UPLC-MS/MS-based profiling of 31 neurochemicals in the mouse brain after treatment with the antidepressant nefazodone

Depression, typically understood as a mental disorder, is characterized by monoamine neurotransmitter de-ficiencies in the central nervous system (CNS). A majority of antidepressants have been developed to increase endogenous levels of monoamine neurotransmitters, such as dopamine (DA), norepinephrine (NE), and serotonin (5-HT) in brain tissue. Increasingly, the critical effects of a variety of neurotransmitters, including those of the dopaminergic, serotonergic, kynurenergic, cholinergic, histaminergic, and GABAergic systems, as well as several amino acids, have been spotlighted as neuromodulators over the years in various behavioral and emotional responses. In the present study, we developed a simple method for simultaneous analysis of 31 neurochemicals in mouse whole brain tissue using liquid chromatography tandem mass spectrometry (LC-MS/MS). Our neuro-chemical profiles were classified into seven categories according to metabolic pathways composed of neuro-transmitters and their precursors or metabolites. The analytical method was validated by intra-and inter-day precision, accuracy, sensitivity, and selectivity, and finally applied for neurochemical profiling in the mouse brain following nefazodone treatment. In this study, the modulation of 5-HT and DA by nefazodone was confirmed in the mouse brain, as previously reported. Interestingly, nefazodone-induced broad-spectrum neurochemical changes could suggest that nefazodone has novel anti-depressive and anti-cholinesterase potency via increasing endogenous levels of betaine and acetylcholine in the mouse brain. This neurochemical profiling approach may represent a meaningful tool for better understanding brain neurochemistry and neurotoxicity in discovery and development of CNS drugs.