The relationship between consciousness and neuronal energy consumption and neurochemical signatures

Abstract

Background A close association exists between neuronal activity and blood flow/energy consumption in the brain. Functional brain imaging techniques allow real-time measurement of brain energy consumption and neurochemical signatures, and enable to reveal dynamic alterations of neuronal activity during state transition of brain functions, including consciousness and unconsciousness. Objective To investigate neuronal energy consumption and neurochemical signatures of consciousness and anesthetics-induced unconsciousness. Content The levels of energy consumption in the cerebrum are correlated with several neuronal substrates of consciousness, including gamma oscillations, global connections, and ratio of excitatory (glutamate) to inhibitory gamma-aminobutyric acid neurotransmitters, but the energy consumption in certain brain nuclei may not predict the states of consciousness. Anesthetics, including propofol, ketamine, and pentobarbital, can transform brain function from consciousness to unconsciousness by disrupting the coupling of energy consumption throughout cerebrum, and regulating release of glutamate, GABA, acetylcholine, lactate, glutamine in multiple brain regions. Trend The levels of neuronal energy consumption and neurochemicals are associated with the states of consciousness. The information would provide further insights towards a better understanding of neural substrates of cognitive activity and anesthesia. Key words: Neural energy; Neurochemistry; Consciousness; General anesthesia; Neuroimaging