| dc.description.abstract | Maternal behaviour during the peri-partum period, albeit in differing forms, can be
observed in all mammals, thus it must serve an important evolutionary purpose in
enabling the successful raising of offspring. Maternal behaviour is comprised of a
large suite of behaviours; in rodents these are generally defined as lactation, pup
retrieval, maternal aggression and pup grooming. The maternal behaviour circuitry
involves many brain regions including the hypothalamus and the limbic system
which work together to regulate the motor, motivational and emotional demands of
the lactation period. The main aim of this thesis is to understand how different
neuromodulators, specifically oxytocin (OXT), vasopressin (AVP), allopregnanolone
(AP) and GABA, influence the expression of maternal behaviour, especially
maternal aggression, and where in the brain they act to control this.
Maternal aggression in rats changes dramatically throughout pregnancy,
parturition and lactation. This expression is highly influenced by pups and during
early lactation, pup cues are essential in maintaining it. Towards the end of lactation
pup cues appear to result in the down regulation of maternal aggression. The
maternal aggression circuitry is highly complex and involves many of the brain
regions highlighted to be involved in maternal behaviour. The neuropeptides, OXT
and AVP, are observed to have significant changes in their systems that correlate
with maternal aggression, specifically within the BnST and PVN. This leads to the
proposal they work oppositely to control maternal aggression by regulating fear and
anxiety in the lactating rat. There is also evidence the OXT system mediates the
motor output of maternal aggression. AP and GABA are also important in maternal
behaviour, especially in relation to fear; whether this in context with OXT to enable
maternal aggression or if they are a back up mechanism for OXT secretion
malfunctioning remains to be determined.
By understanding the complex maternal behaviour neural circuitry and how
neuromodulators work to control it, enables the development of potential therapies
for disorders a woman may experience during the peri-partum period. Prevention of
these disorders is not only beneficial to the mother and her immediate family but is
also crucial for her offspring’s development in prevention of adulthood disorders
stemming from their childhood experience which can impact their own paternal or
maternal care ability. | en |
