Approaching auditory circuit development using Hox mutant mouse

2014 Fiscal Year Final Research Report

• Project/Area Number: 24700336
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Neuroscience in general
• Research Institution: Nagoya Bunri University
• Principal Investigator: NARITA Yuichi 名古屋文理大学, 健康生活学部, 准教授 (40360614)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: Hox / 聴覚回路 / トノトピー / 発生

Outline of Final Research Achievements

In auditory circuit, sound information from the inner ear is transmitted to the cochlear nucleus (CN) via spiral ganglion (SG) neurons. The connection between these components is organized topographically in frequency-specific manner. But very little has been known how the development of topographic connection is organized. Hox genes are well known for AP axis patterning during early development, but recent evidence suggests their roles in establishment of topographic circuitry. We found that Hoxa2 and b2 are strongly expressed in the mouse CN from the beginning of its formation. Thus, we analyzed the morphological, functional, and molecular consequences of conditional deletion of Hoxa2 and Hoxb2 in CN. We identified SG projection in Hoxa2/Hoxb2 cKO targets significantly broader area in CN both morphologically and functionally. These results suggest a role of Hox genes in tophographic connectivity ensuring precision of sound transmission in the auditory circuit.

Free Research Field

神経発生生物学