are useful for increasing levels of acetylcholine in neurons which contain acetylcholine and chat a preferred embodiment of all methods of the present invention is where the mammal to be administered a compound of formula i is a human particularly a female human and most particularly when that human female is estrogen deficient however human males are also contemplated under the term u201c mammal u201d particularly males who are testosterone deficient another preferred embodiment of the present invention is where the condition caused by a decrease of choline acetyltransferase and or acetylcholine in the frontal cortex and or hippocampus regions of the brain is alzheimer 39 s disease moreover a preferred embodiment of all methods of the present invention is the use of a compound of formula i where r 1 and r 2 are both the same alkyl radical r 3 is a lower alkyl radical r 4 is halo or a lower alkyl radical r 5 is h and n is 2 a more preferred embodiment of all the methods of the present invention is the use of a compound of formula i where r 1 and r 2 each are methyl r 3 is ethyl r 4 and r 5 each are h.