Neuroanatomical Effects of Aluminum

Increased brain aluminum accumulation is known to be associated with neurofibrillary tangles in some species. The terms neurofibrillary tangle or neurofibrillary degeneration refer to an accumulation of tangles of neurofibers within the neuron. Electron microscopic examination of aluminum-induced neurofibrillary tangles indicates that they consist of areas of cytoplasmic clearings, filled with either compact orderly bundles or accumu- 

90 xeiTy and Pena and Wisniewski et al. report that these 10 nm filaments sometimes appear to have a hollow lu- 

Neurochemical analysis of the neurofilaments in the aluminum-induced tangles indicates that they are composed of three proteins with molecular weights of 68,000, 160,000, and 200,000 daltons. The protein bands from the aluminum-induced neurofilaments were significantly augmented at 68,000 and 160,000 

Not all animals, however, develop neurofibrillary degeneration. The rat, for example, does not develop neurofibrillary tan-gles, even at doses 5-6 times that adequate for the cat (see below for further discussion). 

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