The signals, in the form of electrical impulses, travel down the length of the nerve cell. Repeated activation of networks of neurons strengthens these connections. These connections are miracles of the human body. But to understand their power, you have to multiply this miracle by trillions. A single cell can connect with as many as 15,000 other cells.
Experience shapes the way circuits are made in the brain.
From birth, the brain is rapidly creating these connections. A baby's brain is super-dense, and will stay that way throughout the first decade of life. The circuitry it ends up with is more powerful and efficient. This is where early experience comes into play. When a connection is used repeatedly in the early years, it becomes permanent.