The Nissl stain. Presented here is a Nissl-stained coronal section through the rat hippocampus, at ...

The Nissl stain. Presented here is a Nissl-stained coronal section through the rat hippocampus, at two levels of magnification to illustrate two uses of Nissl stains. Under low magnification (top panel), Nissl stains provide a gross indication of brain structure by selectively staining groups of neural cell bodies—in this case, the layers of the hippocampus. Under higher magnification (bottom panel), one can distinguish individual neural cell bodies and thus count the number of neurons in various areas. (Courtesy of Carl Ernst and Brian Christie, Department of Psychology, University of British Columbia.)