"Touch sensory maps and circuits in mice."Fang Wang(Tsinghua University)-2010.7.17
报告题目：Touch sensory maps and circuits in mice
报告人：Fang Wang 博士(Tsinghua University)
报告简介：In many mammalian species, prominent neural structures with shapes and organizations mirroring exactly the specialized sensory organs are formed in the somatosensory cortex. The molecular mechanisms that allow peripheral organs to impinge patterns onto the brain are not well understood. Somatosensory neurons that connect sensory organs to the brain play a key first step in this process. We studied how trigeminal sensory neurons form modular structures called barrelettes that map the tactile whiskers onto the brainstem in mice. We found that whisker-derived retrograde TGFβ signaling is required for appropriate formation of barrelettes. Deletion of Smad4, a common transducer of TGFβ signals, selectively in sensory neurons results in abnormal barrelettes in the nucleus of Principalis and Interpolaris, as well as a complete lack of barrelettes in the nucleus of Caudalis. These defects are caused by mis-projections and incomplete segregations of trigeminal central axons representing neighboring whiskers. Our work provides clear evidence that in the somatosensory system, peripheral organ-derived molecular signals play a key role in organizing the formation of discrete neural structures according to the patterns of sensory organs.