Lowndes M, Davies D C
Department of Anatomy, St. George's Hospital Medical School, Cranmer Terrace, Tooting, London, UK.
Behav Brain Res. 1995 Dec 14;72(1-2):25-32. doi: 10.1016/0166-4328(95)00026-7.
The chick archistriatum has been implicated in avoidance learning and filial imprinting. However, its role in these learning paradigms may be due to the inhibition of normal avoidance responses, since the avian archistriatum has been shown to play a role in fear/avoidance behaviour. The involvement of the archistriatum in the expression of unlearned fear/avoidance behaviour was therefore investigated in two day-old chicks. Chicks were exposed individually to a novel 'open field' for 5 min. Behaviour was recorded on videotape for analysis. In a separate but concurrent experiment, bilateral archistriatal lesions, sham archistriatal lesions or lateral cerebral lesions were made in day-old chicks which were then exposed to the 'open field' arena. At the end of each exposure a novel object was dropped near the chick. Chicks with archistriatal lesions generally displayed greater movement, more pecking behaviour and spent more time near the centre of the 'open field' than other chicks. There were no differences between the treatment groups in latencies to move or begin peeping. The behaviour of untreated chicks in the 'open field' was similar to that of sham-lesioned chicks and there was no effect of hatch on behaviour. Upon exposure to a novel object, indices of fear and avoidance were not changed in lesioned chicks. These results demonstrate that in the young chick, the archistriatum may be involved in the response to mild or intermediate levels of environment or isolation-related stress, but does not appear to be important for overt fear responses or avoidance of novel objects. Taken together with the results of previous work, the data suggests that the archistriatum may be directly involved in avoidance learning and imprinting.
鸡的古纹状体已被认为与回避学习和亲子印记有关。然而，它在这些学习模式中的作用可能是由于抑制了正常的回避反应，因为鸟类的古纹状体已被证明在恐惧/回避行为中起作用。因此，在两日龄的雏鸡中研究了古纹状体在未学习的恐惧/回避行为表达中的作用。将雏鸡单独置于一个新的“旷场”中5分钟。行为被记录在录像带上以供分析。在另一个同时进行的实验中，对两日龄的雏鸡进行双侧古纹状体损伤、假古纹状体损伤或大脑外侧损伤，然后将它们置于“旷场”场地中。在每次暴露结束时，在雏鸡附近扔下一个新物体。与其他雏鸡相比，有古纹状体损伤的雏鸡通常表现出更多的活动、更多的啄食行为，并且在“旷场”中心附近停留的时间更长。各处理组在移动或开始鸣叫的潜伏期方面没有差异。未处理的雏鸡在“旷场”中的行为与假损伤雏鸡相似，孵化对行为没有影响。在接触新物体时，损伤雏鸡的恐惧和回避指标没有变化。这些结果表明，在幼雏鸡中，古纹状体可能参与对轻度或中度环境或与隔离相关的应激的反应，但对于明显的恐惧反应或回避新物体似乎并不重要。结合先前工作的结果，数据表明古纹状体可能直接参与回避学习和印记。
