The Nikon MicroscopyU confocal microscopy image gallery was created with a PCM-2000 confocal scanning system interfaced to a Nikon Eclipse E600 upright microscope. Images were recorded in successive z-axis serial sections with C-Imaging Systems software with excitation illumination provided by an argon-ion and/or a helium-neon laser.

	Interactive Java Tutorial
ATTENTION Our servers have detected that your web browser does not have the Java Virtual Machine installed or it is not functioning properly. Please install this software in order to view our interactive Java tutorials. Visitors using the Netscape and Microsoft Internet Explorer browsers can download the appropriate software from the websites where the browsers are distributed. Please do not contact us for information about specific URLs where this software can be obtained.

Nerve cells are one of the fundamental building blocks that separate organic matter (living organism) from inorganic matter (non-living material such as rocks). Individual nerve cells form links that join together to produce a complex and integrated communications network that runs throughout the entire body. These interconnected cells allow the living organism to communicate or interact with its external environment by transmitting information though a coordinated series of electrical and chemical signals.

Nerves can convey information received by the eyes, ears, tongue, nose, and skin to the brain for processing. For example, the skin may transmit the sensation of coldness to the brain allowing an organism to seek protective shelter. Without requiring conscious effort, some nerves automatically conduct impulses to internal structures and organs and help vital functions to proceed smoothly such as breathing and digestion. Nerve cells also transmit signals from the brain to other parts of the body so that an organism can interact with its environment or with other organisms. For example the brain can signal muscles to coordinate muscle movements that produce speech.

A typical nerve consists three basic parts. The body or soma is bounded by a thin and very fine membrane that is comprised chiefly of lipids. The interior is filled with liquid and contains a nucleus, organelles such as mitochondria, and other specialized protein structures. Extending from the body is an elongated appendage that conducts messages away from the cell body termed an axon. The soma also projects dendrites, which are short branching terminals that receive information from other nerves.