<prompt> Ketamine acts an which receptorGABAAGABABNMDAGlutamate  <response>: Ketamine has multiple effects throughout the central nervous system, and it is well recognized to inhibit N-methyl-D-aspaate NMDA channels and neuronal hyperpolarization-activated cationic HCN1 channels. Ref: Morgan Mikhails clinical anesthesiology 6e 