The effect of ketamine upon norepinephrine and dopamine levels in rabbit brain parts.

Ketamine (40 mg/kg, i.v.) significantly increased dopamine levels in the thalamus and hypothalamus brain areas, but not in the midbrain or caudate nucleus. The increase in dopamine occurred during the time when ketamine produced its maximal anesthetic action (10-30 min). Ketamine had no effect upon norepinephrine levels in whole brain or the select brain parts with the exception of caudate nucleus at any of the times studied. These results demonstrate an effect of ketamine upon dopamine levels in those brain regions previously suggested as the site of ketamine's anesthetic action.