| 日 時 | 2022年03月04日(金) 14:00 より 15:00 まで |
|---|---|
| 講演者 | 渡我部 昭哉 博士 |
| 講演者所属 | 理研CBS |
| 場 所 | OCC２階小会議室（オンサイト）および オンライン(Zoom) |
| お問い合わせ先 |
窪田芳之 生理学研究所 yoshiy@nips.ac.jp |
| 要旨 | The expansion of the prefrontal cortex (PFC) is a hallmark of primate brain evolution. Whereas the increase in the number of neurons leads to the formation of more complex neural circuits, the burden of wiring costs becomes more severe. Here we propose a model of "population connectivity" that may explain the neural architecture of the enlarged cortex. In our group, we use marmosets as a primate model for a projectome analysis of the PFC. In this study, we have succeeded in quantitatively describing the complex projection patterns of the PFC by classifying them into two types: one is the focal type, in which axon terminals are concentrated in a narrow region of a submillimeter scale, and the other is the spread type, in which projections are sparse but spread over a wide area. The projection from each point of the PFC is thought to be a mixture of both and can be explained by a topographic model based on the injection coordinate. Functionally, these two types of projections involve different populations of neurons with differential effects. The focal type is responsible for localized and highly efficient neurotransmission, while the spread type would be effective only when neural activity is widespread and synchronized. Comparison with mouse data suggests that the refinement of the population connectivity may have been an important factor in enabling efficient neurotransmission in the enlarged primate cortex. |
