They live in the deepest and darkest places on earth, crawling through filth and sewers, praying on the decomposing flesh. They spread disease and chaos globally, and are single handedly responsible for the death of 4 million people during the bubonic plague of 1348. They cause you to squirm, squeal and look the other way and I hold them personally responsible for causing my mom to scream bloody murder on the streets of New York City. Of course I am talking about rats.
While rats are made out to be cold blooded killers, for the most part they don’t live up to their reputation. Si-Fi channel has us sitting here believing that all rats are six feet long and eat small children for breakfast. Even though I have some cousins I would like to feed to six foot long rats, they are almost as fictitious as the Blob.
Rats may be my mother’s mortal enemy (not just rats, any rodent, bird, snake, small dirty child), rats can be a psychologist best friend. In my Learning Psychology lab, my lab partner and I work with a rat and are beginning to train her (you can read my rat blog post here). But what makes these squirmy little hairballs a psychologist best friend? What makes a rat’s brain similar to humans? And why is it that so many rats are used in studies and then generalized to humans?
To start I would like to tell you about something I saw on the news the other day. First of all we all know how addicting Oreos are, you eat one, you eat two, before you know it you are online signing up for a gym membership because you ate the whole box. An article I found this week says that Oreos are as addictive as cocaine. To test this they put rats in a maze, one side got Oreos, and the other got less tasty rice cakes. When the rats were set free to explore scientist recorded the amount of time the rat spent on each side of the maze. This time was compared to a study where the rats were given an injection of cocaine or an injection of saline. The researchers found that the Oreos excited the brain’s pleasure center in the same way the cocaine did (Wilson, 2013).
Now while I am sitting here contemplating my apparent drug addiction, I am also contemplating why researchers would use rats over lions or tigers or bears OH MY! There has to some explanation to why rats are used over every other animal.
One reason why rats are used in experiments is because they are mammals, as are humans. Rats systems should react in the same way as humans, if it is safe for a rat, it should be safe for humans. Another reason that rats are good test subjects is for longitudinal studies. Rats can have litters within 20 days of being born, and generally have large litters. This allows scientists to do study’s and look at how a drug, chemical or reaction could affect people over multi generations (“Why are rats,” 2013).
But how does a rat brain compare to a humans brain? How can something so small and fluffy bring us so much knowledge?!?
Typically scientists have been able to link rat nervous systems to human nervous systems due to how they develop. Rat brains and human brains match at seven stages of development allowing the development of rat brains to be compared to humans (“Human-rat comparissons,” 2013). An interactive map of this can be seen (and played) here. This allows you to see that rats have the same components of the brain that humans have just in different areas (Martin).
These masters of the sewers, these dark shadows in the night, these blood sucking vermin, are not really all that bad. Being mammals and having similar brain structures allow us to perform test on these fluff balls and get results as if they were humans. So rats are not all bad, even if they are addicted to Oreos, or cocaine.
My high school psychology teacher made us memorize this song at one point.
Human-rat comparissons. (2013). Retrieved from http://neurondevelopment.org/human-rat-comparisons/
Martin, V. (n.d.). Comparison between the human and rat brain. Retrieved from http://www.wesapiens.org/file/3401005/Comparison between the human and rat brain
Why are rats used in animal testing. (2013). Retrieved from http://www.wisegeek.org/why-are-rats-used-in-animal-testing.htm
Wilson, J. (2013, October 16). Study: Oreos as addictive as cocaine. WFMZ 69 News. Retrieved from http://www.wfmz.com/study-oreos-as-addictive-as-cocaine/-/121798/22468704/-/cig51p/-/index.html