A stroke (also known as a cerebrovascular accident) is a sudden loss of brain function that occurs when the supply of blood to the organ is interrupted. Strokes most commonly occur due to blood vessel blockage, but may also be instigated by intracranial hemorrhaging. Signs that an individual is experiencing a stroke are often highly recognizable, commonly including the sudden onset of numbness on one side of the body, aphasia, confusion, dizziness, loss of balance, and vision impairment in one eye. A stroke is a medical emergency and requires timely treatment to minimize long-term effects. The particular treatment employed depends on the underlying cause of the stroke, with administration of an anticoagulant being common among patients suffering from occlusion-related events.

This widefield fluorescence image of a rat brain tissue section was produced by probing the specimen with Alexa Fluor 488, Alexa Fluor 568, and Hoechst 33342. The two Alexa Fluor dyes were conjugated to secondary antibodies directed against primary mouse anti-NF-P antibodies and rabbit anti-GFAP antibodies in order to label phosphorylated neurofilaments expressed in neurons (Alexa Fluor 488) and glial fibrillary acidic protein in astrocytes and certain other astroglia (Alexa Fluor 568). The nuclear counterstain Hoechst 33342 was employed to visualize cell nuclei. Images were recorded in grayscale with a 12-bit digital camera coupled to a Nikon Eclipse 80i microscope equipped with bandpass emission fluorescence filter optical blocks. During the processing stage, individual image channels were pseudocolored with RGB values corresponding to each of the fluorophore emission spectral profiles.