title: Methodology for studying cerebral evoked potentials challenged.
mesh_terms: D000698:Analgesia; D001921:Brain / Q000502:physiology*; D005071:Evoked Potentials; D006801:Humans; D009609:Nitrous Oxide; D010146:Pain / Q000209:etiology* / Q000503:physiopathology; D014070:Tooth / Q000294:innervation
chemical_list: D009609:Nitrous Oxide