2018/08/22
Keio University School of Medicine
Japan Agency for Medical Research and Development (AMED)
A joint research group—including Professor Hideyuki Okano (Team Leader, Laboratory for Marmoset Neural Architecture, RIKEN Center for Brain Science) and Project Assistant Professor Takahiro Kondo (Visiting Researcher, same laboratory) of the Department of Physiology, Keio University School of Medicine; Associate Professor Junichi Ushiba of the Department of Biosciences and Informatics, Faculty of Science and Technology; Risa Saito, a student in the Doctoral Programs at the Graduate School of Science and Technology; Masaki Otaka, a master's student at the time of the research; Associate Professor Kenji Tanaka of the Department of Neuropsychiatry, School of Medicine; and Associate Professor Mark Schnitzer of Stanford University—has, for the first time in the world, succeeded in visualizing deep-brain neural activity in freely behaving marmosets using a miniature fluorescence microscope.
Previously, two-photon microscopy has been used for large-scale measurement of deep-brain neural activity, but this required fixing the animal's head to the apparatus, making it impossible to measure neural activity during complex movements or social behaviors. The nVista from Inscopix, an ultra-compact fluorescence microscope weighing only 2g developed by co-researcher Associate Professor Schnitzer and his colleagues, allows for the measurement of deep-brain neural activity in freely behaving animals by implanting an endoscopic lens into the brain. Using this miniature fluorescence microscope, our research group successfully measured the activity of nerve cells deep in the motor cortex of the marmoset cerebral cortex (approximately 2000 μm from the brain surface) under freely behaving conditions. Furthermore, based on the patterns of individual neural activity measured, we were able to predict whether the marmoset would reach with its right or left hand.
This observation method using an endoscopic lens can also be applied to observe deeper brain regions such as the basal ganglia and hippocampus, making it a powerful tool for studying the neural networks involved in complex primate brain functions like movement, cognition, and memory. Furthermore, by applying this technique to marmoset models of psychiatric and neurological disorders, it is expected to lead to the development of new treatments for such disorders in humans.
The results of this research were published in Cell Reports on August 22 (JST).
Please see below for the full press release.