In addition to analyzing the full spectrum of antipsychotic and antidepressant drugs and metabolites, other naturally occurring compounds such as amino acids (e.g., serine and glycine), neurotransmitters (e.g.,norepinephrine, dopamine) and neuromodulators (e.g.,kynurenic acid, quinolinic acid) are of increasing interest. As part of a collaborative study, his lab had recently been selected to perform a preliminary pharmacokinetic study on an experimental antipsychotic to correlate brain imaging response with plasma drug levels. Similarly, salvinorin, a potent recreational hallucinogenic drug is being studied to determine various behavioral, cognitive and neuroendocrine effects during a pharmacokinetic interval. These assays were developed and validated using liquid chromatography-mass spectroscopy, a highly sensitive and specific procedure. Finally, a number of studies involving the drug ketamine are on-going in an effort to explain its rapid antidepressant response in humans.