The brain is composed of neurons and neuroglia, the two basic cell types of the nervous system. Originally neuroglia were believed to function only as a structural support system for neurons, but they have since proven to have properties similar to the electrically excitable neurons and most likely serve other purposes within the brain.

An individual neuron is composed of a cell body surrounded by branched structures known as dendrites and a single fibrous axon. Typically, the dendrites act as receptors, receiving the impulses of adjacent neurons and conveying them to the cell body. Axons, on the other hand, primarily transport the nerve impulses from the cell body to the dendrites of neighboring neurons. Neuroglia, sometimes referred to as glial cells, surround the brain’s neurons and are present in significantly greater numbers than their counterparts.

Recent studies in neuroscience suggest that brain disorders and injuries may have more potential for successful treatment in the future. For many years, scientists believed that the primate brain was unable to grow new cells or repair itself, but the view has slowly dissipated. Evidence has increasingly supported the idea that neurons are added continually in certain parts of the brain, including the olfactory system and the hippocampus, which is thought to be important in the construction of memories. The new scientific findings imply that the brain’s innate repair mechanisms may eventually be harnessed to treat conditions such as Alzheimer’s disease.