text: Additionally, experiments with the non-desensitizing site-directed mutant GluR3(L507Y) (Stern-Bach, Y., Russo, S., Neuman, M. and Rosenmund, C., A point mutation in the glutamate binding site blocks desensitization of AMPA receptors. Neuron, 21 (1998) 907-918) further confirms that << lithium >> enhances [[ GluR3 ]] responses by reducing desensitization, since lithium's effects are reversed in this mutant.