Scanning electron microscopy of the central nervous system. I. The cerebellum.

The fine structure of the cerebellar cortex has been studied by means of scanning electron microscopy (SEM). The neuropil is revealed by careful tearing of aldehyde-fixed tissue specimens which are prepared by means of dehydration, critical point freeze-drying, and sputter-coating with gold-palladium. Specimens are subsequently viewed at magnifications of up to X 16,000 with capabilities for extension up to about X 40,000. The technique provides remarkable three-dimensional views of neuropil including cell bodies and dendrites, details of presynaptic and postsynaptic morphology, axonal structure, neuroglia, and the microvasculature. It seems particularly powerful in demonstrating relationships between neuropil elements such as the terminal synaptic array on neuron somata and the arrangements of structures on membrane surfaces.