ABSTRACT
The xenobiotic and/or possible metabolites may enter the nervous system; the extent of entry will be dependent upon the effectiveness of the molecules of concern in penetrating the blood-brain and blood-nerve barriers. Electrophysiological techniques offer one of the best-suited approaches to the objective and specific assessment of nervous system function. Morphological examination of the nervous system can range in sophistication from gross examination of postmortem or biopsy specimens to stereologic quantitation of fine structure. Specimens of peripheral nerve fixed and processed for plastic embedding can instead be placed in a low viscocity resin such as Spurr’s medium and individual myelinated fibers dissected from a fascicle with fine needles. Concurrent measurement of axonal conduction velocity can establish whether changes in sensory responsiveness are due to toxicity of the nerve axon or to a selective loss of the nerve terminal.
