Burne T H, Rogers L J
Department of Physiology, University of New England, Armidale NSW, Australia.
Physiol Behav. 1996 Dec;60(6):1441-7. doi: 10.1016/s0031-9384(96)00300-9.
We have developed a method to measure responses to graded concentrations of volatile chemicals by domestic chicks (Gallus gallus domesticus). Concentration-response curves were obtained, from which 50% effective concentration (EC50) values were determined. One-day-old chicks were presented with a 4-mm diameter colored bead, at which they pecked readily, affixed to a tube containing log dilutions of odorant. The chick was exposed to the odorant when it pecked at the bead. Various methods of presentation were tried. The method preferred minimized the number of chicks required by allowing repeated testing. Habituation to visual cues was prevented by changing the color of the bead on each presentation. The number of pecks directed at the bead and the amount of head shaking that occurred while the chick was exposed to the stimulus during the 10-s trial were scored from video recordings. Chicks demonstrated increased amounts of head shaking with increasing concentrations of isoamyl acetate or allyl sulfide; low concentrations stimulated pecking and higher concentrations suppressed it. Coincident EC50 values for pecking and head shaking (approximately 1% for isoamyl acetate and allyl sulfide) indicate that they may be controlled by the same mechanism, albeit inversely. There was no relationship between the amount of pecking and the concentration of eugenol, but the EC50 value for head shaking was at the 30% concentration. The results demonstrate that one-day-old chicks show graded responses to graded concentrations of odors and that they demonstrate differential sensitivity to different odorants. Possible involvement of the trigeminal system in these responses is considered.
我们已经开发出一种方法来测量家鸡（Gallus gallus domesticus）对不同浓度挥发性化学物质的反应。获得了浓度-反应曲线，并据此确定了50%有效浓度（EC50）值。将一颗直径4毫米的彩色珠子固定在装有气味剂对数稀释液的管子上，给1日龄的雏鸡看，它们会很容易地啄珠子。当雏鸡啄珠子时，就会接触到气味剂。尝试了各种呈现方法。首选的方法通过允许重复测试将所需雏鸡的数量减到最少。每次呈现时改变珠子的颜色，以防止雏鸡对视觉线索产生习惯化。从视频记录中对雏鸡在10秒试验期间接触刺激时啄珠子的次数和摇头的次数进行评分。随着乙酸异戊酯或烯丙基硫醚浓度的增加，雏鸡摇头的次数增多；低浓度刺激啄食，高浓度则抑制啄食。啄食和摇头的EC50值一致（乙酸异戊酯和烯丙基硫醚约为1%），这表明它们可能受相同机制控制，尽管作用相反。啄食次数与丁香酚浓度之间没有关系，但摇头的EC50值在30%浓度处。结果表明，1日龄雏鸡对不同浓度的气味表现出分级反应，并且它们对不同气味剂表现出不同的敏感性。本文考虑了三叉神经系统在这些反应中可能的参与情况。
