Miyata Mariko    Department   School of Medicine, School of Medicine    Position   Professor and Division head
Language	English
Title	Somatotopic refinement via developing synapse elimination in the whisker sensory thalamus of developing mice
Conference	Saitama Univ. Neuroscience Seminar
Invitation	Invitation
Presentation Type	Speech
Lecture Type	Special/Invited Lecture
Publisher and common publisher	◎Mariko Miyata
Date	2013/06/25
Venue (city and name of the country)	Saitama, Japan
Summary	Synapse elimination and strengthening are critical steps for the developmental organization of neural circuit. Afferent synapses in the whisker sensory thalamus undergo developmental synapse elimination even after the whisker map called barreloid is established. However, the physiological meaning in the detail is unclear because what fiber is going to survive and what is not, is poorly characterized.Thus,we generate Krox20Cre:td Tomato transgenic mice in which whisker-related afferent(lemniscal) fibers are specifically labeled. Then, we studied the developmental synapse elimination of the lemniscal fibers in the somatosensory thalamus using the mice. Here we show that non-whisker-related lemniscal fibers were preferentially eliminated in the developing whisker sensory thalamus. Such preferential elimination was more prominent on dendrites than on soma of relay neurons, and was partially dependent on tactile sensory experience. Synaptic maturation coincided with this process, indicating selective strengthening of surviving afferent synapses. Our results imply one of the functional significances of the synapse elimination,refinement of somatotopic information in the developing sensory thalamus.