Overview
This lecture may not be of immediate personal concern to some of you, but hopefully you will all at some time experience the joys of parenthood. This is how my personal interest in the topic arose.
When my son was born I began to wonder how the interaction between mother and child was controlled. And this set off a research programme concerned with factors that control the defining mammalian behavioural pattern - suckling.
The lecture begins with a look at the psychological changes that occur during human pregnancy. I draw your attention to this material because it seems to me that this area provides a rich resource of research questions that could be tackled in a third year project.
But in order to understand the biology of parenting we need to resort to an animal model, and once again the humble lab rat comes to the rescue. In fact, maternal behaviour in the rat is remarkably robust and reliable. By this I mean that it is really very easy to observe these behaviours under laboratory conditions. We look at two behaviours, retrieving and suckling, that can be elicited very easily. How unlike some of the behaviours that we try to study in the lab!
We then move on to ask questions about the role of hormones in the initiation of maternal behaviours. Three candidates - estrogen, progesterone and prolactin - have received extensive investigation by Jay Rosenblatt and his co-workers in an elegant series of experiments. Although these studies suggest that maternal behaviour is facilitated by a decline in progesterone, and an increase in estrogen levels, they do not account for the rapid onset of maternal behaviour immediately after parturition.
Recent work with central injection of oxytocin is described to illustrate how this research field is still revealing answers.
Finally we will look at factors that control the maintenance of maternal behaviours in order to answer the questions "Do pups maintain maternal behavior by promoting the release of hormones in their mother?" or "Do pups simply provide a particular type of sensory stimulation?