Prenatal stress produces sex differences in nest odor preference.
Prenatal stress (PS) and early postnatal environment may alter maternal care. Infant rats learn to identify their mother through the association between maternal care and familiar odors. Female Wistar rats were exposed to restraint stress for 30 min, 4 sessions per day, in the last 7 days of pregnancy. At birth, pups were cross-fostered and assigned to the following groups: prenatal non-stressed mothers raising non-stressed pups (NS:NS), prenatal stressed mothers raising non-stressed pups (S:NS), prenatal non-stressed mothers raising stressed pups (NS:S), prenatal stressed mothers raising stressed pups (S:S). Maternal behaviors were assessed during 6 postpartum days. On postnatal day (PND) 7, the behavior of male and female pups was analyzed in the odor preference test; and noradrenaline (NA) activity in olfactory bulb (OB) was measured. The results showed that restraint stress increased plasma levels of corticosterone on gestational day 15. After parturition, PS reduced maternal care, decreasing licking the pups and increasing frequency outside the nest. Female pups from the NS:S, S:NS, S:S groups and male pups from the S:S group showed no nest odor preference. Thus, at day 7, female pups that were submitted to perinatal interventions showed more impairment in the nest odor preference test than male pups. No changes were detected in the NA activity in the OB. In conclusion, repeated restraint stress during the last week of gestation reduces maternal care and reduces preference for a familiar odor in rat pups in a sex-specific manner.
Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Sarmento Leite, 500, Porto Alegre, RS, CEP 90050-170, Brazil. tiflosoles@yahoo.com.br
Marcelo Alves
MA
de Souza
Raphael Escorsim
RE
Szawka
Lígia Aline
LA
Centenaro
Luisa Amália
LA
Diehl
Aldo Bolten
AB
Lucion
D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal; D002851:Chromatography, High Pressure Liquid; D003345:Corticosterone / Q000097:blood; D004563:Electrochemistry; D005260:Female; D006801:Humans; D008297:Male; D008425:Maternal Behavior / Q000523:psychology; D008734:Methoxyhydroxyphenylglycol / Q000378:metabolism; D009043:Motor Activity; D009638:Norepinephrine; D009812:Odorants; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D017208:Rats, Wistar; D012149:Restraint, Physical / Q000379:methods; D012727:Sex Characteristics; D012903:Smell / Q000502:physiology*; D013315:Stress, Psychological / Q000097:blood / Q000209:etiology* / Q000523:psychology
D008734:Methoxyhydroxyphenylglycol; D003345:Corticosterone; D009638:Norepinephrine