Guest Blog: Behaviour, Hormones & Other Adventures to the ‘Dark Side’

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My study site and hide on the island of North Rona in Scotland.

Our first guest blogger comes to us from our colleague and former Durham University student, Dr Kelly J Robinson – (Research Blog  – Twitter Feed)

Time flies. It seems there never was a truer statement than when I think back over my meandering path into the world of behavioural physiology and realise, to my surprise, I’ve been here for almost 10 years. Graduating from my undergrad zoology degree at Durham University in 2008, I was faced with the ‘what now?’ question that daunts so many once the gowns come off, but I was lucky. I got to spend a year of my undergraduate degree in an industrial placement (which I highly recommend!) studying farm animal and wildlife welfare. Thanks to this experience, I at least knew the types of science I wanted to steer towards in the coming years, even if I didn’t know how to actually make aspirations into realities. Studying animal behaviour had long been in my hopes and dreams, ever since staring wide eyed at the TV while Sir David guided me through the ‘Trials of Life’. But after a year actually working in animal science, my research interests spiralled wider to include an avenue I’d previously not given much serious thought… physiology.

Behaviour and physiology are inextricably linked and, like the chicken and the egg, it can be hard to determine which comes first and which follows. Physiological systems can control or moderate the behaviours individuals’ exhibit, and any behaviour performed, combined with the responses of other creatures to those behaviours, impacts on an individual’s physiology. In that first year of working in animal research, it became clear to me that while studying animal behaviour was enlightening, important and fascinating, linking your research to aspects of an organism’s physiology added another dimension to your research. By investigating both, you can gain insights that never would have been possible by only focusing on one of these two aspects of animal science. With this interest in studying both outwardly expressed behaviour and inwardly fluctuating physiology, I started on a path that led to my PhD research at the University of St Andrews, on the neuropeptide hormone oxytocin and its role in maternal and social behaviour.

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Grey seal mother – pup pair on North Rona

Oxytocin is a hormone that acts both in circulation and in the brain. Its functions range from triggering muscular contractions during birth to forming social bonds between associates. It seems to play a vital role in linking the physical process of birth to forming strong mother-infant bonds and promoting good quality maternal care in all mammal species studied to date. There have been behavioural studies (e.g. Kovacs 1987) documenting the maternal behaviour phocid seals display towards their pups, and many demonstrate how variable the quality of maternal care exhibited by individual mothers can be. Phocid seals have some of the shortest dependant periods (the time infants spend nursing from their mothers) of all mammals. For example, grey seals (Halichoerus grypus) only spend about 18 days looking after their pups before weaning and leaving them to fend for themselves. Given the short time frame mothers have to look after their pups, why isn’t there selection pressure to ensure all mothers perform high quality maternal care, to give their pups the best chance of surviving their first year? I thought that by investigating oxytocin concentrations in grey seal mothers we could gain some insight into why there was so much variation in maternal care quality in this species.

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For grey seals, being a ‘good mother’ is important for pup survival, pups need feeding and protecting from threats, including other mothers on the crowded colony.

At the start of the project, we had to try and understand the naturally existing oxytocin system in grey seals. To do this we first had to validate a detection method for analysing oxytocin in grey seal samples as the hormone had never been studied in any marine mammal species and only a few researchers had detected it in wild animals. Once we knew we could rely on our analysis technique, we began to document the naturally existing relationships between oxytocin and maternal behaviour in grey seals by studying wild breeding colonies in Scotland. We found that mothers with higher oxytocin concentrations spent significantly more time in close proximity to their pups on a breeding colony . Keeping close to your pup on a busy, dangerous colony reduces the likelihood of mother-pup separation, which frequently leads to pup starvation, the largest cause of pup death during the breeding season. It had long been theorised that oxytocin promotes proximity seeking between mammalian mothers and infants, and our study now showed that a relationship did exist between the behaviour and the hormone.

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Grey seal mother keeping her newborn pup close on the Isle of May

 

While detecting naturally existing hormone-behaviour correlations does indicate the two are somehow linked, it does not tell you the causal nature of the relationship, i.e. is the behaviour causing hormonal changes or is the hormone causing behavioural changes? To address this, we designed a series of manipulation experiments with wild, newly weaned grey seals to determine exactly what behaviours were affected by elevated oxytocin levels. Weaned seals given oxytocin spent more time in close proximity to other seals than those given saline control treatments, demonstrating that the hormone is capable of triggering this behaviour. However, the hormone manipulations also triggered other pro-social behaviours like low aggression rates. This was unexpected, as we had previously run a set of recognition studies on weaned grey seals that showed while they can recognise other seals and reduce their aggression to familiar individuals, oxytocin is not involved in this process. The behavioural changes the oxytocin treatments caused also persisted several days, much longer than anticipated, as the dose given was designed to be so low that it would soon be metabolised within two hours. Our work therefore highlighted how the behavioural outcomes of oxytocin manipulations can be unpredictable, and that current research and medical trials to use oxytocin to treat human psychological conditions need to explore potential dose effects and unexpected changes in behaviour.

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Weaned grey seals on the Isle of May, with the seal on the left exhibiting an aggressive behaviour known as ‘flippering’

 

With the end of my PhD in 2014 I started a Post Doc at the University of St Andrews which focuses on the physiology side of seal biology, and since then I find myself going further to the ‘dark side’ of molecular biology, learning cell culture and pollutant detection lab skills! But I am still keeping up my behavioural research in my ‘spare time’, and I will be giving a talk during one of the Monday symposiums at the 2017 Behaviour conference in Portugal this summer. If you would like to know more about my research on oxytocin and behaviour you can read more about it on my research website, https://kellyrobinsonscience.wordpress.com/. This site is also the home of my fieldwork blog, about my adventures to the Isle of May seal colony where I will join Courtney, Sean and the latest members of the SealBehaviour team in late 2017 to study the grey seals once again. The field season is always the highlight of the year, so I’m looking forward to it!

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Making friends during the field season on the Isle of May!

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