With snow white fur, curious twitchy whiskers and little red eyes, lab rats don’t resemble street rats. They are bred, groomed and sold specifically for research. They are often well-cared for clones. They are certainly cleaner than any house dog. The battery of tests run on rats are many. One such test is all about object recognition. The rat will first be exposed to a new environment – a square, black box. Following their familiarization to the environment, the testing can begin. Rats are exposed to objects – some are objects that they’ve seen before, and some are new. Rats are curious creatures, and they tend to explore novel objects more closely than they might explore an old object. After all, they’ve already explored that one. This is often the case in young rats. Older rats, however, might not follow this trend. Why? They don’t remember the first object and thus treat both as though they are novel.
In a recent object recognition study, researchers tested whether an injection of secreted amyloid precursor protein-α (sAPPα) might help older rats to remember the objects. Bilateral intrahippocampal injection into the older rats significantly improved their performance in the object recognition task. Interestingly, this same performance enhancement was not seen in the watermaze task – where rats are tasked with finding a platform in a pool of cold water. Younger rats are better at remembering where the platform is in the pool and, over time, some will swim right to it. Older rats struggle with the task at a higher rate. The watermaze task is associated with spacial memory, which researchers now believe is not as well preserved by sAPPα injections.
What does this mean for you and me? We may not be rats, but our rodent friends are used as test subjects because they have more in common with us human-folk than is immediately obvious. Many of the pathways and brain structures are quite similar to their human counterparts. That these nootropic injections helped aging rats to remember objects, bodes well for their ability to help people as well.