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Professor Simone Meddle on hormones and animal behaviour

Birds turning down their stress responses during breeding season, rats enjoying being tickled, and time-travelling.

Simone Meddle
Simone Meddle

Professor Simone Meddle is Personal Chair of Behavioural Neuroendocrinology at the Roslin Institute. In this interview, she talks about her work on investigating environmental effects on the brain and hormones of birds, animal welfare, and her passion for being a scientist.

Could you describe your work in a nutshell?

I’m a behavioural neuroendocrinologist meaning I study brains, behaviour and hormones. More specifically, I want to further understand how the environment affects the brain and the secretion of hormones to change behaviour.

As a neuroscientist I study the brains of a variety of animals, from quail, rats, pigs, sheep and chickens to songbirds breeding in Alaska. I tickle rats to increase a positive emotional state and investigate the effects of this environmental enrichment on the brain.

I also study how wild birds respond to stressful environmental conditions and adapt their stress response and physiology when breeding in capricious environments such as the Arctic. I also study the regulation of appetite, maternal behaviour and the effects of early life stress in poultry.

How did you become interested in these fields of research?

I have been interested in birds for as long as I can remember! For example, when I was 7 years old I would lie in the long grass in a field behind my parents’ house and watch skylarks with my binoculars. I’ve always been fascinated with nature, ecological webs and understanding why animals behave in certain ways.

Since my postgraduate studies in Bristol, I continue my deep interest in understanding the neural mechanisms regulating seasonal breeding. It is quite a broad range of interest I guess!

Could you tell me about a real world application of your work?

One of my research projects is looking at how climate change affects birds breeding in the Arctic. We have already documented that some migratory song bird species, such as the white crowned sparrow, are breeding further north than they used to. In collaboration with scientists at UC Davis we are documenting what’s happening to them as they experience more extreme weather events during breeding.

We also investigate the effect of early life stress on behaviour and the neural networks in the brain that control social behaviour in later life.  This is important particularly given the housing conditions for some young animals. We are currently looking at the effects of early life stress in chicks in relation to the feeding circuits in the brain that regulate appetite. I want to make a difference and use our discoveries to improve animal and human lives.

Could you tell me about a study you’re working on now?

I’ve got about six in my head at the moment! We are currently working on understanding the photoreceptors in the brain of birds that regulate breeding and also the molecular mechanisms regulating seasonal “circannual” rhythms of physiology and fertility in sheep.

I have also worked in the high arctic in Greenland studying the birds breeding there and it’s really fascinating, as during breeding they pretty much turn their stress response off so that when they have chicks they have no secretion of stress hormones. If we can understand how these birds are able to do that, we might be able to come up with ways to do that in other animals and humans - I’d definitely like to turn my stress response off at certain times, wouldn’t you?!

Looking forward, what is really exciting is that we’ve sequenced the entire genetic makeup of resident and migratory white crowned sparrows, and we have recently completed some RNA sequencing studies to identify genes involved in the mechanisms underlying stress hormone physiology.

That is so interesting! Could you tell me about one of your projects on rats too?

Of course! Understanding behaviour in rats really interests me, mainly in relation to positive welfare and emotional state. Did you know that when you tickle rats (they like to be tickled!) they emit ultrasonic vocalizations? i.e. they laugh! We are mapping the brain regions involved in the response to tickling, examining the differences between males and females and investigating whether it can be used as a means to improve the lives of rodents in laboratories. Interestingly, mice don’t like to be tickled like rats do!

I also study maternal behaviour in rats, investigating the changes in the brain that occur after birth. Your brain after you’ve given birth is not the same as the brain you had before you got pregnant - it kind of gets adapted so that a whole suite of parental behaviour is displayed. It’s true for rats but you would presume it is similar for other animals and people too.

Do you have a favourite project from your time here?

It has to be all the field work I’ve been involved with. Field work is a large part of my work as I study stress physiology and adaptations to the environment. We have a National Science Foundation grant with collaborators from UC Davis and I work in the field in the Arctic on the birds that breed up there. I have been doing field work for over 20 years and it is my favourite bit of science. We have made some impactful findings especially in relation to reporting the effects of climate change.

Can you tell me about a challenge that you’ve experienced during your research?

Other than being out doing field work with Grizzly bears wandering around?!! A major challenge is getting funding for all of my exciting research ideas. Science is all about discovery and making a difference and the challenge is convincing reviewers and funders that our studies are the ones to fund. Another challenge I face is not having enough hours in the day to do everything I want to do! I have many ideas and lots of projects but it’s getting the time and the money to do them all.

How did you become a scientist?

I’ve always wanted to know ‘why?’ and to understand the things happening around me. Since I was a small child I’ve been interested in biology. I have always been really curious about natural history and the behaviour of animals especially insects and birds.

And finally, if you weren’t a scientist, what would you be?

I can’t imagine not being a scientist! I can’t imagine not having this job, I love it, I really do! Every day is different from the previous and I love the variety. I have been really fortunate to work with amazing scientists from all over the world and appreciate those friendships and collaborations. I also really enjoy inspiring and mentoring the students I teach.

Hmm, what would I do if I weren’t a scientist? Can it be something completely random? I’d love to be a time traveller like Dr Who and travel back to the Triassic Period to see the dinosaurs and flying reptiles, especially pterodactyls. Imagine that? Wouldn’t that be so exciting to see those pterosaurs soaring high in the sky!

I love being creative in the lab, inventing and changing protocols and also really enjoy doing the same thing in the kitchen at home creating new recipes. So I guess I could have been a pretty good chef making people happy by creating delicious plates of food!

Related links

Rats associate a smell with a positive experience

The animal feelgood factor

Animal welfare on the Easter Bush Campus