Clark R E, Zhang A A, Lavond D G
Department of Psychology, University of Southern California, Los Angeles 90089-2520, USA.
Neurobiol Learn Mem. 1997 Mar;67(2):96-111. doi: 10.1006/nlme.1996.3740.
Experiment 1 examined acquisition of the classically conditioned eyeblink response in rabbits (Oryctolagus cuniculus) during reversible cooling lesions of the cerebellar cortex (CX), facial nucleus (FN), or lateral parvocellular reticular formation (RF). Retention was then evaluated during periods of training during reversible cooling lesions and without cooling in rabbits that had acquired the conditioned response. We found that cooling the CX did not prevent acquisition, but did retard the acquisition rate. Cooling the FN during acquisition prevented the expression of the unconditioned and conditioned response, but did not prevent the acquisition when assessed during subsequent training without cooling. Cooling the RF had no effect on the acquisition or expression of the conditioned response. During subsequent retention testing, in well-trained animals, cooling the CX did not abolish the learned response. Cooling the FN abolished both the conditioned and the unconditioned response. The results from Experiment 1 indicate that the CX is more important for acquisition than retention of the conditioned response. The FN is not important for the acquisition of the conditioned response, but is essential for the expression of the conditioned and unconditioned response. Experiment 2 examined bilateral recordings from the cerebellum in well-trained rabbits, before and during interpositus or FN cooling. We found that cooling the interpositus abolished all learning related activity in the ipsilateral or contralateral cerebellum, but did not affect the stimulus evoked responses. Cooling the FN did not abolish stimulus evoked activity or learning related activity in the cerebellum. The results emphasize the critical importance of the ipsilateral cerebellum in classical eyeblink conditioning and suggest that the memory trace for this type of learning is mediated by unilateral circuitry.
实验1研究了在对家兔（穴兔）小脑皮质（CX）、面神经核（FN）或外侧小细胞网状结构（RF）进行可逆性冷却损伤期间，经典条件性眨眼反应的习得情况。然后，在已获得条件反应的家兔进行可逆性冷却损伤训练期间以及不进行冷却的训练期间，对记忆保持情况进行评估。我们发现，冷却CX并不妨碍习得，但会延缓习得速度。在习得过程中冷却FN会阻止无条件反应和条件反应的表现，但在随后不进行冷却的训练中评估时，并不妨碍习得。冷却RF对条件反应的习得或表现没有影响。在随后的记忆保持测试中，对于训练良好的动物，冷却CX并不会消除习得的反应。冷却FN会消除条件反应和无条件反应。实验1的结果表明，CX对条件反应的习得比记忆保持更为重要。FN对条件反应的习得并不重要，但对条件反应和无条件反应的表现至关重要。实验2在训练良好的家兔进行间位核或FN冷却之前和期间，对小脑进行双侧记录。我们发现，冷却间位核会消除同侧或对侧小脑中所有与学习相关的活动，但不影响刺激诱发反应。冷却FN并不会消除小脑中的刺激诱发活动或与学习相关的活动。结果强调了同侧小脑在经典眨眼条件反射中的关键重要性，并表明这种类型学习的记忆痕迹是由单侧神经回路介导的。
