Kejia Cai1, Mohammad Haris1, Anup Singh1, Feliks Kogan1, Walter R.T. Witschey1, Prianka Waghray1, Joel H. Greenberg2, Hari Hariharan1, John A. Detre2, Ravinder Reddy1
1CMROI, Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States; 2Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
Glutamate (Glu) is the major neurotransmitter for fast excitatory synaptic transmission in central nervous system (CNS). Traditional magnetic resonance spectroscopy (MRS) for detection of Glu generally provides poor spatial and temporal resolution. This study demonstrates that Glu exhibits a pH-dependent chemical exchange saturation transfer (CEST) effect (GluCEST) in a concentration dependent manner. Glu modulation via intravenous injection in a rat brain tumor model resulted in clear elevation of GluCEST. Future studies using this approach may provide new insights into Glu function and demonstrate its potential as a biomarker for CNS disorders.