果蠅腦內機械感知神經網路圖譜

• Main Authors: Lou, Shyn-Jie, 羅士杰
• Other Authors: Chiang, Ann-Shyn
• Format: Others
• Language: en_US
• Online Access: http://ndltd.ncl.edu.tw/handle/69325539185623695765

碩士 === 國立清華大學 === 生物科技研究所 === 97 === To understand how a brain receive, compare, and process all kinds of sensory inputs, we have to identify every circuit involve in the processing pathway. By using Drosophila as a model system to study brain function, the olfactory system is the most popular topic and became a clearly understood system. However, little was known in other sensory pathway in the Drosophila brain. Mechanosensory system is involved in sensing sound, wind and gravity. Here, we study the mechanical sensory and processing circuits included auditory circuits and wind sensing circuits. All of these mechanosensory neurons were located in the secondary segment of antenna, called the Johnston’s organ (JO), detecting signals and projecting axonal terminals to a specific brain region--the antennal mechanosensory and motor center (AMMC). The signals are thus relayed from the antennae into the brain. Although the auditory circuits at the first level of are well known, the processing center at the next level is unclear in the Drosophila brain. In this study, we utilize the PaGFP technique to search candidate circuits involved in mechanical signal processing at the second level. Then, we used functional imaging to verify these candidate circuits do response to mechanostimulus. In this study, we found a bilateral neuron connect one side of the AMMC and send to the both side of caudo-ventrolateral protocerebrum (CVLP) regions indicating that the CVLP may act as a second level of mechanosensory center correspondence to the mushroom body in the Drosophila olfactory system. We further found four types of morphological distinct neurons innervate the CVLP region, one may act as local regulatory neurons and others receive signals and send to three different parts of higher brain regions. Taken together, our finding show the mechanosensory information is converged to the CVLP and diverged to at least three parts of higher brain regions. These will help us to understand how the mechaosensory circuits are constructed and signals processed in the Drosophila brain.