Majak Katarzyna, Pitkänen Asla
Epilepsy Research Laboratory, Department of Neurobiology, A.I. Virtanen Institute for Molecular Sciences, University of Kuopio, PO Box 1627, FIN-70211 Kuopio, Finland.
Eur J Neurosci. 2003 Sep;18(6):1652-9. doi: 10.1046/j.1460-9568.2003.02854.x.
Several studies implicate a role for the amygdala in processing of emotional memories that might partially occur in the connections between the amygdala and the hippocampal-parahippocampal areas. The present study was designed to determine if the pathway from the amygdala to the entorhinal cortex becomes activated during acquisition of fear-conditioning. First, the retrograde tracer Fluoro-Gold (FG) was iontophoresed into the entorhinal cortex in rats. Following habituation, animals were divided into five groups: (i) controls that received another habituation session; (ii) animals given a tone only; (iii) animals given a footshock only; (iv) animals given an unpaired presentation of a shock and a tone; and (v) conditioned animals that received a single tone-footshock pairing. Then double-immunohistochemistry against c-Fos and FG or glutamate decarboxylase (GAD67) was performed. The numbers and densities of labelled neurons were calculated in the lateral and basal nuclei of the amygdala. In conditioned animals the number and density of c-Fos-positive nuclei increased in dorsolateral and medial divisions of the lateral nucleus compared with the control group (P < 0.05). Additionally, in the medial division of the lateral nucleus, the percentage of c-Fos/FG double-labelled neurons was higher in the conditioned animals compared with the other groups (P < 0.05). Only a very few GAD67-positive interneurons expressed c-Fos. These data indicate that a part of the amygdalo-entorhinal pathway is activated during acquisition of fear-conditioning. These data support the idea that emotionally relevant sensory information in the lateral nucleus can influence information processing in the hippocampal and parahippocampal areas via the amygdalo-entorhinal pathway.
多项研究表明，杏仁核在处理情绪记忆中发挥作用，这一过程可能部分发生在杏仁核与海马旁海马区之间的连接中。本研究旨在确定在恐惧条件反射习得过程中，从杏仁核到内嗅皮质的通路是否会被激活。首先，将逆行示踪剂荧光金（FG）通过离子电渗法注入大鼠的内嗅皮质。适应后，将动物分为五组：（i）接受另一次适应训练的对照组；（ii）仅给予音调的动物；（iii）仅给予足部电击的动物；（iv）给予电击和音调非配对呈现的动物；以及（v）接受单次音调 - 足部电击配对的条件反射动物。然后进行针对c-Fos和FG或谷氨酸脱羧酶（GAD67）的双重免疫组织化学。计算杏仁核外侧核和基底核中标记神经元的数量和密度。与对照组相比，条件反射动物外侧核背外侧和内侧分区中c-Fos阳性核的数量和密度增加（P < 0.05）。此外，在外侧核的内侧分区中，条件反射动物中c-Fos/FG双标记神经元的百分比高于其他组（P < 0.05）。只有极少数GAD67阳性中间神经元表达c-Fos。这些数据表明，在恐惧条件反射习得过程中，杏仁核 - 内嗅通路的一部分被激活。这些数据支持这样一种观点，即外侧核中与情绪相关的感觉信息可通过杏仁核 - 内嗅通路影响海马和海马旁区域的信息处理。
