The skull of mice is thin and transparent. Therefore, cortical activities are easily visualized using endogenous flavoprotein fluorescence signals reflecting the activity-dependent changes in oxidative metabolism in mice. We are investigating cortical activities in the auditory, visual and somatosensory cortices using this technique. However, there are higher association cortices between these primary sensory areas, and their functions are largely unknown in mice. In general, neurons in the association cortices respond to various stimuli, and therefore, may be involved in association (integration) of information. Another point is that some neural activities in the association cortices can be maintained after stimulus offset, suggesting that they are related to certain types of short-term memory. Integration of information and short-term memory are important elements of consciousness, so that the associative cortices are likely related to consciousness. Generally speaking, consciousness research is not easy in the framework of falsifiable scientific studies in mice. Fortunately, we have found a particular strain of mice that exhibit specific and simultaneous impairment of sensory integration and short-term memory. Using these mice, we are now challenging to investigate the neural mechanisms of consciousness in the framework of falsifiable scientific studies.
|Assoc. Prof.||Ryuichi HISHIDA|