Nervous System

Brain - Necrosis

    Appearance of a thalamic infarct at low magnification, identified by pallor within the zone of the black arrows, in an F344/N rat. The dentate gyrus of the hippocampus is identified by a white arrow. This infarct was the result of an arterial embolus (arrowhead), shown at higher magnification in Figure 2.
    Arterial embolus from Figure 1 at higher magnification, in an F344/N rat.
    Acute necrosis of the posterior colliculus, a bilaterally symmetrical lesion (arrows), in the whole mount of a section in a male F344/N rat from a 4-day study. This resulted from the selective vulnerability of this brain region to toxin-induced impaired energy metabolism. The arrowhead identifies necrosis of the nucleus of the lateral lemniscus.
    Similar regionally selective bilateral brain necrosis of the parietal cortex area 1 (blue arrow), thalamus (arrowhead), and retrosplenial cortex (white arrow) in a treated male F344/N rat from a 4-day study, all resulting from the same toxic compound as used in Figure 3.
    Unusual form of malacia (total regional necrosis) of the spinal cord in the dorsal spinal funiculi (arrow) in a female F344/N rat from a chronic study.
    A cortical infarct with gliosis and capillary hyperplasia (arrow) from a male B6C3F1 mouse in a chronic study.
    A more advanced stage of cortical infarction (arrows) in a treated female B6C3F1 mouse from a chronic chronic inhalation study.
    Morphology of an infarct of known duration (arrow) in an F344/N rat with experimental infarction.
    Later stage of cortical infarction, with loss of tissue and collapse of the cortical structure creating a depression at the meningeal surface (arrows), in a male F344/N rat from a chronic study.
    Detail of the cellular responses in cortical infarction of known 72-hour duration in an F344/N rat with experimental infarction. Note the hypertrophic and hyperplastic state of the capillary endothelium and the prominent macrophage presence (arrows).
    Olfactory bulb necrosis in a male B6C3F1 mouse from a chronic study. Note that the substance of the olfactory bulb is lost (arrows) as a result of marked tissue necrosis, leaving only cellular debris and hemorrhage.
    Necrotic hippocampal tissue as identified by microtubule-associated protein-2 immunohistochemistry, in a control female B6C3F1 mouse from a chronic study. The arrows demark the region of necrosis.


    Peter Little, DVM, MS, PhD, DACVP
    Neuropathology Consultant
    Experimental Pathology Laboratories, Inc.  
    Research Triangle Park, NC

    Deepa B. Rao, BVSc, MS, PhD, DABT, DACVP
    NTP Pathologist (Contractor)
    Integrated Laboratory Systems, Inc.
    Research Triangle Park, NC


    James P. Morrison, DVM, DACVP
    Scientific Director
    Charles River Laboratories, Pathology Associates
    Research Triangle Park, NC

    Robert C. Sills, DVM, PhD, FIATP
    Chief, Cellular and Molecular Pathology Branch
    National Toxicology Program
    National Institute of Environmental Health Sciences
    Research Triangle Park, NC