It's a salt of carbonic acid. it's called sodium bicarbonate. It contains the anion HCO3. It usually refers to bicarbonate of soda (baking soda), a white powder that is a common ingredient in antacids. It is also a byproduct of your body's metabolism.
A bicarbonate is a salt containing the anion HCO3-, which is the most important buffer in the blood, it is regulated by the kidney, which excretes it in excess and retains it when needed; it increases with ingestion of excess anti-acids, diuretics and steroids; it is decreased with diarrhoea, liver disease, renal disease and chemical poisoning.
The changes in memory and personality occur in people with Alzheimer's disease is that they lose the ability to do common things that require basic mental processing. They could have great memory loss and personality or behavoir change.