Penna M, Capranica R R, Somers J
Section of Neurobiology and Behavior, Cornell University, Ithaca, New York 14853.
J Comp Physiol A. 1992 Jan;170(1):73-82. doi: 10.1007/BF00190402.
Twenty four castrated male, 6 intact male, and 11 intact female Hyla cinerea were injected subcutaneously with 25 micrograms arginine-vasotocin (AVT) and induced to call 1 h later in response to the playback of a conspecific mating call. Eighteen castrated males and 8 intact females were implanted 5 mg androgen pellets for 3 weeks prior to the neuropeptide injection. Among castrated males, 6/9 testosterone (T) implanted, 4/9 dihydrotestosterone (DHT) implanted and 2/6 non implanted individuals produced calls after being administered AVT. 5/6 intact non implanted males and 6/8 T intact implanted females also called, and 3 intact non implanted females remained silent after the injection. Evoked calls had a mid-frequency spectral peak at about 1900 Hz which is absent in field-recorded mating calls of this species. Calls of implanted females and castrated non implanted males were shorter than those of castrated implanted and intact non implanted males. Audiograms measured before hormone implants showed dips of enhanced sensitivity at about 0.5, 0.9 and 3.0 kHz in males and females. After AVT injection, thresholds at frequencies within the 0.7-1.5 kHz range were increased in castrated males. Such reduction in sensitivity points to an inhibition of the auditory system during hormone induced vocal activation.
将24只去势雄蛙、6只未去势雄蛙和11只未去势雌蛙灰树蛙皮下注射25微克精氨酸血管加压素（AVT），1小时后，在播放同种交配叫声的刺激下诱导其鸣叫。在注射神经肽前3周，给18只去势雄蛙和8只未去势雌蛙植入5毫克雄激素丸粒。在去势雄蛙中，植入睾酮（T）的9只中有6只、植入双氢睾酮（DHT）的9只中有4只以及未植入的6只中有2只在注射AVT后发出叫声。6只未植入的未去势雄蛙中有5只以及8只植入T的未去势雌蛙中有6只也发出了叫声，3只未植入的未去势雌蛙在注射后保持沉默。诱发叫声在约1900赫兹处有一个中频频谱峰值，而该物种野外记录的交配叫声中没有这个峰值。植入雌蛙和去势未植入雄蛙的叫声比去势植入雄蛙和未植入未去势雄蛙的叫声短。在植入激素前测量的听力图显示，雄蛙和雌蛙在约0.5、0.9和3.0千赫处有灵敏度增强的下降。注射AVT后，去势雄蛙在0.7 - 1.5千赫范围内的频率阈值升高。这种灵敏度的降低表明在激素诱导的发声激活过程中听觉系统受到了抑制。
