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From 5 to 22 months of age, cognitive and emotional responses of nulliparous, primiparous, and multiparous rats were assessed using a dry land maze (DLM) and an elevated plus-maze (EPM) at 4-month intervals. Parous rats exhibited improved spatial memory in the probe and competitive versions of the DLM, and more exploration in the EPM and a novel stimulus test relative to nulliparous females. The nulliparous females, however, outperformed parous rats during the DLM visual cue test at 17 months of age. At 23 months, no differences in stressed corticosterone levels or Golgi-stained hippocampal neurons were observed. Thus, cognitive and emotional modifications were observed in parous rats; the neurobiological mechanisms for these enduring effects, however, remain to be identified.

Artemis, the Greek goddess of childbirth and of the hunt (which are complementary activities in a female's repertoire) serves as an apt figurehead for the multiple exertions that define motherhood. A new mother is faced with many novel and unforgiving challenges (1), and any improvements in the behaviours on which she herself relies for sustenance would be advantageous for her, for her offspring, and for her genetic legacy. Change and enhancements to her existing behavioural set, preceded by modifications in neural regulation, would be advantageous and, hence, selected for. Organisms continue to develop and change throughout their lives, shaped by the external demands of the diverse environments in which they exist, by the inherent neurobiological factors that evolved to regulate their physiology and behaviour, and through the exquisitely precise interactions between environment and physiology that determine survival. Indeed, contrary to much thought, brain development is not confined merely to the neonatal-pubertal period of life when initial growth and systems elaboration are occurring. In particular, the adult female brain is significantly modified, and reorganised in some examples, in surprisingly rapid fashion, as during the oestrous cycle and after exposure to gonadal steroids.There has been growing attention devoted to the interesting neural plasticity (we define this phrase later on) intrinsic to the female's reproductive life, particularly endocrine-neurone relations that may be unique to pregnancy (parity ⁄ parous states), the postpartum period, and the reciprocity of maternal-infant stimuli. Such factors raise a bevy of fascinating questions. What might such changes mean for the female's behaviour subsequent to the reproductive events themselves? How might they be related to the quality of care she provides her infants, or the likelihood she will be abusive? Are there neural predictors of stress or anxiety sensitivity or resolve that may be expressed? Are there long-lasting and pervasive alterations in the female that accompany the events of pregnancy and that influence behavioural states (including learning and memory, foraging, stress responsiveness, etc.) throughout her life? In this review, we are interested in the dynamic female brain and its natural changes that accompany reproduction and that regulate the female's pup-directed, social and ancillary behaviours.Closely observing the basic interactions between a mother and her offspring, rat as well as human, inspired us to ask the simple question about the onset of motherhood and its requirements for Journal of NeuroendocrinologyCorrespondence to: Craig H. Kinsley, Department of Psychology-Center for Neuroscience, University of Richmond, 28 Westhampton Way, Richmond, VA 23173, USA (e-mail: ckinsley@ richmond.edu).As a female transitions into motherhood, many neurobiological adaptations are required to meet the demands presented by her offspring. In addition to the traditional maternal responses (e.g. crouching, nursing, retrieving, grooming), our...