Atticus Pinzon-Rodriguez

I have been fascinated by animals for as long as I can remember. My favourite subject in school was of course biology, specially anything related with senses. I was intrigued and captivated by the sensory strategies of animals, especially by sensory modalities not present in humans.

As a biology student at the Universidad Nacional de Colombia (National University of Colombia), I realized that the animal physiology was the road to follow to learn more about sensory systems, strategies and adaptations in animals. For the last part of my bachelor studies, I was devoted to cell and molecular biology courses and animal physiology. Following my bachelor’s degree, I started my master’s in physiology at the same university. I focused on the intracellular signalling cascade used by melanopsin, a novel opsin that mediates circadian synchronization and other non-visual responses in vertebrates. The model was the chicken embryo retina, that I used both for immunodetection of proteins involved in the cascade and to obtain dissociated amacrine and horizontal cells expressing melanopsin, to attempt electrophysiological recordings.

After obtaining my master’s degree, I took a break from research but stayed in academia in a more administrative role. I worked with the Academic Vice-Rectory of the same university, coordinating auto-evaluation processes with accreditation purposes, academic internationalization and other related activities. I learned a lot about the internal workings of the University and how higher education evolves over time.

Then I was awarded with a scholarship from Colombia’s government to complete my PhD studies abroad. After searching for a few months, I found the Vision Group at Lund University: the perfect place to continue my research in sensory systems. I was lucky enough to be accepted by Rachel Muheim as my supervisor, to study the light-dependent magnetic compass in birds, using different experimental approaches to answer diverse questions about the proposed mechanism. The model I used was the zebra finch, a nomadic species that is known to have a functional magnetic compass.

During my PhD we studied the behavioural responses of the zebra finch to characterize the functional properties of the magnetic compass. We discovered that the spectral properties of the zebra finch compass are the same as described for migratory birds, which means that the magnetic compass is a general mechanism for all birds, not an exclusive feature of migratory birds. We also analysed the gene expression patterns of Cryptochromes in the zebra finch retina. Cryptochromes have been proposed as the putative magnetoreceptors because of their ability to form radical-pairs upon light excitation. Those radical-pairs can interact with magnetic fields as weak as the Earth’s magnetic field, which makes them ideal candidates to be magnetoreceptors. Cryptochromes, however, have been classically and mainly described as key elements in the circadian machinery of plants and animals. We discovered that some cryptochrome genes, Cry1 and Cry2, follow a circadian pattern in the zebra finch retina, most likely because they are part of said mechanism. On the contrary, another cryptochrome gene Cry4, expresses constantly, with no daily variations. This may indicate that Cry4 is not connected to the circadian machinery, and probably has a different role, like magnetoreception.

The last part of my PhD time was devoted to describing the location and distribution of both Cry1 and Cry4. Cry1 because it was originally proposed as magnetoreceptor (our gene expression evidence says different) and Cry4 because ours and other lines of evidence suggest that its intrinsic properties, as well as its expression pattern makes it an ideal candidate to be the magnetoreceptor. To study this, we resorted to immunohistochemistry, using antibodies to detect the specific retinal cells that express Cry1 or Cry4.

I completed my PhD during the spring of 2018, and I continued working with the Vision Group under the supervision of Rachel Muheim to expand the findings we obtained during my PhD.

During my PhD I not only combined several methods ranging from behavioural tests, molecular biology and immunohistochemistry to answer my research questions, but also honed my skills in graphic design to produce visual aids for teaching and general science communication. I was involved in teaching of Zoology, Human Physiology and Sensory Biology, tasks that I enjoyed and look forward to repeat. During my bachelor studies and now during my PhD studies, I was also involved in the organization of student meetings and biology conferences, at the national (Colombia) and local (Lund) level.

My original scholarship requires me to go back to Colombia and work supporting and improving the local research and higher education system. After being educated in a foreign institution, it is clear for me that collaborations and exchange programs are a basic pillar of research. I hope I can facilitate such activities and work as a bridge between Colombia and Sweden.