Hashemzadeh Mona, Zendehdel Morteza, Babapour Vahab, Panahi Negar
a Department of Basic Sciences, Faculty of Veterinary Medicine, Science and Research Branch , Islamic Azad University , Tehran , Iran.
b Department of Basic Sciences, Faculty of Veterinary Medicine , University of Tehran , Tehran , Iran.
Int J Neurosci. 2018 Apr;128(4):361-368. doi: 10.1080/00207454.2017.1383908. Epub 2017 Dec 18.
The present study was designed to examine the role of central γ-Aminobutyric acid receptors and dopaminergic system on feeding behaviour in neonatal layer-type chicken.
In this study, six experiments were designed, each with four treatment groups (n = 44 in each experiment). In experiment 1, four groups of 3-h food-deprived chicks received a dose of either the intracerebroventricular injection of (1) control solution, (2) Levo-dihydroxyphenylalanine as precursor of dopamine; 125 nmol, (3) Gaboxadol (γ-Aminobutyric acid receptor agonist, 0.2 µg) and (4) Levo-dihydroxyphenylalanine (125 nmol) plus Gaboxadol (0.2 µg). Experiments 2-6 were similar to experiment 1, except that the chickens were intracerebroventricular-injected with 6-hydroxydopamine (is a neurotoxin; 2.5 nmol), SCH23390 (D receptor antagonist, 5 nmol), AMI-193 (D2 receptor antagonist, 5 nmol), NGB2904 (D receptor antagonist, 6.4 nmol) and L-741,742 (D receptor antagonist, 6 nmol) instead of levo-dihydroxyphenylalanine. Then, the cumulative food intake was measured until 120 min post-injection.
According to the results, intracerebroventricular injection of Gaboxadol (0.2 µg) significantly increased the food intake (P < 0.05). Co-injection of the 6-hydroxydopamine + Gaboxadol significantly amplified the food intake (P < 0.05). Intracerebroventricular injection of SCH23390 (5 nmol) + Gaboxadol (0.2 µg) significantly amplified the Gaboxadol-induced hyperphagia (P < 0.05). No significant effect was observed by co-injection of the D-D receptor antagonists + Gaboxadol (P > 0.05).
These results suggested the interconnection between central Dopaminergic and γ-Aminobutyric acid on the feeding behaviour mediates via D and γ-Aminobutyric acid receptors in 3-h food-deprived neonatal layer-type chicken.
本研究旨在探讨中枢γ-氨基丁酸受体和多巴胺能系统在新生蛋鸡采食行为中的作用。
本研究设计了六个实验，每个实验有四个处理组（每个实验n = 44）。在实验1中，四组禁食3小时的雏鸡接受以下剂量的脑室内注射：（1）对照溶液；（2）左旋二羟基苯丙氨酸（多巴胺前体，125 nmol）；（3）加波沙朵（γ-氨基丁酸受体激动剂，0.2 μg）；（4）左旋二羟基苯丙氨酸（125 nmol）加加波沙朵（0.2 μg）。实验2至6与实验1相似，不同之处在于雏鸡脑室内注射的是6-羟基多巴胺（一种神经毒素，2.5 nmol）、SCH23390（D受体拮抗剂，5 nmol）、AMI-193（D2受体拮抗剂，5 nmol）、NGB2904（D受体拮抗剂，6.4 nmol）和L-741,742（D受体拮抗剂，6 nmol），而不是左旋二羟基苯丙氨酸。然后，测量注射后120分钟内的累计采食量。
结果显示，脑室内注射加波沙朵（0.2 μg）显著增加了采食量（P < 0.05）。6-羟基多巴胺与加波沙朵联合注射显著增加了采食量（P < 0.05）。脑室内注射SCH23390（5 nmol）加加波沙朵（0.2 μg）显著增强了加波沙朵诱导的摄食亢进（P < 0.05）。D-D受体拮抗剂与加波沙朵联合注射未观察到显著影响（P > 0.05）。
这些结果表明，在禁食3小时的新生蛋鸡中，中枢多巴胺能系统和γ-氨基丁酸之间通过D和γ-氨基丁酸受体介导的相互联系对采食行为产生影响。
