Department of Agrobiological Science, Faculty of Agriculture, Ehime University, Matsuyama 790-8566, Japan.
Department of Agrobiological Science, Faculty of Agriculture, Ehime University, Matsuyama 790-8566, Japan.
Comp Biochem Physiol A Mol Integr Physiol. 2022 Nov;273:111284. doi: 10.1016/j.cbpa.2022.111284. Epub 2022 Jul 30.
Infections frequently accompany with non-specific symptoms such as anorexia and hyperthermia. In addition, there may be unpleasant sensations such as visceral discomfort during infection. Lipopolysaccharide (LPS), a Gram-negative bacteria cell wall component, is known to induce the unpleasant sensation of conditioned taste aversion in mammals. However, the relationship between unpleasant sensations and changes in behavior and physiological conditions has not been investigated extensively in birds. Lithium chloride (LiCl) is a compound that induces unpleasant sensations, including visceral discomfort, although its effects on behavior and physiological conditions have also not been investigated extensively in birds. Thus, the present study was aimed to investigate the effect of an intraperitoneal (IP) injection of LiCl on conditioned visual aversion, food intake, cloacal temperature, voluntary activity, crop-emptying rate, and blood constituents in chicks (Gallus gallus). We also examined the effect of IP injections of LPS and zymosan, a cell wall component of fungus, on conditioned visual aversion formation. First, IP injection of LiCl was confirmed to induce conditioned visual aversion in chicks. An IP injection of LiCl significantly decreased food intake, voluntary activity, and crop-emptying rate but did not affect the temperature. In addition, the injection of LiCl significantly increased plasma corticosterone concentration, indicating that LiCl serves as a stressor in chicks. Finally, IP injections of LPS and zymosan were found to induce conditioned visual aversion in chicks. Collectively, these results suggest that LiCl induces conditioned aversion, anorexia, hypoactivity, and inhibition of crop-emptying in chicks. In addition, LPS and zymosan would induce unpleasant sensations in chicks.
感染常伴有厌食和发热等非特异性症状。此外，感染时可能会出现内脏不适等不愉快感觉。脂多糖（LPS）是革兰氏阴性细菌细胞壁的组成部分，已知它会在哺乳动物中引起条件性味觉厌恶的不愉快感觉。然而，在鸟类中，不愉快感觉与行为和生理状况的变化之间的关系尚未得到广泛研究。氯化锂（LiCl）是一种会引起不愉快感觉的化合物，包括内脏不适，尽管其对鸟类行为和生理状况的影响也尚未得到广泛研究。因此，本研究旨在研究腹腔内（IP）注射 LiCl 对小鸡（Gallus gallus）条件性视觉厌恶、食物摄入、泄殖腔温度、自愿活动、嗉囊排空率和血液成分的影响。我们还检查了 LPS 和真菌细胞壁成分酵母聚糖的 IP 注射对条件性视觉厌恶形成的影响。首先，证实 IP 注射 LiCl 可诱导小鸡产生条件性视觉厌恶。LiCl 的 IP 注射显著减少了食物摄入、自愿活动和嗉囊排空率，但对温度没有影响。此外，LiCl 的注射显著增加了血浆皮质酮浓度，表明 LiCl 对小鸡是一种应激源。最后，发现 LPS 和酵母聚糖的 IP 注射可诱导小鸡产生条件性视觉厌恶。总之，这些结果表明，LiCl 可诱导小鸡产生条件性厌恶、厌食、活动减少和嗉囊排空抑制。此外，LPS 和酵母聚糖会引起小鸡的不愉快感觉。
