Photoacoustic imaging of functional domains in primary motor cortex in rhesus macaques

Functional detection in primate brains has particular advantages because of the similarity between non-human primate brain and human brain and the potential for relevance to a wide range of conditions such as stroke and Parkinson's disease. In this research, we used photoacoustic imaging (PAI) technique to detect functional changes in primary motor cortex of awake rhesus monkeys. We observed strong increases in photoacoustic signal amplitude during both passive and active forelimb movement, which indicates an increase in total hemoglobin concentration resulting from activation of primary motor cortex. Further, with PAI approach, we were able to obtain depthresolved functional information from primary motor cortex. The results show that PAI can reliably detect primary motor cortex activation associated with forelimb movement in rhesus macaques with a minimal-invasive approach.