The cerebral hemispheres of the human brain, which feature several prominent sulci and gyri, are considered to be divided into several broad regions termed lobes. Four of these lobes, including the parietal, occipital, temporal, and frontal lobes, can be seen along the surface of the brain, while a fifth lobe, known as the insular lobe, is situated in a fissure beneath the others. The lobes do not function independently of one another, but rather are complexly interconnected. Certain subdivisions of the lobes do, however, play particular central roles in certain neural tasks. For example, the parietal lobe’s somatosensory cortex is specialized for receiving input from temperature and pain receptors, whereas the auditory association cortex located in the temporal lobe serves chiefly as a site where auditory signals are processed and integrated.

A sagittal section of rat brain was immunofluorescently labeled for phosphorylated neurofilaments with mouse anti-NF-P antibodies followed by goat anti-mouse secondary antibodies conjugated to Alexa Fluor 488. Neurofilaments are specialized intermediate filaments solely found in neurons, especially in their axons. In addition, glial fibrillary acidic protein, which is expressed in various astroglia and neural stem cells, was targeted with rabbit anti-GFAP antibodies visualized with goat anti-rabbit secondary antibodies conjugated to Alexa Fluor 568. Cell nuclei were labeled with the popular nuclear counterstain Hoechst 33342. 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.