Single or multiple reproductive experiences attenuate neurobehavioral stress and fear responses in the female rat.

The female brain is a dynamic structure, which expresses its plasticity most readily following reproductive experience (RE). In Experiment 1, we generated nulliparous (NP), primiparous (PP), and multiparous (MP) females (none, one, and two litters, respectively). Two weeks following the weaning of the first/second six-pup litters, the age-matched MP and PP and the non-pup-exposed NP animals were subjected to a 60-min restraint stress paradigm (enclosure in a Plexiglas restraint tube).