Use of reduced silver staining to show loss of connections in aged rat brain

A variation of the Fink-Heimer reduced silver technique was used to show the extent of axonal degeneration in the brains of aged rats. Degeneration product was extensive throughout the white matter of the old brains, being most dense in the optic tract, but substantial in fornix, corpus callosum, cingulum, and anterior commissure. There was selective impregnation of hippocampal strata, suggesting that there may be differential atrophy of connections as a function of age.