Shohamy D, Allen M T, Gluck M A
Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, Newark 07102, USA.
Behav Neurosci. 2000 Oct;114(5):867-74.
This study used anatomical cues to suggest a functional dissociation between the roles of the entorhinal cortex and the hippocampus in learning. The authors proposed that the highly convergent inputs to the entorhinal cortex indicate this region may be particularly important for selecting or compressing information. This hypothesis was tested in rabbits (Oryctolagus cunniculus) trained on an associative learning task that is a common index of stimulus selection. In this task, known as latent inhibition, preexposure to a stimulus (such as a tone) leads to slowed learning when the same tone is subsequently paired with an outcome (such as an airpuff to the eye). As hypothesized, rabbits with neurotoxic lesions of the entorhinal cortex failed to show slowed learning following preexposure (no latent inhibition) and learned the association faster than control rabbits. In contrast, hippocampal-lesioned animals showed normal (slowed) learning.
本研究利用解剖学线索，提示内嗅皮层和海马体在学习过程中的作用存在功能分离。作者提出，高度汇聚至内嗅皮层的输入表明该区域可能对选择或压缩信息尤为重要。这一假设在接受关联学习任务训练的家兔（穴兔）身上进行了测试，该任务是刺激选择的常用指标。在这个被称为潜伏抑制的任务中，对一种刺激（如音调）进行预暴露，当相同音调随后与一个结果（如向眼睛吹气）配对时，会导致学习速度减慢。正如所假设的那样，内嗅皮层有神经毒性损伤的家兔在预暴露后没有表现出学习速度减慢（无潜伏抑制），并且比对照家兔更快地学会了这种关联。相比之下，海马体损伤的动物表现出正常（减慢）的学习。
