Faculty Spotlight Interview with Dr. Maria Tosches

October 24, 2023

What was your undergraduate experience like and how has that informed the way you teach?

My undergraduate experience was highly unusual. I was born and raised in Southern Italy, in a tiny village of farmers, and at the end of high school I was fascinated by the idea of becoming a scientist but I had no clue about how to get there—I had only seen scientists on TV shows. Thankfully, a classmate told me about a small undergraduate institution in Pisa, called Scuola Normale Superiore, where top students selected after a national competition were trained to become scientists. I studied the whole summer to pass the admission exam, and I was one of the three biology students selected that year. Becoming a “Normalista” – this is what students at the Normale are called – literally changed my life. I was immersed in an environment of like-minded students and I had a college experience similar to the American college experience (but very uncommon in Italy). I had to enroll at the University of Pisa and take large lecture classes, but in parallel I was also taking classes at the Normale—these classes were small and afforded a lot of time for in-depth discussions and learning. We would often read scientific articles, and once per year we had to present a thorough literature review on a topic of our choice. These classes at the Normale were a critical component of my training as a young scientist.

Now at Columbia I am teaching a small seminar class on Brain Evolution. The opportunity to discuss scientific papers in depth and to get to know students well reminds me of my classes at the Normale. I’m discovering that these types of classes are very rewarding not only as a student, but also as a lecturer.

What was your path to Columbia, and how long have you worked in the Biology Department?

I moved to New York City in September 2019, so I have been at Columbia for four years now. It feels much longer – so much has happened in between! Before Columbia, I lived in Germany for 12 years, first as a graduate student at the European Molecular Biology Laboratory (EMBL) in Heidelberg, then as a postdoc at the Max Planck Institute for Brain Research in Frankfurt. As a postdoc, I studied the evolution of the cerebral cortex, the brain region involved in our higher cognitive abilities, by comparing our cortical cell types to those in animals with simple cerebral cortices, such as turtles and lizards. Starting my lab at Columbia gave me the freedom to pursue the research questions I am most passionate about. We are still working on brain evolution, but now my lab takes a broader multidisciplinary approach, combining developmental, transcriptomic, and behavioral studies, in a new species: the salamander Pleurodeles waltl. Starting this new research (while dealing with the cultural shock of moving across continents) was a big adventure, and I am not sure this would have been possible in many other places. The energy and talent pool of New York City are really special.

What is the most surprising thing you have discovered in your career as a scientist?

As a graduate student, I was studying a special type of brain photoreceptors in the larvae of a marine worm, Platynereis dumerilii. I had found that these cells express melatonin-synthesis enzymes, and that melatonin slows down locomotion at night, suggesting that these brain photoreceptors release melatonin at night to induce a sleep-like state. I was very curious to know how melatonin acted on the motor system. So, I decided to study neuronal activity in these little larvae using genetically-encoded calcium indicators, which were fairly new at the time. I will never forget the first time I saw, in the middle of the night, larval motoneurons flashing under the microscope! Imaging neuronal activity gave me the opportunity to see how the activity of these neurons was modulated by melatonin and circadian state. I am not sure this was the most surprising thing I discovered, but it was for sure one of the most rewarding.

What do you see as the most interesting open question in your field?

In my lab, we are interested in reconstructing the evolution of the vertebrate brain, and our recent focus has been the evolution of neuron types, the brain’s building blocks. Progress in sequencing technologies now allows us to systematically compare neurons across species on the basis of their gene expression profiles (“transcriptomes”). We can find neurons with remarkably conserved gene expression despite millions of years of evolutionary divergence. The big question is whether these molecular similarities have any meaning for understanding the evolution of brain function. Do neurons with similar transcriptomes play similar roles in the brain? Can we use these molecular similarity data to predict cross-species similarities at other levels? Answering these questions requires going beyond comparisons of gene expression profiles and taking a true holistic approach to brain evolution research. 

If you had never been a scientist, what would you be? 


A chef, maybe. I love to experiment in the kitchen and try new things. Being at the kitchen counter gives me the same fulfillment as being at the lab bench, but with the difference that cooking experiments give results much faster (except for the three-day protocol for Panettone!).