Abstract: The present invention generally relates to the treatment and/or prevention of Alzheimer's disease, other neurodegenerative diseases, and/or diseases characterized by the presence of certain metal ions, by using certain compositions including organosilicon compounds. A composition of the invention may be administered to a mammal, such as a human. In some cases, the composition may include a silanol, a silandiol, a silantriol, or a cyclic organosilane, and/or be able to form a silanol, a silandiol, or a silantriol upon exposure to physiological conditions such as are found in the blood, in the stomach and/or gastrointestinal tract, or in the brain or other organ. In certain cases, the organosilicon compound may be bound to a moiety able to be transported across the blood-brain barrier into the brain, for example, an amino acid, a peptide, a protein, a virus, etc. The organosilicon compound may also be labeled (e.g., fluorescently or radioactively) in certain instances.