ABSTRACT
All aspects of the nervous system are potential therapeutic targets and are potentially susceptible to injury by drugs, chemicals, vectors, devices, large molecules, and monoclonal antibodies. For many preclinical studies, evaluation of the nervous system is limited to the brain, spinal cord, and a peripheral nerve. Different types of nervous cells used for diagnosis are neurons, astrocytes, oligodendrocytes, microglial cells, ependyma, Schwann Cells, and satellite glial cells. There are three barriers that selectively isolate portions of the nervous system from exogenous and endogenous molecules/chemicals. These barriers are the blood brain barrier (BBB), the BCSFB, and the blood–nerve barrier (BNB). The peripheral components of the nervous system are frequently under sampled. Many drugs affect autonomic functions, but few studies even look at this portion of the nervous system. The most common pigments encountered within neurons are lipofuscin, which is golden yellow and generally associated with aging, and neuromelanin, which is most commonly noted in the hypothalamic neurons.
