Author Archives: Alina Xiao

BSURF 2018

In my BSURF application, I wrote that I hoped to use this summer to explore a new field of biology and to connect with animals that I had not worked with before. Now at the end of the program, I feel so grateful looking back and seeing that those two things are exactly what the experience has enabled me to do. I found so much satisfaction learning neurobiology, linking animal behaviors to the underlying neural mechanisms. I found so much joy working with mice (except when SuperFiesty bit me, jumped away from my hand and almost gave me a heart attack). During the first week, I felt nervous, unsure, overwhelmed. I remember looking at the schedule for eight weeks and thinking to myself what a long journey it would be. Retrospectively, it was indeed quite a journey. But I can’t say enough how happy I felt with every little step I made along this way, whether that is a deeper understanding of the experiment, progress with the habituation, increasing familiarity with the techniques or simply nice conversations with the people in my lab and with the amazing friends I got to make. Thank you to Dr. Grunwald and Jason for giving me this chance. It has been a valuable learning experience. Like what Dr. David said, I just started to feel so comfortable operating on my BSURF schedule and here comes the graduation. But that’s okay, because every time I walk into the lab again, I’ll remember how all this began.

Yesterday, I told my mentor that when I first looked at the mouse brain on the confocal, it felt like I was looking into a galaxy. In a sense, that’s true for the summer, because I am starting to see a whole new world of ideas and possibilities.

It is with great excitement and gratefulness that we cheer to a future with more science, more friendships, and of course, more mice!

Every Animal Has a Different Reality

One of the many things that I look forward to each week is to hear the faculty talks. While no one can predict what would happen in the future (to quote what Dr. Telen quoted from John Lennon, “Life is what happens to you when you are busy making other plans”), I certainly learned a lot as the speakers shared about the journey they have traveled. Some stories such as that of Dr. Telen, Dr. Kontos and Dean Klotman led me to appreciate a field of biology and the people in that field. Some like that of Dr. Lefkowitz imbued me with so much joy and energy. I was grateful to hear Dr. West saying that never to worry where you will be too much. Nevertheless, through the faculty talk series this summer, I certainly found more strength and excitement as I look forward now.

One talk that particularly fascinated me was Dr. Nowicki’s. Dr. Nowicki’s lab studies categorical perception, using swamp sparrow as one of their models. Among the many interesting studies was the investigation on how female birds see colors. To see if there is a boundary to color perception in birds, the lab trained the female birds to learn that there were only seeds under bicolor pads. By adjusting how close the two colors are on the bicolor pads, the lab was able to find that birds see colors categorically rather than seeing them on a continuum. Nowicki lab cooperates with Mooney lab, which is the lab I’m currently in, to further figure out the neural circuitry underlying bird’s perceptions.

As someone who is very interested in animal behavior and has grown to love neurobiology (thanks to BSURF!!), Dr. Nowicki’s words really stuck with me: “every animal has a different reality”. What we perceive and project onto other animals isn’t necessarily the case for those animals. A couple of weeks ago, I had a conversation with my mentors on categorizing mice vocalizations. My mentor shared that many people analyzed the differences between mice vocalizations in different contexts. She said yes, they have found some differences carrying certain statistical significance, but how much do these differences weigh to mice? Do mice care about the subtle variations when they communicate to each other? Similarly, after observing a juvenile male vocalizing to an adult female but exhibiting no mounting behavior, I was confused if the vocalization should be counted as courtship-directed. Based on my human thinking, a baby boy speaking to a female adult is for sure not courtship. Yet, how accurate is that projection to mice? Something Dr. Nowicki said during his presentation that I will keep in mind forever studying animal behavior,

“we would be better at entangling the world if we jump out of our worldview”.

The faculty talk series with BSURF ended this past Thursday. But with this end, I’m more sure that it is only a start. Dr. Grunwald said that science is about communication. So is life. Thank you to BSURF and to all the faculty members who talked to us this summer for sharing their insights and for inspiring me to seek and appreciate more opportunities to learn from others.

Are the subpopulations of PAG neurons responsible for mice vocalization context specific?

Mice are such wonderful creatures to work with. Those that I habituate every day   have become so nice to me. But there are also those who vocalize enough to make you think yes it’s gonna work and then stop vocalizing right away to remind you the unpredictability in life. Once again, mice have taught me that you cannot force behaviors to happen naturally. Things take time in science, and that is okay! I haven’t got much data yet, but it has been great learning and practicing various techniques, and of course, working with micey of all kinds of mouse-alities.

We have adjusted the project a little bit. Below is an updated abstract:

The midbrain periaqueductal gray (PAG), a highly conserved structure, is crucial for vocalization. Lesions of PAG leads to mutism and PAG stimulation elicits vocalizations across species. Mice produce ultrasonic vocalizations (USVs) in various social contexts. Previously, we used a viral genetic tagging method CANE (Capturing Activated Neuronal Ensembles) to identify a subpopulation of PAG neurons important for female-directed courtship USVs produced by male mice. However, it is unknown whether the subpopulations of PAG neurons responsible for USVs are context specific. Here we tested the hypothesis that the same PAG-USV neurons are active when a mouse produces USVs in different social contexts. We first used immunohistochemistry to stain for the immediate early gene c-fos to examine whether PAG neurons are active when a male mouse produces USVs directed to a juvenile male social partner. We then used CANE to tag PAG neurons activated when a male mouse produced female-directed USVs, and c-fos staining to identify active neurons when the same male mouse produced either female-directed or juvenile male-directed USVs. Using confocal microscopy, we examined the overlap between neurons active during the same or different social contexts. Findings from this study can better our understanding of mammalian vocal control at neuronal level.


A Day in the Lab

I normally start my day at the lab habituating mice to a head-fixation device connected to a treadmill. Mice that are considered habituated will groom and run (and sometimes vocalize a little bit spontaneously) instead of displaying freezing behavior. Before placing them back to their home cages, I usually give the mice some sweet treats for having put up with the treadmill training that day. The goal of this habituation is to get the head-fixed mice to vocalize. Since male mice vocalize most reliably during courtship, I run behavior sessions occasionally during or after treadmill to give the males opportunities to spend time with females.

Depending on the exact content of mice training, I might do histology during or after the habituation sessions. Sometimes, the afternoon is spent learning or performing surgeries (which I’m still very slow at…).

While everyone in the lab has a busy schedule and tries the best to be the most productive every day, one lesson I learned so far is that you can never force behaviors to happen naturally. If the mice refuse to vocalize…mind-blowingly, they just don’t vocalize. If the mice dislike the treadmill…well, I haven’t found the magic wand yet to make them relaxed right away. Working in the lab has been an incredible learning experience beyond just the technical aspect. I’m learning to be patient and flexible, to troubleshoot, and to look positively at the reality that things don’t always work! 🙂

Big Is Small, and Small Is Big

Thank you to everyone for sharing their projects this week! It felt like looking through a kaleidoscope: so many different colors, angles, combinations in biology and in people’s attempts to understand life. One thing I learned from all of your talks is to remember to zoom in and out on this kaleidoscope.

By zooming in, big questions come down to acute focuses. Hsp70 is one of the many things that Bio201 hammered into my head this past spring. Nevertheless, I was still fascinated when Tamanna shared in her talk that the Hsp70 family can facilitate parasite survival by mitigating the effects of temperature change as the parasite enters from cold-blooded mosquito into the warm-blooded human host. Many of the malaria studies that I have read before relate to genetic modification in mosquitoes or massacre of mosquitoes, and Tamanna’s chalk talk directs me to look at malaria from a new perspective. Her zooming in from the big question that Plasmodium falciparum results in falciparum malaria, to the moment this parasite getting transmitted from mosquito to humans through a bite, to finally the C-terminal LID domain of PfHsp70-1 binding with PI3P turned this giant ball of problem into a sharp focus. With her clear delivery, it really became clear to me why her lab is doing what it’s doing (wow that’s some cool stuff) and how a big mystery can be teased apart bit by bit. By zooming back out and looking at the broader applications, one can also see clearly that the small dots on the ITC curves can link together something of great significance.

This applies to every single chalk talk that I had the great pleasure listening to this week. As we become more and more familiar with our lab schedules and more and more at ease carrying out each step after rounds and rounds of repetition, I believe it is important to keep thinking why we’re doing what we’re doing and how everything comes together (eventually). Big can be small, and small can be big.

Be Confident and Always Mindful

Dr. Richard Mooney

With some of his earliest memories being out in the garden, in the woods, and together with the wildlife around his grandparents’ cabin, Dr. Mooney has a lifelong passion for biology.

In college, Dr. Mooney majored in ecology and evolutionary biology. While textbook learning was one of the core components in college education, he found himself going back to the original experiments and asking why certain popular scientific concepts were supported by observations in the first place. Some experiments, such as that of Meselson and Stahl’s determination that DNA-replication was semi-conservative, struck him with their clarity, but he also realized that many higher-ordered, complex, network-oriented systems such as the brain and the ecosystem cannot be explained by one single reductionist approach.  “I don’t understand so many things that I really have to try to figure them out,” Dr. Mooney shared, “I never thought that I would end up in a place I am now, [but] what wasn’t understood compelled me to get to this point.”

From his childhood to his research career, Dr. Mooney has worked with a variety of animals––leafhoppers, butterflies, moths, frogs, snakes, fish, and songbirds. “Whatever I can see close up, I am really engrossed by,” he said. In terms of neuroscience research on learning, nevertheless, he has a special love for songbirds, an “amazingly powerful system” according to him, where juvenile “pupils” learn to sing by copying songs produced by adult songbird “tutors.” By studying such cultural transmission of vocal behavior from tutor to pupil, he sees insights for understanding how humans transmit various behaviors, including language, speech dialects, art, music, and other cultural idiosyncrasies that are fundamental to being human.

Besides science, another layer to Dr. Mooney’s fascination with bird songs and auditory neuroscience comes from his interest in music. As someone who loves biology and music as well, I was amazed to learn that Dr. Mooney went to San Francisco Conservatory of Music for a few years after college graduation. When asked why he made this decision, he shared that he grew up in a family that really enjoyed music and emphasized music education. The amount of change in the musical spectrum in the US during 1964-68 and his love for Laurindo Almeida’s guitar music drove him to take guitar lessons when he was ten. All through high school and college, he struggled to balance science and music. Thus, he promised himself that he would spend at least a year or two after college dedicating himself fully to music, which he did when he graduated from Yale. During the two years he studied with the renowned classical guitarist David Tanenbaum at the conservatory, he spent every spare moment with his guitar and practiced late into the night. Although he eventually decided that he didn’t want to play music in exclusion to everything else (he really missed science), he played a lot and still views guitar as an important piece of his life.

Having been in science ever since, Dr. Mooney is still very excited when he talks about this discipline. He believes that science can “explain things out of our own experience and our own lifetime.” What is more, he has “increasingly come to enjoy the process of watching people become really proficient, helping them become adept and do sophisticated work that goes beyond what [he] could do [him]self.”

“How much fun to have people working [in neuroscience] with me!” he exclaimed.

Thinking back to his own graduate school career, Dr. Mooney laughed as he shared his most embarrassing lab experience. In 1984, the lab he was in just purchased a very expensive computer monitor. Intrigued by a friend’s trick––distorting the beams on an oscilloscope screen with a magnet–– he tried the same trick on the lab’s new monitor. Not appreciating that the design of the monitor was different from an oscilloscope, he left a huge purple mark on the screen. Luckily, the lab technician managed to remove the mark right before the PI walked in. But still, Dr. Mooney drew his lesson from this incident, “Don’t screw with really valuable equipment until you understand how it works!”

Personally, one of my biggest struggles with biology is killing animals to study them. I asked Dr. Mooney, “A lot of people come into this study out of their love and appreciation for life. But sometimes, experiments require biologists to actively end other animals’ lives. Do you find that upsetting or hard to deal with?” Dr. Mooney gave me the most inspiring response I’ve heard so far, “Yes, it is,” he said, “If there is a way to understand the brain without using invasive or ultimately destructive approaches, then that should be used by all means.” He talked about how it is hard and sometimes impossible to understand the neural level of brain structures without teasing it apart, and how studying bird brains, for instance, can teach us a lot about neurodegenerative diseases like Parkinson’s disease. Yet, he emphasized, “Mindfulness in all things is important. Being a good scientist, one has to be mindful what the cost of the experiment entails.” He believes “the human condition is one in which we are driven to understand the world where we live in, and it is something we can do in a way that other animals can’t. There will be a salvation for our own species that will include pursuing that drive to understand the world…We have to come to value more highly how complicated and amazingly beautiful all living things are.”

To all students who aspire to become scientists, Dr. Mooney encouraged, “Find out what you do like. If you really set your eyes on certain goals, you’ll get there.” If he could, he would tell his younger self, “know that you’ll get where you want to get to in time, although you can’t know that for certain when you’re on that path. Have confidence. By having confidence, you will enjoy where you are instead of  being too anxious about where you will be.”

To Vocalize or Not to Vocalize, That Is the Question

Imagine you were an adult male mouse. Do you vocalize when you are in a safe environment with a female? (Duh of course) Do you vocalize when you face a male intruder mouse? (Well, gotta vocalize when appropriate to get the intruder away) What if there is a cat present? (Hmm…better off staying quiet) How would you weigh things out if there is a female and a cat present? (Ughh…Let me check with my brain)

The Mooney Lab is particularly interested in the neurobiology of hearing and communication. This summer, the two projects that I’m involved with focus on the production and perception of vocalization in mice.

Vocalization is crucial to communication and social functioning for many mammalian species. Humans, for instance, rely on complex speech to convey emotions and various information; mice, for another example, produce ultrasonic vocalizations (USVs) for purposes such as courtship and defense (Holy et Guo, 2005; Portfos, 2007). In our society, producing speech appropriately in different social contexts is essential for individuals’ social survival. Similarly, to survive and reproduce, mice vocalize in a context-specific fashion, and thus serve as a model system for studying mammalian vocal control (Chabout et al., 2012; Weiner et al., 2016). In mammals, the neural circuitry for vocalization production is a complex network across the forebrain and brainstem, obligated to integrate cues from social contexts, determine the appropriateness of vocalization and finally signal motor neurons to generate sounds through larynx (Tschida et al., unpublished). However, despite its critical role, understanding of the vocalization network has remained limited at the neuronal level.

Previously, Katie and Valerie (my mentor, wohoo!!) have worked extensively on an area within the midbrain called periaqueductal gray (PAG). PAG is a highly heterogeneous structure, pertaining to nociception, defensive, reproductive and maternal behaviors as well as autonomic regulation (Basbaum et Fields, 1978; Carrive, 1993; Tovote et al., 2016; Tschida et al., unpublished). It has also been shown to be an essential node in the vocalization circuitry, since when PAG is lesioned, individuals exhibit mutism (Esposito et al., 1999; Jurgens, 1994; Jurgens, 2002). Using CANE (capturing activated neuronal ensembles) (Sakurai et al., 2016), a viral genetic tagging method, the lab has been able to characterize distinct subpopulations of PAG neurons that are activated during USVs of male mice to females. Nevertheless, these selective subsets were only characterized in the context of male-female interactions. My first project thus examines two social contexts––courtship with females and defensive behaviors against intruding juvenile males––, and studies whether the same subpopulations of PAG-USV neurons are activated for vocalization in both scenarios.

In the last two weeks, we have performed CANE tagging brain surgery on two mice. I’ve also been practicing doing histology. I’m still very slow carrying out each step during the surgery (special thanks to my mentor for being so patient), but I’ll try my best to getting better at it with every more step I do (and to ALWAYS ALWAYS remember to check how fast the mouse is breathing).

The second project studies mouse’s auditory perception of his own vocalization. Such acoustic feedback has a significant role in vocal production as well, as changes in this feedback could elicit compensatory alterations in what the animal vocalizes (Eliades et Wang, 2002; Houde et Jordan, 2002). A previous study on marmosets showed that cortical neural responses in these primates are suppressed as a result of vocalization, and that this suppression takes place hundreds of milliseconds before the vocalization onset (Eliades et Wang, 2002). To investigate how the auditory neurons in mice respond to the animals’ vocalizations, I was tasked to habituate mice to a head-fixation device in order to obtain clearer electrophysiological recordings.

Working with mice this week, I had quite some philosophical moments, and thought more deeply about biology and my relationship with living things. While more will come in next week’s post on the interview with my PI, I want to thank all in the lab and in BSURF who discussed this big topic of life with me. I’ve learned so much so far, and I can’t wait to find out what comes next!

Mice Love! (weekend sketches)

End of First Week, but Only a Start to a Great Summer!

I have never doubted that I would be a biology major coming into college. However, at Duke, the many branches of this discipline make me both beyond fascinated and somewhat confused (what to focus on?!?!). I am so excited and thankful that I can have this chance through BSURF to explore neurobiology this summer at Mooney Lab. As I embark on this journey, I want to write down some goals and expectations.

While I had experience working in labs before, most of my work consisted of field work in an ecology setting. There were also very important field techniques that I had to learn–such as sweeping honey bees from their frames into a bucket, shaking the bucket strategically and scooping the bees into a jar to do sugar shake varroa test or collecting and staining stigmas. But when I stepped into my lab this Monday, I realized that the set of skills and the scale that we are work on are simply so different from what I used to get trained in. So far my brilliant mentor has already taught me a variety of techniques that require great precision and patience. It is so cool, too, that many of them apply what I learned in BIO201 this spring. This summer, I hope not just to learn as much neurobiology knowledge as possible, but also to learn and to eventually perform various techniques confidently and independently. I understand that it takes a lot of time and energy to train new people. I am very grateful that my mentor has been there for me. I hope I can become helpful and make positive contributions to the lab as well.

Additionally, I want to become more and more comfortable working with mice in the sense that they can feel comfortable when I handle them. I feel privileged working with and learning from these animals, and I want to make it as stressless as it could be for them, too.

Since this is a new field of biology for me, I want to develop my communication skills, especially through asking questions and discussing experimental setups/progress with others. Both inside and outside the lab, I hope to learn what others are working on and how they become interested in what they are doing. Dr. Telen’s journey in science amazed me. Her talk made me determined to take the initiative to learn more inspiring stories from other people.

When I started this week, one of my biggest goals for the summer is to explore a new area of biology and see whether I like it. Five days later, I already know that I’m so so happy I get to study in Mooney Lab. I am so fascinated by what I’ve learned in the lab so far and I can’t wait to continue learning here during the rest of the summer (and hopefully even after this summer)!

Me next to the habituation station!


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