Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kyoto City, Kyoto 602-8566, Japan.
Neurosci Res. 2010 Apr;66(4):359-65. doi: 10.1016/j.neures.2009.12.006. Epub 2009 Dec 16.
The purpose of the present study was to determine whether murines could be substituted for traditional experimental mammals to study the brainstem mechanism of vocalization. We conducted systematic electrical and chemical stimulation of the brainstem in guinea pigs to identify the similarities in the call sites between murines and other mammals. We further examined whether or not fictive vocalization could be induced in paralyzed guinea pigs, an experimental model which facilitates neuronal recording in the brainstem. The sites where electrical stimulation evoked vocalization were distributed continuously from the periaqueductal grey (PAG) to the lower brainstem. This call area usually ended at the most caudal part of the inferior olive and thus did not continuously extend to the nucleus retroambiguus. Microinjections of d,l-homocysteic acid and bicuculline induced vocalization at the PAG, parabrachial nucleus, and the most dorsal part of the pontine reticular formation. The brainstem call areas and vocal motor patterns induced from these areas were approximately consistent with those in other mammals. Fictive vocalization induced by PAG stimulation could be identified from activities of the phrenic, abdominal, and superior laryngeal nerves in paralyzed guinea pigs. We thus concluded that guinea pigs can be utilized in studies of brainstem vocal mechanism.
本研究旨在确定是否可以用鼠类替代传统的实验用哺乳动物来研究发声的脑干机制。我们对豚鼠的脑干进行了系统的电刺激和化学刺激，以确定鼠类和其他哺乳动物发声部位的相似性。我们进一步研究了是否可以在麻痹的豚鼠中诱导出虚构的发声，这种实验模型有利于在脑干中进行神经元记录。电刺激诱发发声的部位从导水管周围灰质（PAG）连续分布到脑干下部。这个发声区域通常终止于下橄榄最尾端，因此不会连续延伸到疑核。D,L-同型半胱氨酸和荷包牡丹碱的微注射可在 PAG、臂旁核和脑桥网状结构的最背侧部分诱发发声。这些区域诱导的脑干发声区和发声运动模式与其他哺乳动物的大致一致。在麻痹的豚鼠中，PAG 刺激诱导的虚构发声可以从膈神经、腹肌和喉上神经的活动中识别出来。因此，我们得出结论，豚鼠可用于研究脑干发声机制。
