Area changes in slices of rat brain during preparation for histology or electron microscopy

Abstract

Cerebral slices cut from rat brain, either 2-3 mm or 0.27 mm thick, were used to study the effect of embedding and freezing. Paraffin wax sections 6 micrometer thick were mounted and stained with haematoxylin and eosin or Marsland et al.'s (1954) silver stain, and their areas were examined at each step. Embedding in paraffin wax of slices 2-3 mm thick, or in Epon of slices 0.27 mm thick, caused a diminution of their areas by 20-30%. Staining of paraffin wax sections did not alter their areas. Glycerol alone at 15% concentration had no effect on the areas, but at 30% concentration they were diminished by approximately 20%. Diminution of the areas of glycerol treated slices 0.27 mm thick also occurred when they were transferred to liquid N2 or to isopentane, but the areas increased after glycerol was replaced by Freon 12. It was concluded that embedding or freezing cerebral slices caused changes in their areas, but that staining of sections after they had been embedded, sectioned and mounted did not.

Morphology of human neutrophils: A comparison of cryofixation, routine gluteraldehyde fixation, and the effects of dimethyl sulfoxide

“…Greater shrinkage of cells was observed with GO treatment, consistent with results described for other cell types (Hillman and Deutsch, 1978;Lee, 1984;Lee et al, 1982). This shrinkage was observed Fig.…”

“…Morphometric methods have been used to measure (linearly) tissue shrinkage with glutaraldehyde fixation of mouse ova and demonstrated approximately a 3% decrease in diameter and up to a 12% decrease when embedded in Epon (Konwinski et al, 1974). Hillman and Deutsch (1978) reported a 20-30% decrease in tissue cross-sectional areas of rat brain with glutaraldehyde fixation and ethanol dehydration. Similarly, cell volume changes of 10-30% were reported in cultured rat smooth muscle tissue (Lee et al, 1982).…”

Ultrastructural localization of the norepinephrine transporter in superficial and deep layers of the rat prelimbic prefrontal cortex and its spatial relationship to probable dopamine terminals

“…It should be noted that the distance measurements reported in the present investigation are given for relative quantitative purposes only, as there is likely to be tissue shrinkage during the processing for immunocytochemistry and electron microscopy (Hillman and Deutsch, 1978). Furthermore, the relationship between NET-ir and TH-ir profiles was examined only in coronal sections, and this relationship might vary in different planes of section.…”

Ultrastructural localization of the serotonin transporter in superficial and deep layers of the rat prelimbic prefrontal cortex and its spatial relationship to dopamine terminals

“…Profiles outside the 13.8 m 2 field (i.e., profiles greater than 3.7 m apart) were not accounted for by this method. Furthermore, a certain degree of tissue shrinkage probably occurred, as a portion of the extracellular space is not preserved during fixation and processing of the brain for electron microscopy (Hillman and Deutsch, 1978). However, from the paucity of TH-ir and SERT-ir profiles that were directly apposed to one another, the current findings suggest that the two types of varicosities are separated on average by at least 1.30 m. Finally, it should be noted that the current observations were made in single coronal planes of section.…”