Always at the Right Place: The Brain with Space and Time
Written by Janelle Nieva
Edited by Hannah Parducho
May 2, 2021
Edited by Hannah Parducho
May 2, 2021
Do you ever wonder how you can easily remember the way from your house to the local grocery store, or simply distinguish where the bathroom is from the bedroom? It might seem like common sense to remember all these locations we encounter in our day-to-day lives, but the neurons in our brain are hard at work and firing rapidly to make sure we get to the right place at the right time.
Two studies done by researchers at UT Southwestern observed the function of two important types of cells that are responsible for how we efficiently get to where we need: time cells and place cells. Time cells have to do with our formation of memories and the ability to order them properly. On the other hand, place cells record the specific locations of where events take place, forming a mental map. These cells can be found in both humans and animals. They are located particularly in the hippocampus, which is the region of the brain associated with processing memories.
In the first study led by Bradley Lega, M.D., memory retrieval was tested to observe the activity of time cells in humans. The volunteers consisted of epilepsy patients from Peter O'Donnell Jr. Brain Institute. The task was to read 12 words on a list for thirty seconds, then do a short math problem. After that, they would try to recall as many words as they could within thirty seconds. The idea is that the person associates each word with a piece of time, which stimulates the time cells to fire. The activity of time cells gave a prediction of how well someone could make these associations and recall the words from the list in order -- a process called temporal clustering.
The second study, led by Brad Pfeiffer, Ph.D, examined place cells in rats. The rats were put either in a square arena or a long straight track, where they were motivated by wells of chocolate milk (yum!) to move around. As the rats went through these areas, the neurons displayed a rapid back-and-forth switching of mini-sequences that recalled the old, and expected the new.
Now we know how our brain works to remember the times and places we go -- so where do we go from here?
Imagine the process of encoding when and where we go like navigating a map: knowing how to decipher this map can allow us to find shortcuts and efficient ways past tough hills. With this research, scientists are working to find new ways to treat memory loss from neurological conditions such as Alzheimer’s disease and traumatic brain injuries. This takes us one step closer to discovering new treatment methods. So next time you forget how you got from point A to point B, remember the rats and their chocolate milk!
References
UT Southwestern Medical Center (2020). “How the brain remembers right place, right time.” Retrieved February 20, 2021, from https://www.sciencedaily.com/releases/2020/12/201208163021.htm
Image Source: “Neurons” by NeuroCyto Lab, INP, Marseille, France in National Institute of Health Gallery licensed under CC BY-NC 2.0.