Influence of the cerebellar posterior vermis on the acquisition of the classically conditioned bradycardic response in the rabbit
Influence of the cerebellar posterior vermis on the acquisition of the classically conditioned bradycardic response in the rabbit
复制标题
小脑后蚓部对家兔获得经典条件性心动过缓反应的影响
DOI：
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发表时间：
2005
影响因子：
2
通讯作者：
B. Ghelarducci
中科院分区：
文献类型：
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作者：
L. Sebastiani;A. L. Noce;J. Paton;B. Ghelarducci
摘要：我们研究了手术切除不同小脑区域（小脑九小叶、后蚓或大脑半球）的兔的经典条件性心动过缓的程度。组织学显示病变局限于皮层和下层白质，对小脑深部核没有任何损害。在条件作用过程中，音调作为条件刺激（CS），耳震作为非条件刺激（US）。小脑病变不影响心动过缓定向反应、基线心率或无条件心动过速反应的特征。与对照组相比，切除后蚓的家兔的条件性心动过缓程度显著降低，而在第九小叶和半球病变家兔中则不受影响。通过条件作用，心动过缓反应的发展和适应的时间模式，以及它的地形，与任何损伤兔的对照组没有区别。在第一次条件训练后，一些对照兔被要求去除后蚓，然后按照相同的程序再次条件训练。他们在损伤前和损伤后的条件反应没有表现出任何明显的差异，并且与一组未操作的对照组所表现出的反应相似。由此可见，家兔小脑后蚓部参与了经典条件性心动过缓的初始习得，但不是其记忆痕迹的部位。
SummaryThe magnitude of classically conditioned bradycardia was studied in rabbits in which various cerebellar regions (lobule IX or the posterior vermis or the hemispheres) had been removed surgically. Lesions were shown histologically to be restricted to the cortex and the underlying white matter without any damage to the deep cerebellar nuclei. In the conditioning procedure, tones were employed as conditioned stimuli (CS) and ear shocks as unconditioned stimuli (US). Cerebellar lesions did not affect the characteristics of the bradycardic orienting response, baseline heart rate or the unconditioned tachycardic response to US. The conditioned bradycardia was significantly reduced in magnitude with respect to controls in rabbits submitted to removal of posterior vermis, while it was unaffected in lobule IX and hemispheric lesioned rabbits. The temporal pattern of development and habituation of the bradycardic response through the conditioning session, as well as its topography, did not differ from controls in any of the lesioned rabbits. After the first conditioning session, some control rabbits were submitted to removal of the posterior vermis and then conditioned again, following an identical procedure. Their pre- and post-lesion conditioned responses did not exhibit any appreciable differences and were similar to the responses exhibited by a group of unoperated controls which were submitted to a reconditioning session. It is concluded that in the rabbit the cerebellar posterior vermis is involved in the initial acquisition of the classically conditioned bradycardia, but it is not the site of its memory trace.