INTRINSIC NEURONS IN THE AMYGDALOID FIELD PROJECTED TO BY THE MEDIAL GENICULATE-BODY MEDIATE EMOTIONAL RESPONSES CONDITIONED TO ACOUSTIC STIMULI
INTRINSIC NEURONS IN THE AMYGDALOID FIELD PROJECTED TO BY THE MEDIAL GENICULATE-BODY MEDIATE EMOTIONAL RESPONSES CONDITIONED TO ACOUSTIC STIMULI
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DOI：
10.1016/0006-8993(86)90020-x
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发表时间：
1986-09-24
期刊：
影响因子：
2.9
通讯作者：
REIS, DJ
中科院分区：
文献类型：
--
作者：
IWATA, J;LEDOUX, JE;REIS, DJ
在之前的实验中，我们在大鼠对声刺激的情绪反应的经典调节中涉及从内侧膝状体（MG）到皮层下区域的投射，涉及后尾壳核和杏仁核的部分。在本系列实验中，我们检查了皮层下区域的内在神经元是否介导情绪调节，如果是的话，关键神经元是否包含在杏仁核或尾壳核内。对大鼠进行单侧 MG 电解损伤。相反，通过显微注射鹅膏蕈酸破坏皮层下区域的内在神经元。这种病变组合使 1 个 MG 和 1 个皮层下区域保持完整，但已断开。对照组接受单侧磷酸盐缓冲剂注射到 MG 病变对侧的皮层下区域，或不进行手术。两周后，对动物进行连续的、计算机辅助记录的动脉压和心率，并进行经典的条件反射试验，包括呈现与足部电击相关的纯音。对于假条件对照组来说，与音调有关的电击的发生是随机的。在消退试验中评估了由音调引起的平均动脉压、心率和情绪行为（“冻结”）的条件性变化。实验完成后，处死大鼠，并使用标准程序取出它们的大脑并切片。在基于计算机的图像处理系统的帮助下评估病变位置和大小。在未经手术的条件反射大鼠中，声刺激引起动脉压和心率增加，并引起冻结。条件反射大鼠和假条件反射大鼠的动脉压和冻结反应不同，但心率反应没有差异。因此，只有动脉压和冻结反应反映了音调和休克之间关联的形成。单侧 MG 病变对侧皮层下区域内在神经元的破坏破坏了动脉压和冻结反应的关联调节。这些的幅度降低到在假条件大鼠中观察到的水平。非相关性心率变化不受病变影响。鹅膏蕈酸破坏了内在神经元并保留了皮层下区域的纤维，这一点在解剖学和生物化学上得到了证明。因此，由 MG 支配的皮层下区域中的内在神经元似乎介导联想情绪调节。为了确定关键的联合神经元是否包含在杏仁核或尾壳核内，准备了额外的动物，使其具有单侧 MG 损伤，并在后尾壳核或杏仁核中对侧注射鹅膏蕈酸。尾壳核注射对任何反应都没有影响。相比之下，杏仁核注射要么破坏动脉压和冻结反应，要么只破坏冻结反应，要么对两者都没有影响。杏仁核注射并没有减少心率变化。那些没有影响的杏仁核细胞损伤明显小于破坏一种或两种反应的损伤。两种反应均被破坏的亚组中细胞损失的区域一致涉及眼底纹状体（杏仁核的壳核部分）和杏仁核的底层中央核。仅破坏冻结反应的损伤集中在杏仁核的外侧核和中央核的外侧部分。无效的病变不是……
In previous experiments we implicated projections from the medial geniculate body (MG) to a subcortical field, involving portions of the posterior caudate-putamen and amygdala, in the classical conditioning of emotional responses to acoustic stimuli in the rat. In the present series of experiments we examined whether intrinsic neurons in the subcortical field mediate emotional conditioning and, if so, whether the critical neurons are contained within the amygdala or the caudate-putamen. Rats were prepared with a unilateral electrolytic lesion of the MG. Contralaterally, intrinsic neurons were destroyed in the subcortical field by microinjection of ibotenic acid. This lesion combination leaves one MG and one subcortical field intact but disconnected. Controls received unilateral injection of phosphate buffer vehicle into the subcortical field contralateral to the MG lesion or were unoperated. After two weeks the animals were instrumented for continuous, computer-assisted recording of arterial pressure and heart rate and subjected to classical conditioning trials involving the presentation of a pure tone in association with foot-shock. The occurrence of the shock with respect to the tone was random for a pseudoconditioned control group. Conditioned changes in mean arterial pressure, heart rate and emotional behavior (‘freezing’) elicited by the tone were assessed during extinction trials. Following completion of the experiments, the rats were sacrificed and their brains were removed and sectioned using standard procedures. Lesion location and size was evaluated with the assistance of a computer-based image processing system. In unoperated conditioned rats the acoustic stimulus elicited increases in arterial pressure and heart rate, and induced freezing. The arterial pressure and freezing responses differed in conditioned and pseudoconditioned rats, but the heart rate response did not. Therefore, only the arterial pressure and freezing responses reflect the formation of an association between the tone and shock. Destruction of intrinsic neurons in the subcortical field contralateral to a unilateral MG lesion disrupted the associative conditioning of the arterial pressure and freezing responses. These were reduced in magnitude to the level observed in pseudoconditioned rats. The non-associative heart rate change was not affected by the lesions. That ibotenic acid destroyed intrinsic neurons and spared fibers in the subcortical field was demonstrated anatomically and biochemically. Thus, intrinsic neurons in the subcortical field innervated by the MG appear to mediate associative emotional conditioning. To determine whether the critical associative neurons are contained within the amygdala or caudate-putamen, additional animals were prepared with a unilateral MG lesion combined with injection of ibotenic acid contralaterally in either the posterior caudate-putamen or the amygdala. Caudate-putamen injections had no effect on any of the responses. In contrast, amygdala injections either disrupted both arterial pressure and freezing responses, disrupted only freezing, or had no effect on either. Amygdala injections did not reduce the heart rate changes. Those cell lesions of the amygdala which had no effect were significantly smaller than the lesions which disrupted one or both responses. The area of cell loss in the subgroup in which both responses were disrupted consistently involved the fundus striati (the putamen part of the amygdala) and the underlying central nucleus of the amygdala. The lesions disrupting only freezing responses were centered in the lateral nucleus and the lateral part of the central nucleus of the amygdala. The ineffective lesions were not …