Hippocampal inactivation enhances taste learning.
Hippocampal inactivation enhances taste learning.
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DOI：
10.1101/lm.32305
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发表时间：
2005-11
影响因子：
2
通讯作者：
M. Stone;Brandon S. Grimes;D. Katz
中科院分区：
文献类型：
--
作者：
M. Stone;Brandon S. Grimes;D. Katz
学习任务通常被认为是海马依赖性的（海马损伤受损）或海马独立性的（海马损伤无关）。在这里，我们表明，条件性味觉厌恶（CTA）学习不适合这些类别。老鼠被训练避免两种味觉刺激，一种是新的，一种是熟悉的。通过手术植入的颅内插管输注蝇蕈醇，在熟悉过程中，随后的CTA训练，或两者兼而有之，暂时灭活背海马。如前所述，熟悉过程中海马失活增强了熟悉对学习的影响（即，海马失活增强了CTA的潜在抑制）;然而，更新颖和令人惊讶的是，发现训练期间海马失活强烈增强了CTA学习本身。这些现象不是由我们的输注技术的特定方面引起的--在熟悉过程中向海马中输注蝇蕈醇不会引起CTA，向味觉皮层中输注蝇蕈醇会引起CTA的预期衰减，而海马失活会引起空间学习的预期衰减。因此，我们认为海马记忆过程干扰CTA的具体学习机制，更普遍的是，多个记忆系统不独立运作。
Learning tasks are typically thought to be either hippocampal-dependent (impaired by hippocampal lesions) or hippocampal-independent (indifferent to hippocampal lesions). Here, we show that conditioned taste aversion (CTA) learning fits into neither of these categories. Rats were trained to avoid two taste stimuli, one novel and one familiar. Muscimol infused through surgically implanted intracranial cannulae temporarily inactivated the dorsal hippocampus during familiarization, subsequent CTA training, or both. As shown previously, hippocampal inactivation during familiarization enhanced the effect of that familiarization on learning (i.e., hippocampal inactivation enhanced latent inhibition of CTA); more novel and surprising, however, was the finding that hippocampal inactivation during training sessions strongly enhanced CTA learning itself. These phenomena were not caused by specific aspects of our infusion technique--muscimol infusions into the hippocampus during familiarization sessions did not cause CTAs, muscimol infusions into gustatory cortex caused the expected attenuation of CTA, and hippocampal inactivation caused the expected attenuation of spatial learning. Thus, we suggest that hippocampal memory processes interfere with the specific learning mechanisms underlying CTA, and more generally that multiple memory systems do not operate independently.