Morphological analysis of the control mechanisms of intrinsic laryngeal muscles during vocalization

2014 Fiscal Year Final Research Report

• Project/Area Number: 25861561
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Otorhinolaryngology
• Research Institution: Shimane University
• Principal Investigator: OKA Tatsuro 島根大学, 医学部, 助教 (20508923)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 発声 / 喉頭 / 疑核 / 疑核後核 / 中心灰白質 / 神経路標識法 / 神経回路 / ラット

Outline of Final Research Achievements

In the present study, to elucidate control mechanisms of intrinsic laryngeal muscles during vocalization, we examined the synaptic connections between the projection fibers from the periaqueductal gray (PAG) to the motoneurons that innervate intrinsic laryngeal muscle via medullary reticular formation by using anterograde and retrograde tract-tracing techniques. As a result, prominent overlapping distribution of the nucleus retroambiguus (NRA) axons and cricothyroid motoneurons was observed in the rostral part of the nucleus ambiguus. Furthermore, electron microscopic observation revealed that NRA terminals made asymmetrical synaptic contacts with cricothyroid motoneurons in the nucleus ambiguus. The present data, combined with previous studies, suggest that output signals from the PAG are transmitted disynaptically to the cricothyroid motoneurons via the NRA neurons for the control of vocalization.

Free Research Field

神経解剖学