Northmore D P, Levine E S, Schneider G E
Department of Psychology, University of Delaware, Newark 19716.
Exp Brain Res. 1988;73(3):595-605. doi: 10.1007/BF00406619.
Syrian golden hamsters were implanted with fixed or moveable stimulating electrodes aimed at the superior colliculus (SC). Behavior was observed in response to trains of 0.1 ms pulses at 200 Hz while the animals were moving freely in an open arena or in their home cages. At threshold stimulating currents, the responses consisted almost entirely of freezing or contraversive turning, which occurred in two forms: fast turns, resembling orienting movements to sunflower seeds, and slow turns that were smooth and continuous. Other responses, including head raising and lowering, ipsiversive turning and backing movements were seen occasionally. Increasing the stimulating current usually gave a variety of responses, including circling movements, prolonged freezing, ipsilateral movements and running escape behavior. The sites in SC giving freezes at threshold tended to be located superficially (SO and above), or deep (SGP and below), while sites giving turns were in the intermediate layers. Most freeze sites occurred in the rostro-medial SC that represents the upper visual field, while turn sites occurred predominantly in caudo-lateral SC. Apart from the turns, most of the stimulated responses resembled natural defensive behavior, supporting the view that SC in rodents plays a role in organizing responses to predators, as well as in orienting behavior.
将固定或可移动的刺激电极植入叙利亚金黄地鼠的上丘（SC）。当动物在开放场地或其笼舍中自由活动时，观察它们对200Hz的0.1ms脉冲串的行为反应。在阈值刺激电流下，反应几乎完全由僵住或反向转身组成，有两种形式：快速转身，类似于对葵花籽的定向运动，以及缓慢、平滑且持续的转身。偶尔还会观察到其他反应，包括抬头和低头、同侧转身和后退运动。增加刺激电流通常会引发多种反应，包括转圈运动、长时间僵住、同侧运动和逃跑行为。在阈值时引发僵住反应的上丘部位往往位于浅层（上丘层及以上）或深层（深层灰质层及以下），而引发转身反应的部位则在中间层。大多数引发僵住反应的部位出现在代表上视野的吻内侧上丘，而引发转身反应的部位主要出现在尾外侧上丘。除了转身反应外，大多数受刺激引发的反应类似于自然防御行为，这支持了啮齿动物的上丘在组织对捕食者的反应以及定向行为中起作用的观点。
