The way we find our way in our environment may be even more complex than previously believed. According to a new study, there seems to be a series of neurons that become active whenever rats walk along a particular path — the same may be true for humans.
How Rats Find Their Way
When navigating a city, most of us still manage to find our destination even with a few hiccups like roadblocks. We create a mental plan of the city, so even if we don't have a map around, we can still make pretty accurate assumptions on whether a particular street takes us closer to where we want to go, especially when familiar with the cardinal directions.
The same seems to be true for mice when allowed to roam labyrinths; however, according to a new study at the University of California San Diego, the process behind the ability to find one's way may be even more complex than expected. Several mice were placed in some labyrinths that were designed to be similar to city plans. As they made their way, their brain activity was recorded.
What researchers saw was that certain neurons would fire whenever the rodents walked along a particular axis, such as north-south. When the mice chose another axis, other neurons became active. The neurons were not active, however, in open fields, only on paths.
The Mechanism Behind Orientation
Researchers were surprised by these results, as before this experiment they had only been familiar with other types of neurons, such as those called head direction cells. These particular neurons become active only when the head of the animal is pointed towards a particular direction, including in situations when the particular subject is in an open field.
The neurons identified by researchers in the new study, however, are completely different. They do not become active in open fields, but only when the animal follows a path. These particular cells represent up to 10 percent of an area known as subiculum, which is part of the hippocampus, known for its role in orientation.
"We're describing an entirely new and unexpected form of neural activity. The cells fire when the animal travels in either direction along a single axis," noted senior author Douglas Nitz.
In light of the new discoveries, researchers are now looking into finding out even more about these neurons. For example, they want to know how much experience a rodent needs in order for them to start firing correctly. Also, they want to see how much of this research is also true in the case of people.
