title: The effects of pregnancy, lactation, and primiparity on object-in-place memory of female rats.
abstract: Maternal physiology and behavior change dramatically over the course of pregnancy to nurture the fetus and prepare for motherhood. Further, the experience of motherhood itself continues to influence brain functioning well after birth, shaping behavior to promote the survival of offspring. To meet these goals, cognitive abilities, such as spatial memory and navigation, may be enhanced to facilitate foraging behavior. Existing studies on pregnant and maternal rats demonstrate enhanced cognitive function in specific spatial domains. We adopted a novel object-in-place task to assess the ability of female rats to integrate information about specific objects in specific locations, a critical element of foraging behavior. Using a longitudinal design to study changes in spatial memory across pregnancy and motherhood, an advantage in the object-in-place memory of primiparous female rats compared to nulliparous females emerged during lactation not during pregnancy, and was maintained after weaning at 42 days postpartum. This enhancement was not dependent on the non-mnemonic variables of anxiety or neophobia. Parity did not affect the type of learning strategy used by females to locate a cued escape platform on a dual-solution water maze task. Results indicate that the enhancement of object-in-place memory, a cognitive function that facilitates foraging, emerged after pregnancy during the postpartum period of lactation and persisted for several weeks after weaning of offspring.
authors.affiliation: Program in Neuroscience, Tulane University, 2004 Percival Stern Hall, 6400 Freret Street, New Orleans, LA 70115 USA. Electronic address: kcost@tulane.edu.
authors.forename: Katherine Tombeau
authors.initials: KT
authors.lastname: Cost
authors.affiliation: Program in Neuroscience, Tulane University, 2004 Percival Stern Hall, 6400 Freret Street, New Orleans, LA 70115 USA.
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Lobell
authors.affiliation: Program in Neuroscience, Tulane University, 2004 Percival Stern Hall, 6400 Freret Street, New Orleans, LA 70115 USA; Department of Psychology, Tulane University, 2007 Percival Stern Hall, 6400 Freret Street, New Orleans, LA 70115 USA.
authors.forename: Zari N
authors.initials: ZN
authors.lastname: Williams-Yee
authors.affiliation: Department of Biology, Xavier University, 1 Drexel Drive New Orleans, LA 70125 USA.
authors.forename: Sherryl
authors.initials: S
authors.lastname: Henderson
authors.affiliation: Program in Neuroscience, Tulane University, 2004 Percival Stern Hall, 6400 Freret Street, New Orleans, LA 70115 USA; Department of Psychology, Tulane University, 2007 Percival Stern Hall, 6400 Freret Street, New Orleans, LA 70115 USA.
authors.forename: Gary
authors.initials: G
authors.lastname: Dohanich
mesh_terms: D000818:Animals; D003071:Cognition / Q000502:physiology; D003216:Conditioning, Operant / Q000502:physiology; D003463:Cues; D030762:Estrous Cycle / Q000502:physiology; D005239:Fear / Q000502:physiology; D005260:Female; D007774:Lactation / Q000523:psychology*; D008098:Litter Size; D008297:Male; D018782:Maze Learning / Q000502:physiology; D008568:Memory / Q000502:physiology*; D010298:Parity / Q000502:physiology*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000523:psychology*; D011597:Psychomotor Performance / Q000502:physiology; D051381:Rats; D020318:Rats, Long-Evans; D012744:Sex Ratio; D014886:Weaning
keywords: Lactation; Memory; Object-in-place; Pregnancy; Spatial