Gozaine Teofilo C, Clark Keith F
Department of Otorhinolaryngology, the Oklahoma University Medical Center, Oklahoma City, OK, USA.
Laryngoscope. 2005 Jan;115(1):81-8. doi: 10.1097/01.mlg.0000150699.38753.74.
OBJECTIVES/HYPOTHESIS: The objective was to compare the activity of superior laryngeal nerve mechanoreceptors based on a respiration-based classification protocol with activities found using a vocalization-based classification protocol in adult cats.
Animal study.
In the first part of the experiment, single fiber action potentials from the internal branch of the superior laryngeal nerve were recorded in decerebrated cats using a respiration-based classification protocol to identify laryngeal mechanoreceptors as pressure, flow, and drive receptors, as described in the literature. A tracheal T-tube and a laryngeal mask airway were necessary modifications to perform this protocol. In the second part of the experiment, a vocalization-based classification protocol as described in the literature was used to classify the activity of the same fiber into the following groups: peak prephonatory, frequency-following, frequency-nonfollowing, inspiratory-modulated, or mixed. Vocalization was evoked by electrical stimulation of the midbrain in the region of the periaqueductal gray.
In all, eight cats were used for the experiment. Data were obtained from only three cats for a total of five single fibers. Results from five cats were not obtained because of inability to phonate (in three cats) and inability to record from the superior laryngeal nerve (in two cats). We identified two flow receptors, a drive receptor, a frequency-following receptor, and a frequency-nonfollowing receptor. Both flow receptor fibers were almost silent during the phonation phase and reached the maximum activity after vocalization during the inspiratory phase. The drive receptor was active during all four airway maneuvers and was most active during tracheal occlusion. It also kept a high level of activity during the phonatory phase, suggesting a role in the modulation of vocalization and respiration. The next two receptors, a frequency-following and a frequency-nonfollowing receptor, were active only during the phonatory phase and were totally inactive during the airway maneuvers, suggesting a role only during the vocalization behavior.
Because vocalization is an important stimulus for the activation of certain superior laryngeal nerve receptors, a classification protocol based on respiration alone is incomplete. Classification into pressure, flow, and drive receptors alone is not appropriate for the study of laryngeal receptors during vocalization. Some frequency-following and frequency-nonfollowing receptors may be active only during phonation and would otherwise be missed without vocalization stimuli.
目的/假设：目的是基于一种基于呼吸的分类方案，比较成年猫喉上神经机械感受器的活动与使用基于发声的分类方案所发现的活动。
动物研究。
在实验的第一部分，如文献所述，使用基于呼吸的分类方案，在去大脑的猫中记录来自喉上神经内支的单纤维动作电位，以将喉机械感受器识别为压力感受器、流量感受器和驱动感受器。气管T形管和喉罩气道是执行该方案所需的必要改良措施。在实验的第二部分，使用文献中描述的基于发声的分类方案，将同一纤维的活动分类为以下几组：发声前峰值、频率跟随、频率不跟随、吸气调制或混合。通过对中脑导水管周围灰质区域进行电刺激来诱发发声。
总共八只猫用于该实验。仅从三只猫获得了数据，共五条单纤维。由于无法发声（三只猫）和无法从喉上神经记录（两只猫），未获得五只猫的结果。我们识别出两个流量感受器、一个驱动感受器、一个频率跟随感受器和一个频率不跟随感受器。两条流量感受器纤维在发声阶段几乎不活动，在发声后的吸气阶段达到最大活动。驱动感受器在所有四种气道操作期间均活跃，在气管阻塞期间最为活跃。它在发声阶段也保持高水平活动，表明在发声和呼吸的调节中起作用。接下来的两个感受器，一个频率跟随感受器和一个频率不跟随感受器，仅在发声阶段活跃，在气道操作期间完全不活动，表明仅在发声行为期间起作用。
由于发声是激活某些喉上神经感受器的重要刺激，仅基于呼吸的分类方案是不完整的。仅将其分类为压力感受器、流量感受器和驱动感受器不适用于发声期间喉感受器的研究。一些频率跟随和频率不跟随感受器可能仅在发声期间活跃，否则在没有发声刺激的情况下会被遗漏。
