New Publication – An explant approach to studying fat tissue function in wild animals

Adult male grey seal hauled out on a rocky seashore. Even in wild conditions, the PHATS team is bringing cell culture into the field!

Link to article: https://www.nature.com/articles/s41598-017-06037-x

Or read the summary here on this site.

Behaviour 2017’s fantastic closing dinner party, complete with a live band featuring 6 ukuleles!

I have now returned from an incredibly successful week at Behaviour 2017 (link), and what a spectacular conference it was! The sheer variety of science that people were talking about was incredible and inspiring, plus I got a great response to both my symposium talk on seal oxytocin and the poster I presented on aggression. I meet so many wonderful people, heard lots of interesting talks and I even managed to avoid getting roasted in the blazing Portuguese sun! I had never previously been to a behaviour conference of any kind, but this one has really encouraged me to keep an eye out for future ASAB meetings to present at. Huge thanks to the lovely people working as part of the SoHaPi research group for inviting me to speak at your symposium, I look forward to meeting up with you all in the future!

Taking the stage at Behaviour 2017 to talk about my work on oxytocin in wild seals

More good news was waiting for me when I arrived home from Portugal; our PHATS team leader, Dr Kimberley Bennett, let us know that the first paper the PHATS team have worked on was coming out at last! This paper details our work investigating whether an explant approach (basically blobs of many living cells) would work for culturing fat (or adipose) cells collected from wild animal species in field conditions. Additionally, we wanted to know whether we could manipulate the explants during culture to

100mg explants of adipose tissue weighed out and ready for transfer to culture plates for their 24 hour exposures to different treatments on the Isle of May, Scotland.

uncover the physiological consequences of changes in the nutrients or hormones the cells have access to. We found we could not only keep our cells alive once collected from wild seals on the coast of Scotland, but once transported back to the lab we could culture the cell explants for at least 24 hours. During this time we could expose the adipose cells to different treatments, such as high glucose concentrations in the cell culture media (the sugary, salty goo that cells are suspended in during culture to keep them alive) or difference hormone additions, such as hydrocortisone. We found significant differences in the metabolic profiles of adipose cells given different treatments, demonstrating this technique could be used to test the responses of wild animal tissue to a variety of substrates an individual may physiologically generate, or be exposed to.

Studying wildlife physiology is always challenging because collecting samples is tricky, typically giving small samples sizes in less than ideal conditions for complex labwork. However our work to bring cell culture techniques to the wild regions of Scotland shows that even difficult processes like cell culture, which require sterile conditions, aseptic technique and specialised equipment, are possible with thought and preparation beforehand. Studying cell function in wild animals is important as how different tissues function in response to different environmental challenges will impact on how individuals survive. Fat tissue is especially crucial for survival as it represents the energy stores animals have to rely on when conditions are tough, and also helps keep individuals warm in cold environments. By understanding how fat tissue functions, we can better understand why different species in changing environments can either adapt to meet new energetic challenges or be overwhelmed by them.

Even in muddy, windy or wet conditions, cell culture experiments can be possible if you are careful! (grey seal mothers and pups on the Isle of May, Scotland)

Speaking of ‘the wild regions of Scotland’, it’s that time of year when I start prepping all the field equipment for the PHATS team’s annual research trip to the Isle of May grey seal breeding colony, off the east coast of Scotland. Join us here for our fieldwork blog, bringing you all the adventures we have running a tissue culture lab on an island full of seals. We are scheduled to leave in late October, and will stay on the island studying the seals for about 2 months, heading home just in time for Christmas (hopefully!). I’ve also got two more conferences to attend before I go off into the field, one in September in Nottingham, UK with the British Society for Neuroendocrinology and one in October in Halifax, Canada with the Society for Marine Mammalogy. If you are going to either and want to say hello I look forward to meeting you there!

Weaned grey seal pups occupying the path down to Kirkhaven harbour on the Isle of May, Scotland

New Publication – IV oxytocin causes pro-social behaviour in seals

Grey seals on the Isle of May, Scotland. Staying together is important for mother-infant pairs, especially on a dangerous seal colony.

Link to article: http://rspb.royalsocietypublishing.org/content/284/1855/20170554

Or read the summary here on this site.

This week has turned out to be a hectic but good one, I’ve returned from the University of Liege just in time for my next paper to be published in the Proceedings of the Royal Society B. The paper comes from the research in my NERC funded PhD with the Sea Mammal Research Unit, University of St Andrews on the hormone oxytocin and its impacts on social and maternal behaviour, rather than the pollutant research I’m currently doing with the PHATS team. Like much of my work, the study was done with weaned grey seal pups on the Isle of May, and involved giving the seals specially designed doses of oxytocin to see what (if any) social behaviours the hormone affected.

There have been lots of studies that show certain behaviours are linked to oxytocin concentrations (including some of my own grey seal work!), but the problem with correlations is that you have no idea which side of the relationship is driving things. For example, it would be impossible to tell using only correlations whether increased social behaviours are causing high oxytocin levels, or high oxytocin levels are triggering more social behaviours. Understanding causality in such hormone-behaviour relationships is important so you can identify the ‘cause’ and the ‘effect’ within the correlation. It can be difficult to do outside of laboratory settings however, as the only way to test for causality is to either increase the hormone’s concentration in an individual via manipulations or knock out the functionality of the hormone using antagonists. Due to these difficulties, there is only one study (apart from the one I published today) that has ever given oxytocin to wild individuals, and while they did find changes in pro-social behaviours they had no prior knowledge of the natural oxytocin-behaviour systems in their study animals.

We know high oxytocin grey seal mothers stay closer to their pups, but does the hormone cause the behaviour or does being near to their pup for more time cause greater oxytocin release?

In our study we were testing whether oxytocin triggers individuals to stay close to each other, as we know from grey seal mothers that the higher their oxytocin concentrations, the more time they spend close to their pups. We gave oxytocin and saline (control) treatments to weaned grey seals that had never previously met, and recorded their behaviours after the treatments. We found that oxytocin not only triggered individuals that had never met before to spend more time together, but also reduced aggression between the two and the amount the seals investigated each other, an indication of familiarity. This makes our study the first to verify a naturally existing oxytocin-behaviour relationship in wild individuals, which is very exciting. Studies like this have been done in captivity using domestic, laboratory or zoo animals but it’s crucial to study behaviour and physiology in natural settings with wild individuals, as no matter how hard you try you will never truly re-create all the complex aspects of wild environments in a captive setting.

Weaned grey seal pups associating on the Isle of May, Scotland

The treatments were all given intravenously (IV), as the more common, intranasal route of oxytocin manipulation was not possible with the weaned seal pups; they can close their nostrils and hold their breath for a long time! The success of this route of administering the manipulation means that other animal species, that may not be suitable for intranasal manipulations, could potentially have similar studies done on them in the future to help us understand more about oxytocin’s important role in bonding and behaviour. We also spent considerable effort designing the oxytocin dose given to the seals to be as low as possible while still having a behavioural affect. Many doses used in the scientific literature are much higher than natural concentrations, and there are concerns that generating high levels in study individuals could trigger behaviours that would never naturally happen, or have unexpected, and unwanted, side effects.

Weaned grey seal pups having a disagreement on the Isle of May. Reduction of aggression between familiar individuals happens naturally without oxytocin release in seals, but manipulations also trigger this behavioural change with seals that are complete strangers.

Despite the effort we went to in replicating natural oxytocin concentrations as much as possible for our study, the treatments still triggered some behaviours that are not naturally correlated to oxytocin release in seals. Low aggression and reduction of investigative behaviours are indications that seals recognise each other, and naturally occur after several days of living together, independently of oxytocin release. The behavioural changes in our study seals also unexpectedly persisted for several days, long after the dose would have been metabolised and broken down in the bloodstream. These unexpected effects show that we still have a lot to learn about oxytocin’s role in the formation and maintenance of social and parental bonds. If the hormone is going to be used to safely and successfully treat human psychological conditions such as schizophrenia, autism spectrum disorders and post traumatic stress disorder (and there have already been clinical oxytocin trials for such conditions in human subjects), then more research is needed into the powerful effects oxytocin can have on our behaviour and neurobiology.

Weaned grey seal pup on the Isle of May.

New Publication – Individual aggression in young grey seals

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Working out whether to be nasty or nice to your neighbors is crucial for many species!

Link to article: http://onlinelibrary.wiley.com/doi/10.1111/mms.12367/full

Or read the summary here on this site.

Its that time of year when lots of people at my lab in St Andrews are getting ready for the grey seal breeding season on the Isle of May (IOM16), an important chance for many different projects studying everything from behaviour to physiology to get crucial data or samples. Logistically, getting all the supplies for the science the PHATS team needs to do in the next two months is quite a challenge and I’m currently packing and checking equipment off all sorts of lists to ensure we’ve got everything. Everything for the tissue culture work needs to be sterilised here on the mainland and packaged up carefully so we can get it out to the island in one piece, taking PCR hoods and incubators out on boats can be interesting but we managed fine last year so I’m sure it will all work this year too. We should be heading out to the island in the last week of October (as long as the weather plays ball), and I’ll start posting regular blog updates about what’s happening once we are in the field.

In amongst the ‘organised chaos’ of all the packing, it was great to see that one of my new papers was finally available online for people to read. The work was done as part of my PhD and happened on the Isle of May too, although this study was a purely behavioural one. Its always a relief to get a piece of work published, the process can be long and arduous but ultimately getting your science out there for other people to read is what research is all about. So why study aggression, and why on the seals on the Isle of May? Read on…

Aggression is a vital aspect of an individual’s behaviour in the majority of animal species trying to live in the wild. Being aggressive enables individuals to take things from others that they need to survive or reproduce, such as mates, good quality habitat to live in or things to eat and drink. Conversely, being aggressive also means you can defend yourself, your offspring or members of your social group from attack, or protect your territory or food resources from attack. The ability to gain the best resources to live on, and keep hold of them so you and your offspring benefit from them, is therefore an important one. But as aggression can have high negative costs, such as injury or even death, striking the balance between individuals that aren’t push overs, but don’t get into too much conflict is an interesting evolutionary challenge all species face. There is huge variation in how aggressive different individuals are, and while some of this variation can be attributed to true psychological differences, which only exist in each individual’s head, we wanted to know to what extent physiological or environmental factors impacted on how aggressive individuals are.

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Aggression can enable individuals to protect things that are valuable to them, like their offspring…. (grey seal mothers and pups on the Isle of May, 2015)
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…or aggression can help you fight for the things you need, like access to the lady seals! (male grey seals fighting for access to females, Isle of May, 2011)

There have been many studies on the sources of individual aggression in a variety of species, from humans to insects. However there are not many studies investigating how aggressiveness in individuals develops in the wild (the ontogeny of a trait). As I had previously designed and carried out research documenting aggressive behaviour in the weaned grey seal pups on the Isle of May, it was an ideal place to try and find out more about the individual factors that influence how aggressive individuals are towards each other. We found that pups raised on crowded areas of the colony were more aggressive than pups from areas with few seals, and that physical characteristics (sex and size) also influence how aggressive individuals were. Males got more aggressive the bigger they were, but female size and aggression showed a non-linear relationship, meaning even a small female seal could still be very aggressive towards others!

The social environment you are raised in has been shown to have lifelong impacts on your behaviour, so it would be great to determine whether these aggressive pups from high density areas of the breeding colony stayed that way throughout their entire lives, or whether other factors take over as the individual grows up. The same is true for males and their body size, are these males only aggressive when they are large, and do they become more timid as they lose mass when using up their fat reserves during the moult or breeding season? Lots of questions still to answer, but this study highlights how a few individual features can influence behaviour, and indicates these variables are worth investigating in future work.