Olfactory bulb changes in Alzheimer's disease.

Olfactory bulbs in cases of Alzheimer's disease and age-matched controls have been examined by means of combining silver staining of pathological filaments with pigment-Nissl staining of the cell bodies. Neuritic plaques were found in the anterior olfactory nucleus. Neurofibrillary tangles and neuropil threads occurred in the anterior olfactory nucleus and in all layers of the olfactory bulb except the outer fibrous layer. The tangle-bearing neurons of the olfactory bulb were identified as tufted cells, outer granule cells, and two different types of nerve cells forming the rostral part of the anterior olfactory nucleus.