Our Brain’s GPS
Wouldn't it be fantastic if our brain had its own GPS? Share on X I’m picturing myself at my local shopping mall. I’ve shopped here regularly for years. It is always too busy to park in the same spot but I tend to park in the same general area each time.
I like to park close to the grocery store because with three teenagers I’m always out of food so the grocery store is usually my last stop before I head home. How is it I can remember the spot I’ve parked in and differentiate that from the hundreds of other times I’ve parked in the same lot though different parking slot?
I have to admit that as I get older, it gets harder to do.
If I am in a hurry and don’t take note of my surroundings before dashing into the store for the needed items before I rush off to pick up the kids at one of the dozens of activities they might be at, I will have that momentary oh shi……. before I relax myself, take stock of my surroundings, rack my brain, walk aimlessly for a bit and then recognize the football sticker on the back of my van that signals I’ve hit pay dirt!
However, that being said, I usually do take a good look around after I park. I don’t bother noting the cars on either side of me. They’ll probably be gone before I return. I do however, take note of what part of the mall is directly next to my row. For me, that is key and allows me to quickly sift through similar memories to find my van for the hundredth or so time in my lifetime.
But, the question is, how do our brains perform this miraculous feat? How do we differentiate between very similar memories? Share on X Better yet, how do our brains record the information for any memory at all?
It was a mystery. But thanks in large part to three Nobel winning scientists, the mechanism of recording memory is becoming clearer.
The human brain has 100 billion neurons, each neuron connected to 10 thousand other neurons. Sitting on your shoulders is the most complicated object in the known universe. —Michio Kaku
And the Nobel Prize for Medicine 2013 Goes to…..
In 2014, the Nobel Prize in physiology or medicine was awarded to three scientists: John O’Keefe of University College London, and husband and wife, May-Britt Moser and Edvard Moser of the Norwegian University of Science and Technology in Trondheim. Both groups of scientists performed experiments on rats, one of the animal kingdom’s best navigators, and discovered the nerve cells, the brain’s GPS system, that rats use to make sense of their environment in part by keeping track of their place.
O’Keefe’s discovery came first in 1971. He found that certain cells in rat’s hippocampus devoted to memory only became active when the rat was in certain spots. These cells were called ‘place cells’ and are in the CA3 area of the hippocampus. It is these place cells that allow the rat to record a detailed map of its surroundings.
nih, public domain,via openi.nlm.nih.gov
About 30 years later, the Mosers discovered a second piece to the puzzle of location memory. In the entorhinal cortex, located near the hippocampus, they discovered cells that only fired as the rat passed through certain locations. As the rat passed moved, these grid cells fired at regularly spaced intervals in a hexagonal pattern. Other cells collect information about the rat’s head position while others note a location’s boundaries and together with grid cells send this information to the place cells in the hippocampus. This elaborate neural network tells the animal its place in space!
Humans have their Own GPS Neural Network Too!
Now, you might be thinking that rats have this marvelous memory neural network but what about us. Scientists have found these same cells in humans too. Using implanted electrodes, place cells were discovered in humans in 2003, and in 2013, grid cells were discovered. Thank goodness for me and finding my parking spot. This system is extremely fine-tuned in rats and in people. The place cells develop such distinct firing patterns, even very similar memories can be distinguished – like me finding my parking spot in a lot I’ve parked in hundred’s of times but in slightly different spots each time.
The Brain’s GPS and Alzheimer’s Disease
This research presents important implications in human development and memory impairments. The brain’s GPS system is important in developing infants as many memories rely on our sense of our body’s place in space. In Alzheimer’s disease, this neural network is the first affected. One of the earliest symptoms of this disease is the loss of the ability to successfully navigate in familiar places. Knowledge of the mechanisms of memory can only give hope that effective treatments can be developed to slow down the development of diseases like Alzheimer’s or perhaps a cure may be found by stimulating the re-growth of lost navigational cells. Only time and further research will gain further inroads; however, it is a hopeful achievement!
Sources
Sanders, Laura. Neuroscientists garner Nobel for discovering brain’s ‘inner GPS’. October 6, 2014. Science News. December 10, 2014.
Yeager, Ashley. Place cells in brain reveal how memories are kept separate. December 9, 2014. Science News. December 10,2014.
