From Mickey to Morris – A Reflection on Mice, Metaphor and Medical Science

As a postdoctoral fellow who spends her days conducting basic science research, I have noticed mice unexpectedly become a familiarity within my daily life. However, the first mouse I ever encountered wore red shorts with white buttons and white gloves.

Mickey Mouse, printed on matching shirts that my grandmother gave to my sister and me, was my introduction to mice — cartoon mice, that is. He occupied every Sunday morning of my childhood as his animation aired on TV. Then there was Jerry, the clever rodent perpetually outwitting Tom the cat every Saturday afternoon on television. During the weekdays, there was Ddol-gi, the leader of the Little Rascals Guard. These fictional mice populated my childhood, but actual mice — living, breathing rodents — remained entirely abstract.

I never imagined encountering a real mouse until medical school, when they appeared briefly during laboratory classes. After the semester ended, mice returned to being black letters and dots in scientific articles — theoretical entities rather than living creatures. A mouse was rarely a subject worthy of contemplation.

Then I entered the world of biomedical research, and I started meeting them — dozens of them — every day.

Initially, the rustling sounds filling the space sent shivers down my spine. However, as time passed, I gradually grew accustomed to handling and experimenting with them. As I have been conducting repeated behavioral experiments designed to assess their cognitive function, I started contemplating the mice themselves.  The thought that had begun with “When did I first meet a mouse?” evolved into recalling my childhood, filled with characters modeled after them. It was somewhat shocking. Thoughts extended from moment to moment during behavioral experiments, as I encountered with my own eyes the real-life forms of creatures that had previously only appeared abstractly in proverbs and idioms.

It started with the Morris water maze, a standard procedure in which mice swim in a circular pool to find a hidden platform after five days of training, designed to assess their spatial learning and memory[1]. I found myself recalling the Korean idiom, “a water-soaked mouse,” used to describe someone who looks pathetic or bedraggled. I never expected to witness the literal inspiration for this expression. I saw numerous mice that looked smaller when their fur flattened after I pulled them from the water. Afterward, what struck me was that they looked least presentable not while swimming nor just being pulled out of water — rather, they looked slick and glistening like hair styled with pomade — but when their fur began drying with a paper towel and stood out in all directions.

This observation made me think about suffering: Perhaps we appear most disheveled not during our immediate and extreme crises but in the awkward recovery period that follows, when we’re trying to find our way back to normalcy. This recognition can encourage anyone who feels they are in their worst moment. The moment they feel most inadequate might actually be when they have already overcome a truly difficult and challenging hurdle and are now shaking off the water that heavily weighed them down, beginning to dry, and entering a period of rebound.

Once the floodgates opened, more proverbs involving mice started coming to mind. How prevalent they were, interwoven so closely into everyday life! Idioms were suddenly animated by scientific observation.

In the world of biomedical research, in vivo studies with small animals are indispensable. Those who enter this world might feel like “a mouse trapped in a pot,” which describes someone with no escape route from an inevitable fate. Perhaps the researcher is like an elephant or a cat. Like the proverb, “an elephant fears a mouse the most,” which metaphorically describes fearing a humble, insignificant being, they might fear these small animals. The feelings of sorrow for their sacrifice or the burden of putting them through tests might be akin to “a cat thinking of a mouse” — which means pretending to care for others in an unreasonable way.

However, I choose to label this journey as an expansion and growth of thought: taking an entity that was once merely a cartoon character not present in reality, then a metaphor found carelessly in everyday expressions and proverbs, then black letters and dots on paper and points on a graph, and finally bringing it into existence as a real, living being and a subject of profound reflection. Thinking about how much gratitude there is in every step we take on the way to understanding the human body, comprehending disease and moving toward treatment, I believe the best course of action is to concentrate on the work at hand, ensuring their sacrifice and our gratitude are not in vain.

[1] Morris, R. (1984). "Developments of a water-maze procedure for studying spatial learning in the rat." Journal of Neuroscience Methods, 11(1), 47-60.