title: Maternal and affective behaviors of lactating rats reared in overlapping litters.
abstract: Postpartum mating in rats gives rise to complex family units consisting of the mother and two overlapping litters. As a consequence, newborn pups of the second litter, since the moment they are born, acquire experience not only from interaction with the mother and age-matched littermates but also from interaction with older siblings. Newborn pups reared in overlapping litters (OLs) receive a different pattern of maternal stimulation compared to those reared in single litters (SL: one litter of same aged pups), as the mothers reduce some maternal behavior components and juvenile pups from the first litter develop maternal behavior. Since there is strong evidence showing that variations in maternal behavior are transmitted throughout generations, we hypothesized that the altered pattern of maternal stimulation received by OL reared females would modify their behavior during motherhood. To test this hypothesis maternal behavior, maternal aggression and experimental anxiety of dams reared under OL and SL conditions during the first postpartum week were compared. No differences were found between the groups in their maternal behavior and aggression. This result may be explained by the maternal behavior of the juveniles that could compensate for the deficits in the caregiving behaviors received by OL litters. However, a subtle temporal reorganization of the licking behavior was found in OL reared mothers, together with an increased anxiety-related behavior in the plus maze test. These results suggest dissociation in the effects provoked by early environmental alterations on different behavioral systems, and more importantly, that independently of their early family composition, both groups can cope effectively with the changing demands of the pups.
authors.affiliation: Laboratorio de Neurociencias, Sección Biomatemática, Facultad de Ciencias, Universidad de la República, Uruguay; Laboratorio de Experimentación Animal, Facultad de Ciencias, Universidad de la República, Uruguay. Electronic address: natiuria@gmail.com.
authors.forename: Natalia
authors.initials: N
authors.lastname: Uriarte
authors.affiliation: Laboratorio de Neurociencias, Sección Biomatemática, Facultad de Ciencias, Universidad de la República, Uruguay; Laboratorio de Experimentación Animal, Facultad de Ciencias, Universidad de la República, Uruguay.
authors.forename: María Victoria
authors.initials: MV
authors.lastname: Fernández
authors.affiliation: Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Uruguay; Laboratorio de Experimentación Animal, Facultad de Ciencias, Universidad de la República, Uruguay.
authors.forename: Daniella
authors.initials: D
authors.lastname: Agrati
authors.affiliation: Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Uruguay; Laboratorio de Experimentación Animal, Facultad de Ciencias, Universidad de la República, Uruguay.
authors.forename: María José
authors.initials: MJ
authors.lastname: Zuluaga
authors.affiliation: Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Uruguay; Laboratorio de Experimentación Animal, Facultad de Ciencias, Universidad de la República, Uruguay.
authors.forename: Marcela
authors.initials: M
authors.lastname: Ferreño
authors.affiliation: Sección Fisiología y Nutrición, Facultad de Ciencias, Universidad de la República, Uruguay; Laboratorio de Experimentación Animal, Facultad de Ciencias, Universidad de la República, Uruguay.
authors.forename: Annabel
authors.initials: A
authors.lastname: Ferreira
mesh_terms: D000339:Affect / Q000502:physiology*; D000374:Aggression / Q000502:physiology; D000818:Animals; D001007:Anxiety / Q000523:psychology; D001522:Behavior, Animal / Q000502:physiology*; D005260:Female; D007774:Lactation / Q000502:physiology*; D008297:Male; D008425:Maternal Behavior / Q000502:physiology*; D009425:Nesting Behavior; D017440:Photoperiod; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D012931:Social Environment
keywords: Communal nesting; Early experience; Experimental anxiety; Lactation; Maternal aggression; Maternal behavior; Overlapping litters; Rat