A method for treating Alzheimers Disease (AD) or Autism Spectrum Disorder (ASD) by administering at least one alky ester of imidazolecarboxylc acid, preferably methyl 4-imidazolecarboxylate. It is hypothesized that the treatment counters AD/ASD by maintaining the intracellular/extracellular osmolyte gradient in the central nervous system (CNS) within a substantially normal range. The methyl 4-imidazolecarboxylate may be administered orally, by inhaler, by injection or by transdermal application. When administered by transdermal application, the dosage range may be from about 0.01 mcg per day to about 3.0 mcg per day, preferably from about 0.1 mcg per day to about 0.3 mcg per day.