Growing up I had many talents and interests, I wanted to become a lawyer in new york, a united marine or a paleontologist. I always thought, that I didn't have the perfect scientist story. The she-was-always-so-curious-about-science, the she-won-every-science-fair story. But then a year ago, my first grade teacher send me a letter that said, "Dear Dr. Zwaka, this is how it all begun..". It's a picture of me in first grade staring in a small tank with tadpoles and a small booklet next to me with all my investigations written down. Then I realized, I always was fascinated and in love with nature. Rescuing earthworms from my mom's garden to the compost when she was digging a hole, covering my rain jacket in snails on a walk with my parents or learning what a plant needs to grow. I think, this is my scientist story, this is who I am, an open- minded scientist, excited by many topics but still able to dig in, get dirty or sit in front of an experiment for hours and still be amazed.

During my fourth year of studies, I rotated in a neuroscience lab working with bees which turned into my diploma thesis. The aim of my project was to record from single cells in a bee brain as big as a needle head while the bee was smelling an odor. A meticulous procedure that included sitting in front of a bee with a glass capillary as thin as a hair in her brain and moving the capillary up and down for hours day after day hoping to rapture inside of a single brain cell. During the procedure, I could only follow my hearing, waiting for the rewarding pulsing sound of the electrical signal send from one brain cell to another. Once I hit a cell, I would blow an odor on the antennae of the bee and note the change in the cell signals. The biggest reward was the staining though. After the recording, I added a stain to the cell that allowed me to record the anatomy of the cell. Beautiful trees spanning the whole bee brain with small branches covered in small blebs at the end that connect them to the next cell. Fascinated by the anatomy, I wrote a paper about the cells and the amount of connections they make in different brain areas of the bee brain to different cells. My work led to insights into how information about odors are connected to reward information in the bee brain that allows bees to remember flowers they have visited in the past.

Dreams can be very vivid and real. On the other hand, woken up out of deep sleep and asked what we dream about we say things like car, ball or chair. What dreams are still remains an open question in neuroscience. One theory is that during deep sleep our memory is replayed in order to be consolidated and thats what we report when we are woken.

During my PhD at the Freie Universitaet Berlin I investigated whether honeybees also use sleep to consolidate memory. Bees are excellent learners and remember different colors, odors and even patterns. We trained them to associate a heat stimulus with a sugar reward. During the learning, they were also receiving an odor, which we call a learning-context odor. During deep-sleep phases we presented the same context odor again to the bees with the idea that we could reactivate the memory and thus create a stronger memory. The next day, I tested their memory and the bees that received the reminder odor during the night remebered much better than the animals that only received air. Using this trick, I could show that bees reactivate their memory during sleep, just like humans. So, do bees dream? We don't know yet but we do know that they might sleep for the same reason we do, to consolidate what we learn during the day.

We spent about one third of our life sleeping, yet the function and mechanism underlying sleep remain one of the big controversies in modern science. Even though the role of sleep is still unknown, we all know the consequences of too little sleep. A night without sleep makes us feel tired, slow, foggy in the head, and impacts almost every aspect of our daily life. A lesson I had to learn the first year after my son was born. But what happens in the brain when we wake up every hour and do not get enough sleep? Thats the question I asked myself during my postdoc at Harvard University. We cannot look into a sleep deprived human head and simply see what changes and where changes occur. Fortunately, there is an animal that allows us to do exactly that. It’s a small fish called zebrafish that is translucent when it is small. We can make every brain cell communication in their brain visible, electric signals that show up as light under the microscope. A firework of brain activity. Luckily for us, the zebrafish also sleeps! Equipped with this wonderful toolkit, I set out to establish the zebrafish as a model organism for sleep deprivation. Using light, I kept the animals awake during the night and watched for changes in their behavior the next day. I found that just like humans they decrease their movements after a night without sleep. Intrigued about the similarities, I set out to compare simple cognition before and after sleep deprivation. In humans and other animals, we know that a night without sleep leads to slower reaction times and worse decision making. Just like I expected the reaction time to a stimulus became longer when the zebrafish didn't sleep enough. However, to my surprise, the little fish became better in a simple decision-making task. I hypothesized that because the fish takes longer to make a decision, it has more time to integrate the stimulus and thus makes a better decision. This is the first evidence that sleep deprivation leads to changes in behavior and thus to changes in the brain of larval zebrafish. My results set the ground for understanding the changes that happen in the brain after sleep deprivation.