A lateral hypothalamic D1 dopaminergic mechanism in conditioned taste aversion
A lateral hypothalamic D1 dopaminergic mechanism in conditioned taste aversion
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DOI：
10.1016/0006-8993(96)00426-x
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发表时间：
1996-08-12
期刊：
影响因子：
2.9
通讯作者：
Nicolaidis, S
中科院分区：
文献类型：
--
作者：
Caulliez, R;Meile, MJ;Nicolaidis, S
本研究的目的是阐明位于LHA中的神经元在获得味觉（条件刺激=糖精）和内脏不适（非条件刺激=氯化锂）之间的关联中的作用，导致条件性味觉厌恶（CTA）的长期延迟学习。在82只雄性大鼠中，引导套管被定向双侧进入基底外侧LHA，在条件刺激后和非条件刺激前进行双侧显微注射。我们发现：（2）D1受体特异性阻断剂SCH 23390也能阻断CTA的学习，而D2受体特异性阻断剂舒必利则无此作用;（3）D_1和D_2受体的特异性阻断均不能阻止内脏应激引起的饮水量减少，表明人们确实经历过内心的痛苦（4）假味觉厌恶学习（即没有内脏痛苦）揭示了D1和D2受体阻断剂本身既不诱导对糖精的味觉偏好也不诱导对糖精的味觉厌恶，这表明CTA的受损获得不是由于叠加的味觉偏好，该味觉偏好可能是由LHA内D1受体阻断诱导的。它的结论是，在LHA的neurology是必要的收购过程中的长延迟学习，它使用的D1受体特异性机制。
The aim of this study was to elucidate the role of the neuropil located in the LHA in the acquisition of the association between a taste (conditioned stimulus = saccharin) and a visceral distress (unconditioned stimulus = lithium chloride) leading to long delayed learning of a conditioned taste aversion (CTA). In 82 male rats guide-cannulae were directed bilaterally into the basolateral LHA where bilateral microinjections were made after the conditioned stimulus and before the unconditioned stimulus. We found that: (1) tetrodotoxin, a non-specific blocker of neuronal activity disrupted the acquisition of the CTA; (2) SCH 23390, a specific D1 receptor blocker also disrupted learning of the CTA, while sulpiride, a D2 receptor blocker, did not; (3) neither the specific blockade of D1 nor of D2 receptors could prevent the visceral distress-induced decrease in water intake, showing that the visceral distress was actually experienced; and (4) the sham taste aversion learning (i.e. without visceral distress) revealed that neither the D1 nor the D2 receptors blockade induced by themselves either a taste preference or a taste aversion towards saccharin, indicating that the impaired acquisition of the CTA was not due to a superimposed taste preference that could have been induced by the intra-LHA D1 receptors blockade. It is concluded that the neuropil in the LHA is necessary in the process of the acquisition of long delayed learning and that it uses a D1 receptor specific mechanism.