The Emotions of Mice & Men

What makes a human being? This question, which has been asked since the beginning of history, takes on a different interpretation when applied to translational research. Scientists use animals, from apes to zebrafish, as models for the human body. This practice, which extends back to the ancient Greeks, changes the question from “What makes a human being?” to “What are the core necessities for being human-like?” Up until recently, the criteria for being sufficiently human-like has been solely physiological. What type of cells, tissues, and organs an animal had was enough to determine its ability to serve as a human model. As a result, elements such as socialization, happiness, and cognitive stimulation often went overlooked. For many scientists, the cost to outfit a mouse cage with exercise equipment, mazes, and ample living space outweighed the undervalued benefit. By the 1960’s, cages had become essentially “furry test tubes” that provided the bare minimum to keep a mouse alive.

This standard continued until recently, when a group of scientists, including Stanford’s Joseph Garner, have called for a reevaluation. Citing the fact that only one in nine successful drugs from animal tests work in human clinical trials, Garner argues that enrichment of the animals’ lives holds the key for better human models. As the professor of comparative medicine explained in an interview with Science magazine “If we want animals to tell us [what’s] going to happen in people, we need to treat them more like people”. Although some scientists have called the initiative cost prohibitive with the current funding climate and not easily replicable, a few studies have already shown the benefits of providing a more livable environment. A 2004 paper studied different genetic and environmental factors in the development of Huntington’s disease. They found that mice provided with “environmental enrichment” were much slower than the control mice to develop symptoms of Huntington’s disease, a disease that had previously been considered completely genetic. Another study exposed mice to a “Disneyland for Mice,” a one square meter area which consisted of mazes, running wheels, and multicolored igloos. This study found that stimulated mice developed tumors that were 80% smaller than the control mice. Other similar studies have also found a possible link between the enriched environments and both the similarity to humans and the overall well-being of the mice.

With the growing evidence of the need for lab animals to have more of a social and cognitive life in order to better model humans, a new question emerges. What does this evidence say about the nature of human beings? Scientists and medical practitioners have long agreed on the positive effects of socialization and intellectual stimulation on mental health. Do these effects also extend to physical health? Can these elements of our environment be just as integral to being “human” as having a functional respiratory or endocrine system? Widespread studies from many different disciplines have found a common link between enriched lives, both socially and mentally, and overall health. From cardiovascular health to dental health, social life and stimulation have been found to have far-reaching effects (Peterson et al.; Fontanini et al.). There have even been scientific papers showing a direct correlation between social isolation and increased mortality. The impact of living an enriched life seems to reach all aspects of the human experience, both in the mental realm and the physical.

As more studies emerge on the physiological benefits of these intangible parts of our lives, the upshot can seem somewhat ambiguous. For college students, there is a pressure to take advantage of every possible opportunity. Similar to how the mazes and running wheels of the mice, club activities and volunteering may act as a means for “enrichment” (and a way to pad a resume). However, while the parallel between the mouse cage and the college campus might seem attractive, an important element is missing. Stress. Through the pursuit of enriching activities, a student often also takes on stress due to those same activities. One would not think that a mouse stays up at night, worrying if the number of hours it has spent in the maze is enough. In fact, stress may undo the very effects the activities may have promoted. The effects of constant stress on college student life mirrors the effects of social isolation and a lack of mental stimulation seen in the elderly (Sandi et al.). Achieving a balance helps reduce stress and its negative implications.