To control the overall action of the body, brain consumes a large amount of energy in proportion to its volume. In
humans and many other species, the brain gets most of its energy from oxygen-dependent metabolism of glucose. An
abnormal metabolic rate of glucose and/or oxygen usually reflects a diseased status of brain, such as cancer or
Alzheimer’s disease. We have demonstrated the feasibility of imaging mouse brain metabolism using photoacoustic
computed tomography (PACT), a fast, noninvasive and functional imaging modality with optical contrast and acoustic
resolution. Brain responses to forepaw stimulations were imaged transdermally and transcranially. 2-NBDG, which
diffuses well across the blood-brain-barrier, provided exogenous contrast for photoacoustic imaging of glucose response.
Concurrently, hemoglobin provided endogenous contrast for photoacoustic imaging of hemodynamic response. Glucose
and hemodynamic responses were quantitatively unmixed by using two-wavelength measurements. We found that
glucose uptake and blood perfusion around the somatosensory region of the contralateral hemisphere were both
increased by stimulations, indicating elevated neuron activity. The glucose response amplitude was about half that of the
hemodynamic response. While the glucose response area was more homogenous and confined within the somatosensory
region, the hemodynamic response area showed a clear vascular pattern and spread about twice as wide as that of the
glucose response. The PACT of mouse brain metabolism was validated by high-resolution open-scalp OR-PAM and
fluorescence imaging. Our results demonstrate that 2-NBDG-enhanced PACT is a promising tool for noninvasive studies
of brain metabolism.