Weinberger N M, Javid R, Lepan B
Center for the Neurobiology of Learning and Memory, University of California, Irvine 92625.
Proc Natl Acad Sci U S A. 1993 Mar 15;90(6):2394-8. doi: 10.1073/pnas.90.6.2394.
Brief learning experience (classical conditioning) induces frequency-specific receptive-field (RF) plasticity in the auditory cortex, characterized as increased response to the frequency of the conditioned stimulus and decreased responses to most other frequencies, including the pretraining best frequency. This experiment asked (i) whether learning-induced RF plasticity, established in the waking state, can be expressed under general anesthesia and if so (ii) whether it exhibits long-term retention. Pure-tone-frequency RFs were obtained from adult guinea pigs under general anesthesia (sodium pentobarbital or ketamine) before and repeatedly after (1 hr-8 weeks) a 20- to 30-trial session of pairing a non-best-frequency tone with mild footshock. Conditioned-stimulus-specific RF plasticity was expressed under both types of anesthesia and included shifts of the pretraining best frequency toward or even to the frequency of the conditioned stimulus. Moreover, this RF plasticity exhibits long-term retention, being evident 1-8 weeks after training. This satisfies a criterion for the long-term storage of information in the auditory cortex.
简短的学习经历（经典条件反射）会在听觉皮层中诱导频率特异性感受野（RF）可塑性，其特征是对条件刺激频率的反应增加，而对包括训练前最佳频率在内的大多数其他频率的反应减少。本实验探究了：（i）在清醒状态下建立的学习诱导RF可塑性在全身麻醉状态下是否能够表现出来，若能表现出来，（ii）其是否具有长期保持性。在成年豚鼠接受全身麻醉（戊巴比妥钠或氯胺酮）的情况下，在20至30次将非最佳频率纯音与轻度足部电击配对的试验之前和之后（1小时至8周）反复获取纯音频率RF。条件刺激特异性RF可塑性在两种麻醉类型下均有表现，包括训练前最佳频率向条件刺激频率甚至完全转变为条件刺激频率。此外，这种RF可塑性具有长期保持性，在训练后1至8周都很明显。这满足了听觉皮层中信息长期存储的一个标准。
