Nervous System and Special Sense Organs

Proliferative and Nonproliferative Lesions of the Rat and Mouse Central and Peripheral Nervous Systems

“…For example, F344 rats given bis(4-amino-3-methylcyclohexyl)methane, an amine-curing agent for epoxy resin, develop varying degrees of vacuolar change in the choroid plexus due to water uptake and, less frequently, lamellar inclusion bodies (Shibata et al 1990). Treatment with diisobutamide, a piperidine ring compound with antiarrhythmic activity, induces marked vacuolation of the choroid plexus epithelium as well as many peripheral organs in rats (and to a lesser degree in dogs and monkeys) due to intralysosomal accumulation of lamellated phospholipid inclusions (myelin figures; Koizumi et al 1986;Greaves 2000;Johanson et al 2011). …”

“…The ventricles and central canal are lined by ependymal cells. The ventricles (especially the lateral and fourth chambers) contain prominent tufts of choroid plexus, which is specialized to generate cerebrospinal fluid (CSF; Johanson et al 2011); choroid plexus epithelial cells are also predilection sites for a number of systemic disorders (Greaves 2000). The circumventricular organs are six special neuronal aggregates located in close proximity to the ependymal lining of the ventricular system (Garman 2011).…”

“…Although many industrial and environmental chemicals have been shown to directly destroy CNS neurons (Greaves 1990), preclinical toxicity studies describing neuronal cell loss in rats and mice are relatively rare. Neuronal cell loss has been induced in rats by carotid artery ligation (Bendel et al 2005) and by treatment with trimethyltin (Little et al 2002;Philbert, Billingsley, and Reuhl 2000) or neurotoxic analogs of excitatory amino acids that activate ionotropic glutamate receptors, such as kainic acid (Liang et al 2007).…”

International Harmonization of Nomenclature and Diagnostic Criteria (INHAND): Nonproliferative and Proliferative Lesions of the Dog

“…Ophthalmoscopic examination of eyes with tapetal degeneration typically shows loss of tapetal reflectivity with the development of focal, mottled, or diffuse zones of pigmentation. 210 Spontaneous focal tapetal degeneration in untreated dogs may rarely be seen, 211 but it is more likely to occur as a treatment-related change. It has been reported following administration of a number of different classes of therapeutic agents.…”

“…It has been reported following administration of a number of different classes of therapeutic agents. 210,212,213 Due to the absence of a tapetum lucidum in humans, tapetal changes in dogs without alterations in other structures of the eye may not be relevant for humans.…”