Oral physiological study on respiration center in vocalization

动物在发声时，会以特殊的方式下潜。为了阐明转换呼吸方式的神经机制，老鼠提供了一个很好的模型，因为老鼠在中央灰色等声音中枢受到电刺激时会发出可听和超声音。首先，我们记录了幼鼠和成年鼠的呼吸运动和发声。在出生后1、2和10天，超声发声与强烈的呼气运动有关。发出的声音通过超声波分析，非常接近20千赫左右的纯音。观察切断膈神经和返神经对超声发声的影响。半切不能有效停止发声。然而，两侧神经的切割并没有给我们带来恒定的发声结果。对成人中枢灰质或周围区域的刺激可引起可听的超声发声，并进行超声分析。可听到的声音类似于尖叫声，而超声波则像纯音。在发出超声波时，成年犬的呼吸运动与幼犬不同。成年犬在超声发射下缓慢呼气，而幼崽呼气强烈。切断成人返神经或膈神经无超声发射。该研究没有阐明在发声过程中直接控制呼吸的神经中枢，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过程中的作用。

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.