What’s cooking in physiology research: “Towards safer births”

Shalini Kumar

On Tuesday morning I was sitting at my desk working on this article, struggling to put my research into comprehensible sentences by avoiding any scientific jargon that would drive my potential reader(s) away. That was when I came across this cartoon. A pregnant woman is putting on a brave face, saying that her pregnancy is going “just fine”, when the truth is nowhere close! Her thought bubble precisely sums up everything a pregnant woman is most likely to face during those precious nine months of her pregnancy. Although I was spared the varicose veins, thank God!

From the moment her baby is conceived, a woman’s life is completely altered, physically, mentally and emotionally. The physical changes are not only the obvious ones, like swelling breasts and belly. There are less visible changes also occuring, inside the body. For example, pregnancy causes physical changes in the brain, whose nerve cells (neurons) undergo a degree of plasticity unique to this time of a woman’s life. The brain changes in response to hormones secreted during pregnancy, initiating adaptations necessary to maintain a healthy pregnancy.

My research focuses on understanding how the brain regulates the process of birth. This comes down to a close study of the posterior pituitary gland, found on the underside of our brain. The posterior pituitary gland secretes a hormone called oxytocin.  Commonly known as the “love-hormone”, oxytocin is crucial for successful labour and lactation.

Oxytocin is produced by neurons in our brain. When these neurons are excited, they stimulate the posterior pituitary gland to secrete oxytocin into the blood, triggering uterine contractions during birth, and milk ejection during suckling. Labour and breastfeeding produce a unique physiological state of neuronal super-excitation, and secretion of large pulses of oxytocin.

The questions I am trying to answer through my PhD are:

• what triggers this excitation of oxytocin neurons?
• how do they know when to start firing?

From previous experiments, we believe that this excitation could be facilitated by another hormone (also secreted by neurons) called kisspeptin. We think kisspeptin signals might increase the sensitivity of oxytocin neurons, making the oxytocin neurons highly sensitive, towards the end of pregnancy, to signals from the uterus, and priming the mother’s body for labour.

Eight out of every 100 children born in New Zealand are preterm, and these infants are at increased risk of debilitating health consequences throughout their lives. Preterm birth happens when the oxytocin neurons are activated much too early. Hence, understanding how oxytocin is regulated is critical to understanding what might go wrong in preterm births.

I work on mice as an animal model to try to tease out the neural circuitry involved in birth as this knowledge would better equip us to address the issue of preterm births and perhaps even develop possible interventions to delay delivery to give preterm infants a better start in life.

Apart from my research, I enjoy honing my creative skills whenever I can. I love to paint and try out new arts and crafts, but with my studies and being a mum of a toddler, making time for such interests is quite challenging. Thus  when I heard of the recent “Bake your thesis”event organised by the University of Otago Graduate Research School, I was all for it. It was a rare opportunity to be creative in expressing my scientific journey. My cake represents a microscopic image of the mouse brain showing oxytocin neurons (in green) with kisspeptin nerve fibers (in pink) around it. I also wanted to highlight the fact that my research was in the interest of leading “towards safer births”, hence the happy mother and baby seated on the cake.

---

Shalini S. Kumar is a second year PhD student supervised by Professor Colin Brown (@OxyPressinGuy) and Dr Rachael Augustine, studying in the Centre for Neuroendocrinology and Department of Physiology at the Otago School of Medical Sciences (@CneOtago).

Read about what’s cooking in other Bake Your Thesis research:

• in pharmacy: “A Wave of Pills”
• in genetics: “I incyst you try some”
• in physiology: “Towards Safer Births”
• in forensic anthropology: skull and cakebones
• in human nutrition: How to bake a healthy chocolate brownie and What’s cooking in human nutrition?