xc- activity has been shown to significantly affect glutamate levels as knock-out mice for Slc7a11 have decreased levels of extracellular glutamate.20,21 Gene deletion leads to minor spatial memory deficits,20,47 and impaired hippocampal LTP47 and acute inhibition of xc- is associated with anxiety-related behaviors.49 Inactivation of the glial glutamate transporter GLAST, which likely leads to an increase of extracellular glutamate, also leads to endophenotypes that are associated with schizophrenia such as memory deficits and impaired acoustic startle.47 This evidence concerns the gene SLC1A3 and Anxiety.