Further support for the importance of glutamate in brain energy metabolism comes from a study that measured cerebrospinal fluid (CSF) amino acid concentrations and the activity of two transaminases, glutamic oxaloacetate transaminase (AST) and glutamic pyruvate transaminase (ALT), in human Alzheimer’s disease (AD) and a normal brain. The gene discussed is GOT1; the disease is early-onset autosomal dominant Alzheimer disease.