Glutamate is the most abundant excitatory neurotransmitter in the brain, and it plays an essential and important role in neural functions. Hypofunction of the glutamatergic pathway and the changes in the glutamate-glutamine cycle function are important neuropathological mechanisms of severe mental disorders including schizophrenia and depression. Current studies have shown that glutamate can induce neural biophotonic activity and transmission, which may involve the mechanism of photon quantum brain; however, it is unclear whether such a mechanism follows the principle of quantum mechanics. Here we show that the action of glutamate on its receptors leads to a decrease in its quantum energy levels, and glutamate then partially or completely loses its function to further induce the biophotonic activity in mouse brain slices. The reduced quantum energy levels of glutamate can be restored by direct-current electrical discharges and the use of energy transfer of chloroplast photosynthesis; hence, the quantum energy recovered glutamate can again induce significant biophotonic activity. Furthermore, the changes in quantum energy levels of glutamate are related to the exchange and transfer of electron energy on its active hydrogen atom. These findings suggest that the glutamate-induced neural biophotonic signals may be involved in the transfer of the quantum energy levels of glutamate, which implies a quantum mechanism of neurotransmitter action. The process of glutamate recycling that is related to the synergism of neurons and glial cells and certain key enzymes may be necessary for the recovery of quantum energy levels of glutamate after completion of the neural signal transmission. These findings may also provide a new idea to develop "quantum drugs".