Uwano T, Nishijo H, Ono T, Tamura R
Department of Physiology, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Japan.
Neuroscience. 1995 Sep;68(2):339-61. doi: 10.1016/0306-4522(95)00125-3.
Neuronal activities were recorded from the amygdala and amygdalostriatal transition area of behaving rats during discrimination of conditioned auditory, visual, olfactory, and somatosensory stimuli associated with positive and/or negative reinforcements. Neurons were also tested with taste solution and various sensory stimuli that were not associated with reinforcement. Of the 1195 neurons tested, 475 responded to one or more sensory stimuli. Of these, 256 neurons responded exclusively to a unimodal sensory stimulus, 128 to multimodal sensory stimuli, and the remaining 91 could not be classified. Distribution of unimodal neurons was correlated with anatomical projections to the amygdala from sensory thalamus or sensory cortices. Multimodal neurons were located mainly in the basolateral and central nuclei of the amgydala. Response latencies of neurons in the basolateral nucleus were longer than those in other nuclei and neurons in the central nucleus had both short and long latencies. Neurons responsive to a given stimulus were more frequently encountered in the amygdalas of the trained rats than in those of the rats not trained to associate that stimulus with a reinforcement. Multimodal neurons that responded to conditioned and/or unconditioned stimuli used in the associative learned tasks were concentrated in the basolateral and central nuclei. The results indicate that some amygdalar neurons receive exclusive single sensory information, and the others receive information from two or more sensory inputs. Considering the long latencies and multimodal responsiveness, the basolateral and central nuclei of the amygdala might be foci where various kinds of sensory information converge. It is also suggested that the basolateral and central nuclei of the amygdala have critical roles in associative learning to relate sensory information to reinforcement or affective significance.
在对与正性和/或负性强化相关的条件性听觉、视觉、嗅觉和体感刺激进行辨别期间，从行为大鼠的杏仁核和杏仁核纹状体过渡区记录神经元活动。还用味觉溶液和各种与强化无关的感觉刺激对神经元进行测试。在测试的1195个神经元中，475个对一种或多种感觉刺激有反应。其中，256个神经元仅对单峰感觉刺激有反应，128个对多峰感觉刺激有反应，其余91个无法分类。单峰神经元的分布与从感觉丘脑或感觉皮层到杏仁核的解剖投射相关。多峰神经元主要位于杏仁核的基底外侧核和中央核。基底外侧核中神经元的反应潜伏期比其他核中的长，中央核中的神经元既有短潜伏期也有长潜伏期。与未训练将该刺激与强化联系起来的大鼠相比，在训练大鼠的杏仁核中更频繁地遇到对给定刺激有反应的神经元。对联想学习任务中使用的条件性和/或非条件性刺激有反应的多峰神经元集中在基底外侧核和中央核。结果表明，一些杏仁核神经元仅接收单一感觉信息，而其他神经元接收来自两种或更多种感觉输入的信息。考虑到长潜伏期和多峰反应性，杏仁核的基底外侧核和中央核可能是各种感觉信息汇聚的焦点。还表明，杏仁核的基底外侧核和中央核在将感觉信息与强化或情感意义联系起来的联想学习中起关键作用。
