title: Ancestral Exposure to Stress Generates New Behavioral Traits and a Functional Hemispheric Dominance Shift.
abstract: In a continuously stressful environment, the effects of recurrent prenatal stress (PS) accumulate across generations and generate new behavioral traits in the absence of genetic variation. Here, we investigated if PS or multigenerational PS across 4 generations differentially affect behavioral traits, laterality, and hemispheric dominance in male and female rats. Using skilled reaching and skilled walking tasks, 3 findings support the formation of new behavioral traits and shifted laterality by multigenerational stress. First, while PS in the F1 generation did not alter paw preference, multigenerational stress in the F4 generation shifted paw preference to favor left-handedness only in males. Second, multigenerational stress impaired skilled reaching and skilled walking movement abilities in males, while improving these abilities in females beyond the levels of controls. Third, the shift toward left-handedness in multigenerationally stressed males was accompanied by increased dendritic complexity and greater spine density in the right parietal cortex. Thus, cumulative multigenerational stress generates sexually dimorphic left-handedness and dominance shift toward the right hemisphere in males. These findings explain the origins of apparently heritable behavioral traits and handedness in the absence of DNA sequence variations while proposing epigenetic mechanisms.
authors.affiliation: Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, CanadaT1K 3M4.
authors.forename: Mirela
authors.initials: M
authors.lastname: Ambeskovic
authors.affiliation: Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, CanadaT1K 3M4.
authors.forename: Nasrin
authors.initials: N
authors.lastname: Soltanpour
authors.affiliation: Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, CanadaT1K 3M4.
authors.forename: Erin A
authors.initials: EA
authors.lastname: Falkenberg
authors.affiliation: Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, Canada T1K 3M4.|Department of Physiological Sciences, University of Brasilia, Brasilia, DF 70910-900, Brazil.
authors.forename: Fabiola C R
authors.initials: FCR
authors.lastname: Zucchi
authors.affiliation: Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, CanadaT1K 3M4.
authors.forename: Bryan
authors.initials: B
authors.lastname: Kolb
authors.affiliation: Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, CanadaT1K 3M4.
authors.forename: Gerlinde A S
authors.initials: GAS
authors.lastname: Metz
mesh_terms: D000818:Animals; D003712:Dendrites / Q000473:pathology / Q000502:physiology; D004292:Dominance, Cerebral / Q000235:genetics* / Q000502:physiology*; D044127:Epigenesis, Genetic; D005121:Extremities / Q000502:physiology; D005260:Female; D040582:Inheritance Patterns; D008297:Male; D009048:Motor Skills / Q000502:physiology; D010296:Parietal Lobe / Q000473:pathology / Q000503:physiopathology; D011897:Random Allocation; D020318:Rats, Long-Evans; D012727:Sex Characteristics; D013315:Stress, Psychological / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology*; D016138:Walking / Q000502:physiology
keywords: Golgi–Cox staining; behavioral laterality; brain dominance; dendritic morphology; dexterity; fine motor skills; handedness; multigenerational prenatal stress; neuroplasticity, parietal cortex (Par 1); sex differences; sexual dimorphism; spine density