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Publisher Summary This chapter presents an outline of methods that are universal in the study of ultrastructure using examples that are specific to the central nervous system (CNS) and peripheral nervous systems (PNS). Subtle early structural changes of certain cellular organelles or structures may give an important clue as to the pathogenetic mechanisms of the effect of toxicants. For detailed morphological investigations, use of the electron microscopic technique is highly recommended. The procedural description is largely limited to the application of transmission electron microscopy (TEM), scanning electron microscopy (SEM), and a brief description of special methods. Artifacts of these methods are indicated. Special methods included are immunocytochemistry, enzyme cytochemistry, autoradiography, tracers, freeze-fracture, Golgi EM, and high voltage electron microscopy. This chapter discusses about fixatives that are required to prevent deterioration of ultrastructure, to add electron contrast to the tissue, and to harden the tissue for ultramicrotomy. Fixatives are composed of fixing agents, a buffer, and sometimes additives. The methods for tissue preparation for TEM, including fixation, dehydration, embedding, ultramicrotomy, staining, and microscopy are covered in detail in this chapter. |
