Early‐life stress affects behavioral and neurochemical parameters differently in male and female juvenile Wistar rats

Abstract

Infant rats rapidly learn to identify and prefer maternal odor naturally within the nest (Leon, 1992). Olfaction is the main sensory system used for infant-mother interaction in rodents (Weber & Olsson, 2008). Pups without the ability to smell cannot develop properly because they fail to nipple attach, becoming malnourished (Landers & Sullivan, 2012; Opendak, Gould, & Sullivan, 2017; Weber & Olsson, 2008). It has been shown that neonatal handling (a brief, repeated separation of pups from the mother) reduces the approach behavior toward maternal odor in female pups, although this was not observed in males (Raineki, De Souza, & Szawka, 2009). Previous studies from our group have also shown sex-specific effects of neonatal handling on learning in adulthood (Noschang,