Neurons are highly specialized cells that transmit electrical impulses between different sites of the body. Neurons interact with other nerve cells as well as various other cell types through the processes known as axons and dendrites. Each neuron possesses multiple dendrites that act as receivers of impulses, carrying them toward the cell body, which is the region that contains the nucleus and main organelles. Most neurons only possess a single axon, however, which carries impulses away from the cell body. Synapses are the specialized junctions between two neurons, or a neuron and a muscle cell. Impulses are transmitted across these junctions through the action of neurotransmitters.

The culture of HCN-1A neuronal cells exhibited in the digital image above was labeled with MitoTracker Red CMXRos, Alexa Fluor 488 conjugated to phalloidin, and DAPI, targeting mitochondria, filamentous actin, and nuclear DNA, respectively. Images were recorded in grayscale with a QImaging Retiga Fast-EXi camera system coupled to an Olympus BX-51 microscope equipped with bandpass emission fluorescence filter optical blocks provided by Omega Optical. During the processing stage, individual image channels were pseudocolored with RGB values corresponding to each of the fluorophore emission spectral profiles.