A. neural degeneration may occur too early for scientists to be able draw many useful conclusions about it
B. a loss of neurons would be undetectable unless the deadcellswere concentrated in a particular area of the brain
C. pathologists not only were researching the wrong stage of the disease process, but ignoring its unique effects on different species
D.the brain tends through its natural processing to remove the effects of neural degeneration
E. the theories of Aldrich and Mignot were largely correct, at least as far as dogs are concerned