What are the neurons?
The neurons are specialised cells of the nervous system and have the ability to transmit electrical pulses. There are two types — sensory and motor. “All are formed by multiple short arms, called dendrites, which are responsible for receiving signals,” explains Leticia. “The axon is a single long arm responsible for transmitting the signal to other nuclei. The end of the axon connects with one or several dendrites from other neurons in a structure called a synapse. Here, the axon releases chemical molecules, activating the neurons in contact with it.” Both the brain and the spinal cord have two well-differentiated areas, known as the grey matter and the white matter. “Most of the neurons’ bodies are in the grey matter, and the white matter is made up mostly of axons, which are also the main structures in the nerves,” continues Leticia. “In the brain, neurons are located in specific areas depending on their function — memory or taste, for instance.” In the spinal cord, the neurons are also grouped by function in the grey matter, while in the white matter, specific pathways have a specific location. “The grey matter in the brain is mostly on the outside or cortex, while in the spinal cord it’s on the inside, surrounded by the white matter,” says Leticia. “On top of this, the neurons are not alone. An army of helpers surround them to feed, hold and protect them. These are called the neuroglia.”