Oral physiological study on respiration center in vocalization

当发声时，动物以特殊的发声方式停泊。为了阐明呼吸方式转换的神经机制，大鼠提供了一个很好的模型，因为大鼠在中央灰质等发声中心受到电刺激时会发出可听的超声声。首先，我们记录了幼鼠和成年大鼠的呼吸运动和发声。在幼崽中，超声波发声与出生后一天、两天和十天内强烈的呼气运动有关。发出的声音用超声分析仪分析，非常接近20 kHz左右的纯音。观察切断返神经和膈神经对声学发声的影响。半切不能有效地阻止发声。然而，切断两侧神经并没有给我们带来恒定的发声效果。在成人中，中央灰质或周围区域的刺激可引起超音化发声，并对其进行超声分析。可听到的声音类似于尖叫声，而超声波类似于纯音。成年犬在发射超声波时的呼吸运动与幼犬不同。成虫呼气缓慢，发出超声波，而幼崽呼气强烈。切断成人的返神经或膈神经不会引起超声波发射。本研究没有阐明发声时控制呼吸的直接神经中枢，但可以明确发声与呼吸运动的关系，以及周围神经系统在发声中的作用。

When vocalizing, animals berath in the special way for vocalization. To elucidate the neural mechanism of switching the way of breathing, rat offers a good model because rat emits audible- and ultra-sounds when it is stimulated electrically in vocal center like central gray. Firstly we recorded respiratory movement and vocalized sounds in pups and adult rats. In pups the ultrasound vocalization was associated with strong expiratory movement in one, two, and ten days after birth. Emitted sounds were analyzed by sonagraph, which was very close to about 20 kHz pure tone. The effects of cutting recurrent and phrenic nerve on ultrasound vocalization were examined. Hemisection was not effective to stop vocalization. However, the cutting in both sides of nerves did not give us the constant results in vocalization. In adults the stimulation of central gray or surrounding area caused audible of ultra sound vocalizations, which were analyzed by sonagraph. Audible sounds were similar to screams while ultrasounds were like pure-tone. The respiration movement in adult when emitting ultrasounds was different from one in pups. Adults expirated slowly with ultrasound emission while pups did strongly. Cutting the recurrent or phrenic nerves in adults caused no ultrasound emission. The study did not elucidate direct neural center which controles respiration in vocalization, but could make clear the relationship between vocalization, and respiratory movement, and the function of peripheral neural system in vocalization.