Next the researchers looked for changes in the number of nerve cells between the two groups of animals. In comparison to sedentary mice, the brains of mice that exercised had about 2.5 times more new nerve cells. New nerve cells were not distributed evenly throughout the brain, but were concentrated in the dentate gyrus, a section of a larger area of the brain called the hippocampus. The hippocampus plays a central role in many memory formation processes, including spatial learning locating objects in the environment and consciously recalling facts, episodes, and unique events. A large body of research supports the theory that LTP essentially a strengthening of the synaptic connections between two neurons is the primary mechanism involved in the formation and storage of long-term memories by humans and animals.
Neurons communicate with each other by sending signals through synapses.
Examination of the tissue slices showed that the exercising mice displayed twice as much long-term potentiation compared to their sedentary counterparts. And, as was the case with neurogenesis, increased LTP occurred only in the dentate gyrus. He added that these data also confirm that the structural and physiological changes that occurred in the dentate gyrus correlate with a learning behavior associated with this region of the brain. Numerous human studies have shown that exercise increases alertness and helps people to think more clearly. Recently, Gage demonstrated that new nerve cells grow in the adult human dentate gyrus.