Multipolar neuron

The cell body of a neuron houses the nucleus and is the major synthetic region of the neuron.  The nucleus of most nerve cells is large and very euchromatic with a prominent nucleolus.  These features reflect the intense protein synthetic activity of these cells.  The inset shows a low magnification of the spinal cord and indicates the position of this neuron.

The cell body of a neuron houses the nucleus and is the major synthetic region of the neuron.  The nucleus of most nerve cells is large and very euchromatic with a prominent nucleolus.  These features reflect the intense protein synthetic activity of these cells.  The inset shows a low magnification of the spinal cord and indicates the position of this neuron.

The cell body of a neuron houses the nucleus and is the major synthetic region of the neuron.  The nucleus of most nerve cells is large and very euchromatic with a prominent nucleolus.  These features reflect the intense protein synthetic activity of these cells.  The inset shows a low magnification of the spinal cord and indicates the position of this neuron.

The axon hillock is a specialized region of the cell body that lack basophilia and is the site of origin for the axon.

Nissl substance is an accumulation of RER and polysomes in neuronal cell bodies and dendrites.  The presence of Nissl is one characteristic of dendrites which discriminates them from axons.

Multiple dendrites can be seen, containing Nissl bodies, which are large accumulations of rough endoplasmic reticulum and polyribosomes. The presence of these basophilic Nissl bodies distinguishes dendrites from axons. Dendrites branch at acute angles.

The axon is a singular process that conducts the action potential. It lacks Nissl and originates from the cell body at the axon hillock. The first portion of the axon is the initial segment which is rich in sodium channels and is the initiation site for the action potential.

Myelin is an insulating wrapping of axons, produced by oligodendrocytes in the central nervous system.  This section is counterstained with Luxol fast blue which stains the myelin sheath turquoise-blue.

Glial cells are the supporting cells in the CNS and are comprised by astrocytes and oligodendrocytes.  In most preparations, only the nuclei of these cells are visible.  Special stains, such as a silver stain, are required to reveal the cytoplasm and cell processes.  Supporting cells dramatically outnumber neurons in the CNS.

An artifactual space caused during tissue processing surrounds the neuron.  Artifactual spaces often occur when tissue components shrink or swell at different rates.