Hi, I'm Professor Zoe Donaldson and I'm a neuroscientist at the University of Colorado Boulder. But I didn't actually start my career as a Neuroscientist. I started my career in the Jungles of Nicaragua as a behavioral ecologist. I was interested in these organisms which you may know as daddy long legs or harvest men. In this particular species, it would aggregate on these spiny palm trees during the day and then go off and try to find food on their own at night. Every day they would find a new aggregation site. I was interested in the questions of why and how they find these sites. But as I was carrying out this research, I realized that what I was ultimately interested in was less the question of how, but what drove these animals to seek other members of their species. I realized that in order to answer that question that I needed to become a neuroscientist. Unsurprisingly I present myself to you today as a social neuroscientist. What I'm going to tell you is that as social beings, we, as humans need social interaction, just like we need food and water in order to survive. You've heard today about loneliness as the deprivation state that results when you don't get enough interaction. This is akin to thirst or to hunger, and Dr. Park went into great detail about some of the things that matter with respect to loneliness and it contextual sense and otherwise. What I'm going to tell you is that while we understand relatively well how thirst or hunger are encoded within the brain, we know far less about how loneliness and the drive to be with other individuals is ultimately encoded within the brain. One thing we do know is that loneliness is not alleviated by simply being around other individuals and this may be something that you're becoming very familiar with as you move away from your family and onto a college campus. You're surrounded by other students like you, but you may not have formed the bonds that will ultimately become the basis of your social world here. What this means is that the emotional content of the relationships that we form is really important and you probably know this at a fundamental level because we use social relationships in a variety of different ways. When we're faced with a traumatic situation, our first reaction is typically to reach out to someone who can console us and help us through that time. This active consolation has more than just emotional consequences that can actually help to return your physiological stress response back to baseline levels. The cumulative effects of having these strong and supportive social relationships, is that when you face something, some malady or insults your health, whether it be surgery, cancer, cardiovascular disease or diabetes or mental illness, you recovery from these events is facilitated if you are surrounded by a strong and supportive social network. This begs the question though, what happens when we can't reach out to these sources of social support in the ways that we typically do. This is something that's become incredibly apparent to us in terms of the ways in which lock down and other things that have occurred during the Covid-19 pandemic, have impacted our mental health. This is something that you might also be acutely familiar with at this point in your life when you move away from your family and your high school friends, and you now don't have access to them in the same way that you did. You can't seek out the consolation, the fun, and the happiness that they could bring you in the same way that you did before you moved here. I'm particularly interested in understanding this drive within the context of romantic relationships and that's because I think if you're going to study something, you should study it from the perspective of one of the most powerful examples that we have and in humans, romantic relationships have shaped our art, our literature, arguably have caused wars in the past, so this is one of the most powerful relationships or bonds that we're capable of forming. There are many advantages to studying these types of bonds in humans. You can ask people, how much do you love your partner, how much do you miss them when they're away. But as a neuroscientist, what we can't do in humans is we can't really get at what is happening in the brain when people fall in love. In particular, as of yet, I can't put tiny microscopes into a human brain to peer at and watch cells within the brain as they're being activated by a partner. What this means is that in my laboratory, we need another species that exhibits many of these behaviors and can serve as a proxy for this type of human behavior. What I'm going to tell you about today is a monogamous rodent species. These are called prairie voles and they live within the prairie states at the US, including the eastern portions of Colorado. In the wild, a male and a female praire vole will meet, they'll mate, they'll establish a burrow and they'll take care of their offspring together. This is in contrast to the majority of mammalian species, including laboratory mice and rats, when the male and the female will mate and then the female will go off and she'll raise the offspring on her own and subsequent litters are likely to be sired by a different father. Prairie voles like us form these, what we would call pair bonds between mates, and this provides us with a behavioral substrate that we can begin to look at in order to identify sort of the drive that exists that leads these animals to seek out their partner. Now ultimately, if we're interested in what happens when you can't fulfill that drive to be with your partner. This winds up being a really challenging question because you're essentially saying, how do you study the absence of a partner? How can you study something that isn't there? But what I like about science is that it's ultimately creative and so what I'm going to show you today is one of the creative ways in which my laboratory actually studies the absence of a partner. In order to begin, we need to be able to study the presence of a partner and the drive to be with that individual. For that, we take advantage of a long history of neuroscience research. We specifically ask the animals to work to get access to their partner. Within my lab, the way that we do this as we ask an animal to press a lever and as a reward, they get to go and they get to huddle with their partner. This video that you're seeing here, what you'll see is that the test animal, a light comes on, a lever comes out, it presses that lever and now a door opens. What you saw was that the animal is able to go and spend time huddling with their partner and we give them 90 seconds to huddle. When they do this, they will work extremely hard to get access to their partner for that 90 seconds. Now, one of the things that's really cool about this is now we have a way to quantify the behavior, but we can also look at and manipulate the brain at the same time, to ask what are the specific cells within the brain there encoding this desire to be with another individual. In this next video here, what you can see is spiderwebs going across your field of view. These are veins, vasculature within the brain, and then you see occasional flashes of light. These flashes of light are individual cells that had been modified in a way where we can actually see they glow when the cells are active. Using this, we can ask which of these cells are active when an animal is pressing a lever, exerting effort to be with their partner. One of the things we've learned in my lab is that there's a specific set of cells within the brain that predicts when an animal has made the decision to go be with their partner. This is a different set of cells than those that predict when an animal will go and spend time with another individual, another animal that they don't know. One of the questions is what happens when these cells are firing, telling the animal they should go find their partner and yet their partner is not there. In order to study this, we can actually manipulate the scenario so that the animals are given access to a lever. But now when the door opens, their partner is not there and we can look at the neurobiologicamp response to this frustration, this desire that goes unrecorded. Just to finish up, I want to just talk a little bit about the so-what of this? Why should you care? Out of large level animal research is really important because it provides us with biological insights that we don't have access to by studying humans alone. Many of these insights have led to therapies, cures for diseases, and vaccines that have been incredibly important to the advancement of humanity, alleviating suffering, et cetera. But in particular, the reason why I think it's important to study this particular phenomenon, trying to understand the frustration that occurs when we can't engage in our desire to be with a particular individual has less to do with the temporary nature of Covid-19 and the impacts it's having on our lives and more to do with understanding what happens when we experience that frustration and it can never be recorded. In particular, my lab is interested in understanding how this paradigm may be relevant for understanding the pain that manifests when we're grieving an individual that we've lost and ultimately using this information in order to develop ways that we can help individuals who are suffering from the loss of a loved one. Thank you for your time today. I appreciate the opportunity to get this lecture and I hope I get to meet many of you virtually in the future.
