Cromwell H C, Berridge K C
Department of Psychology, University of Michigan, Ann Arbor 48109-1109, USA.
J Neurosci. 1996 May 15;16(10):3444-58. doi: 10.1523/JNEUROSCI.16-10-03444.1996.
The neostriatum and its connections control the sequential organization of action ("action syntax") as well as simpler aspects of movement. This study focused on sequential organization of rodent grooming. Grooming syntax provides an opportunity to study how neural systems coordinate natural patterns of serial order. The most stereotyped of these grooming patterns, a "syntactic chain," has a particularly stereotyped order that recurs thousands of times more often than could occur by chance. The purpose of the present study was to identify the crucial site within the striatopallidal system where lesions disrupt the syntax or serial order of syntactic grooming chains without disrupting constituent movements. Small excitotoxin lesions were made using quinolinic acid at bilateral sites within the dorsolateral, dorsomedial, ventrolateral, or ventromedial neostriatum, or in the ventral pallidum or globus pallidus of rats. An objective technique for mapping functional lesions was used to quantify cell death and to map precisely those lesions that disrupted grooming syntax. Our results identified a single site within the anterior dorsolateral neostriatum, slightly more than a cubic millimeter in size (1.3 x 1.0 x 1.0 mm), as crucial to grooming syntax. Damage to this site did not disrupt the ability to emit grooming actions. By contrast, damage to sites in the ventral pallidum and globus pallidus impaired grooming actions but left the sequential organization of grooming syntax intact. Neural circuits within this crucial "action syntax site" seem to implement sequential patterns of behavior as a specific function.
新纹状体及其连接控制着动作的顺序组织（“动作句法”）以及运动的更简单方面。本研究聚焦于啮齿动物梳理行为的顺序组织。梳理行为句法为研究神经系统如何协调序列顺序的自然模式提供了一个契机。这些梳理行为模式中最刻板的一种，即“句法链”，具有特别刻板的顺序，其重复出现的频率比随机出现的频率高出数千倍。本研究的目的是确定纹状体苍白球系统内的关键部位，在该部位进行损伤会破坏句法梳理链的句法或序列顺序，而不会破坏组成动作。使用喹啉酸在大鼠双侧的背外侧、背内侧、腹外侧或腹内侧新纹状体内，或腹侧苍白球或苍白球部位制造小的兴奋性毒素损伤。一种用于绘制功能性损伤的客观技术被用来量化细胞死亡，并精确绘制那些破坏梳理行为句法的损伤。我们的结果确定了前背外侧新纹状体内一个单一部位，大小略超过一立方毫米（1.3×1.0×1.0毫米），对梳理行为句法至关重要。损伤这个部位不会破坏发出梳理动作的能力。相比之下，损伤腹侧苍白球和苍白球部位会损害梳理动作，但梳理行为句法的序列组织保持完整。这个关键的“动作句法部位”内的神经回路似乎将行为的序列模式作为一种特定功能来实现。
