Neural mechanisms of Lombard reflex analyzed by experimental animal model.

Research Project

Project/Area Number	10671580
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Otorhinolaryngology
Research Institution	ASAHIKAWA MEDICAL COLLEGE
Principal Investigator	NOKAWA Satoshi Asahikawa Medical College, School of Medicine, Associate Professor, 医学部, 助教授 (50180758)
Project Period (FY)	1998 – 1999
Project Status	Completed (Fiscal Year 1999)
Budget Amount *help	¥2,700,000 (Direct Cost: ¥2,700,000) Fiscal Year 1999: ¥1,100,000 (Direct Cost: ¥1,100,000) Fiscal Year 1998: ¥1,600,000 (Direct Cost: ¥1,600,000)
Keywords	LOMBARD REFLEX / AUDITORY FEEDBACK / VOCALIZATION / DECEREBRATE CATS / SODIUM GLUTAMATE / THE DORSAL NUCLEUS OF THE LATERAL LEMNISCUS
Research Abstract	1) We analyzed that the neural mechamisms related to the Lombard reflex using experimental animal, that is decerebrate cats. During the PAG induced vocalization, the auditory stimulation increased the activities of intrinsic laryngeal and expiratory muscles. 2) First, the amplitude of laryngeal reflex evoked in the intrinsic laryngeal muscles increased during the auditory stimulation, which indicated that the activities of intrinsic laryngeal muscle motoneurons increased. 3) We administrated the sodium glutamate iontophoretically to the dorsal nucleus of the lateral lemniscus (LLD), which is one of auditory relay nucleus. After micro-administration, the amplitude of laryngeal reflex evoked in the laryngeal adductor muscle was increased. 4) We also clarified that the amplitude of L2 spinal cord reflex evoked in the external abdominal muscle was increased after micro-administration of sodium glutamate to the LLD. 5) These results suggested that the dorsal nucleus of the lateral lemniscus may be an essential relay in evocation of the auditory-laryngeal and auditory-spinal reflexes.