Rods and Cones of the eye - These cells are extraordinarily sensitive to the radiation wavelengths of visible light. Able to detect a single candle burning at a distance of 30 miles, these cells have virtually no axon and can transmit their information only a very short distance. Bipolar cell - These cells are found only in the retina of the eye and are responsible for taking the information from the receptors and reconstructing it so that it can be sent to the brain. They have dendrites which can extend all the way from the spinal cord, where the cell body is located, to the tip of your finger. The axons then carry the information, as part of the spinal cord, all the way to the brainstem.
Information passes from cell to cell by way of a structure called the synapse .
Much of the extraordinary complexity of information flow within the nervous system can be attributed to chemical transduction at the synapse. These cells perform critical functions throughout the nervous system. These feet brace the astrocyte against other astrocytes and structures. The astrocytes maintain very precise spacing among neurons and blood vessels. It is thought that astrocytes are responsible for producing the phenomenon known as the blood-brain barrier.