Glia are the supporting cells of the neurons and have many functions not all of which are clearly understood, but include providing support and nutrients to the neurons. Nuclei are connected to other nuclei by tracts of white matter. Neurons are often grouped into a cluster known as a nucleus where they usually have roughly similar connections and functions. The two main neuronal classes in the cerebral cortex are excitatory projection neurons, and inhibitory interneurons around 70-80 per cent are neurons, and 20-30 per cent inhibitory interneurons. Neurons are the excitable cells of the brain that function by communicating with other neurons and interneurons (via synapses), in neural circuits and larger brain networks. The two main types of cells in the brain are neurons, also known as nerve cells, and glial cells also known as neuroglia.
The rest of the brain tissue is structural or connective called the stroma which includes blood vessels.
Brain cells make up the functional tissue of the brain.
