演題詳細
Poster
嗅覚、味覚、化学感覚
Olfaction, Taste, Chemical Senses
開催日 | 2014/9/12 |
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時間 | 14:00 - 15:00 |
会場 | Poster / Exhibition(Event Hall B) |
5T4は嗅球介在ニューロンにおいて神経活動依存的に樹状突起の発達を促進する
5T4 glycoprotein regulates the sensory experience-dependent dendritic development of olfactory bulb interneurons
- P2-160
- 高橋 弘雄 / Hiroo Takahashi:1 吉原 誠一 / Sei-ichi Yoshihara:1 小川 陽一 / Yoichi Ogawa:2 木下 雅仁 / Masahito Kinoshita:1 西村 信城 / Nobushiro Nishimura:1 坪井 昭夫 / Akio Tsuboi:1
- 1:奈良医大・脳神経システム / Lab for Mol Biol of Neural System, Nara Med Univ, Kashihara, Japan 2:奈良医大・第一生理 / Dep. of Physiol. I, Nara Med Univ, Kashihara, Japan
Sensory input has been shown to regulate development in a variety of species and in various structures, including the retina, cortex and olfactory bulb (OB). Within the mammalian OB specifically, the development of dendrites in mitral/tufted cells is well known to be odor-evoked activity-dependent. However, little is known about the developmental role of sensory input in the other major OB population of the GABAgenic interneurons, such as granule cells and periglomerular cells. Recently, we identified, with DNA microarray and in situ hybridization screenings, a trophoblast glycoprotein 5T4 gene, whose expression in the OB interneurons is dependent on sensory experience (Yoshihara et al., J. Neurosci. 32, 2217, 2012). 5T4 is a type I transmembrane protein, whose extracellular domain contains seven leucine-rich repeats, and seems to function in the Wnt-noncanonical pathway. 5T4-knockout mice resulted in a significant reduction in the dendritic branching of OB granule cells. Further, 5T4 overexpression could rescue the reduction of the dendritic branching in its knockout granule cells.
To know the physiological role of 5T4 in dendritic development of OB granule cells, we conducted behavior tests for 5T4-knockout mice. Interestingly, 5T4-knockout mice were defective in the odor detection thresholds and impaired the acquisition of the two-related-odor discrimination task, but not the olfactory detection ability in the food seeking task. Taking account of electrophysiological study for OB granule cells in 5T4-knockout mice, these results demonstrate that 5T4 contributes to regulate the sensory experience-dependent dendritic development of interneurons and the formation of functional neural circuitry in the OB (Takahashi et al., submitted).