They are called Nervous Tissues.

Nervous tissue is a kind of tissue with a high concentration of cells. Two kinds of cells make up the cellular compartment: neurons and supporting cells, often known as glial cells. The peripheral nervous system (which includes the peripheral nerves and nerve ganglia) and the central nervous system (which includes the brain and spinal cord) both have their own subtypes.

Glycosaminoglycans and proteoglycans make up the extracellular matrix, which aids in cell support and adhesion. In H&E sections, no fibrils (e.g. collagen) are evident in the extracellular matrix, but it has a uniform appearance.

Neurons are big cells with a body and two types of processes: many dendrites and a single axon.