Kilpatrick I C, Collingridge G L, Starr M S
Neuroscience. 1982 Jan;7(1):207-22. doi: 10.1016/0306-4522(82)90161-0.
The gamma-aminobutyrate-containing nature of nigrotectal neurones and the possible involvement of the tectum in circling behaviour were investigated in the rat. Electrolytic or kainic acid lesions of the substantia nigra reduced gamma-aminobutyrate levels on average by 19-29% in intermediate and deep, but not superficial superior colliculus. Placement of lesions or injection of muscimol (40 ng) into these gamma-aminobutyrate-innervated layers of superior colliculus gave only weak ipsilateral posturing or circling that was intensified by apomorphine, but which strongly antagonized contraversive apomorphine-induced circling in 6-hydroxydopamine pretreated rats(lateral greater than medial sites). Contraversive circling to unilateral muscimol (40 ng) was significantly attenuated by lesions or muscimol injections placed in the ipsi- or contralateral superior colliculus. Picrotoxin (40 ng) and tetanus toxin (30 mouse LD50 doses) evoked explosive motor behaviour from medial colliculus and vigorous contraversive circling when injected into the lateral colliculus. The latter offset ipsiversive asymmetries to kainate (0,8 micrograms) in the corresponding substantia nigra. Bilateral intratectal picrotoxin produced hyperactivity that reversed haloperidol catalepsy. Similar bilateral administration of muscimol did not produce catalepsy but a state of frozen immobility. Kainic acid introduced into the superior colliculus gave mixed excitatory-inhibitory responses initially followed by ipsiversive circling only and loss of tectal perikarya. None of these drug effects occurred from the overlying cerebral cortex or subjacent tegmentum. We propose that separate medial "non-postural" and lateral "postural" tectal locomotor regions may exist in the superior colliculus that are situated within a striato-nigrotectal outflow system capable of influencing the animal's motor activity and posture.
在大鼠中研究了黑质-顶盖神经元中含γ-氨基丁酸的性质以及顶盖可能参与转圈行为的情况。黑质的电解损伤或 kainic 酸损伤平均使中脑顶盖中间层和深层而非表层的γ-氨基丁酸水平降低19% - 29%。在这些由γ-氨基丁酸支配的中脑顶盖层放置损伤或注射蝇蕈醇（40 ng）仅产生微弱的同侧姿势或转圈，阿扑吗啡可增强这种反应，但在经6-羟基多巴胺预处理的大鼠中（外侧部位大于内侧部位），其强烈拮抗阿扑吗啡诱导的对侧转圈。向同侧或对侧中脑顶盖放置损伤或注射蝇蕈醇可显著减弱对单侧蝇蕈醇（40 ng）的对侧转圈。印防己毒素（40 ng）和破伤风毒素（30个小鼠半数致死量）注入外侧中脑顶盖时可从中脑内侧诱发爆发性运动行为和强烈的对侧转圈。后者可抵消相应黑质中对 kainate（0.8微克）的同侧不对称反应。双侧脑内注射印防己毒素可产生多动，逆转氟哌啶醇诱导的僵住症。类似地，双侧注射蝇蕈醇不产生僵住症，但产生一种静止不动的状态。将 kainic 酸引入中脑顶盖最初产生混合的兴奋-抑制反应，随后仅出现同侧转圈以及顶盖神经核周体的丧失。这些药物效应均未出现在上方的大脑皮层或下方的被盖区。我们提出，中脑顶盖可能存在独立的内侧“非姿势性”和外侧“姿势性”顶盖运动区域，它们位于一个能够影响动物运动活动和姿势的纹状体-黑质-顶盖流出系统内。
