<prompt> Which intermediate of citric acid cycle is used in detoxification of ammonia in brain?CitrateSuccinateAlpha-ketoglutarateOxalo-acetate  <response>: When ammonia is present in body in large amount hyperammonemia, then this alpha-ketoglutarate of TCA combines with one amino group to form glutamate Fuher glutamate combines with the second amino group to form glutamine Glutamine is a safe form of ammonia storage transpo. Alpha-ketoglutarate is depleted, which affects TCA cycle. Thats why brain is affected as the first organ Brain is highly aerobic tissue. 