survival / Q000235:genetics; D003863:Depression / Q000235:genetics* / Q000503:physiopathology; D004195:Disease Models, Animal; D005106:Exploratory Behavior / Q000502:physiology; D006948:Hyperkinesis / Q000235:genetics* / Q000503:physiopathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D013550:Swimming / Q000523:psychology; D013997:Time Factors; D051028:bcl-2-Associated X Protein / Q000172:deficiency* / Q000235:genetics
chemical_list: C494827:Bax protein, mouse; D051028:bcl-2-Associated X Protein
keywords: Apoptosis; Bcl-2 protein family; Behavior despair; Behavioral phenotyping; Depressive-like behavior; Locomotor hyperactivity; Neuronal cell death