title: Neonatal interventions differently affect maternal care quality and have sexually dimorphic developmental effects on corticosterone secretion.
abstract: Neonatal handling (H) and maternal separation (MS) both induce changes in maternal care, but the contribution of these changes to the behavioral and neurochemical outcomes of the offspring remains unclear, as studies often find opposite results concerning the frequency of maternal behaviors, particularly in the MS paradigm. In this study, behavior displayed by H, MS and non-handled (NH) Wistar rat dams were observed during the first 10days after birth. A tentative assessment of the quality of maternal care was made, using a previously reported score that reflects behavior fragmentation and inconsistency. Central oxytocin levels and hippocampal synaptic plasticity markers were also evaluated in dams, immediately after litter weaning. In adulthood, male and female offspring were subjected to a contextual stress-induced corticosterone challenge to provide further information on the impact of early interventions on neuroendocrine parameters. We found that while both H and MS interventions induced an increase in the amount of pup-directed behavior, MS dams displayed a more fragmented and inconsistent pattern of care, reflecting poorer maternal care quality. Interestingly, an increase in oxytocin levels was observed only in H dams. While H offspring did not differ from NH, MS males and females showed marked differences in corticosterone secretion compared to controls. Our results suggest that briefly removing the pups from the nest alters maternal care quantity but not quality and increases central oxytocin, while long separations appear to increase low quality maternal care and change neuroendocrine responses in adult offspring in a sex-specific manner.
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil. Electronic address: natividade.pereira@gmail.com.
authors.forename: Natividade de Sá
authors.initials: NS
authors.lastname: Couto-Pereira
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Neurociências, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Núcleo de Estudos da Saúde da Criança e do Adolescente, Hospital de Clínicas de Porto Alegre (HCPA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: Charles Francisco
authors.initials: CF
authors.lastname: Ferreira
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: Carine
authors.initials: C
authors.lastname: Lampert
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: Danusa Mar
authors.initials: DM
authors.lastname: Arcego
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Toniazzo
authors.affiliation: Núcleo de Estudos da Saúde da Criança e do Adolescente, Hospital de Clínicas de Porto Alegre (HCPA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: Juliana Rombaldi
authors.initials: JR
authors.lastname: Bernardi
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: Diego Carrilho
authors.initials: DC
authors.lastname: da Silva
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Von Poser Toigo
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: Luisa Amalia
authors.initials: LA
authors.lastname: Diehl
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: Rachel
authors.initials: R
authors.lastname: Krolow
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Neurociências, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Núcleo de Estudos da Saúde da Criança e do Adolescente, Hospital de Clínicas de Porto Alegre (HCPA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: Patrícia Pelufo
authors.initials: PP
authors.lastname: Silveira
authors.affiliation: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Programa de Pós-Graduação em Ciências Biológicas: Neurociências, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
authors.forename: Carla
authors.initials: C
authors.lastname: Dalmaz
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D003345:Corticosterone / Q000097:blood*; D005260:Female; D006234:Handling, Psychological; D006624:Hippocampus / Q000378:metabolism; D008297:Male; D008426:Maternal Deprivation; D001523:Mental Disorders / Q000097:blood / Q000209:etiology; D010121:Oxytocin / Q000134:cerebrospinal fluid; D010147:Pain Measurement; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D012727:Sex Characteristics; D016708:Synaptophysin / Q000378:metabolism
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D016708:Synaptophysin; D010121:Oxytocin; D003345:Corticosterone
keywords: Behavior inconsistency; Central oxytocin; Corticosterone; Maternal care; Maternal separation; Neonatal handling