Sandi C, Rose S P
Brain and Behaviour Research Group, Open University, Milton Keynes, UK.
Eur J Neurosci. 1994 Aug 1;6(8):1292-7. doi: 10.1111/j.1460-9568.1994.tb00319.x.
Glucocorticoids can modulate behavioural processes and neural plasticity. They are released during learning situations and can trigger neural actions through binding to brain receptors. We hypothesized that a glucocorticoid action could play a critical role in the mechanisms involved in long-term memory formation. In order to test this hypothesis, chicks were trained on a passive avoidance learning task and given bilateral intracerebral injections of selective mineralocorticoid (RU-28318) or glucocorticoid (RU-38486) receptor antagonists. The results showed that both antagonists alter information processing when injected prior to the training session. Possible state-dependent effects were discharged. Further experiments evaluating possible effects of the antagonists on concomitant aspects of the learning situation (such as novelty reaction and pecking pattern) indicated that, as opposed to the glucocorticoid receptor antagonist, the mineralocorticoid antagonist altered the birds' reactivity to non-specific aspects of the training task. These results suggest that the two types of intracellular corticosteroid receptors could be mediating different aspects of the information processing and storage involved in avoidance learning. In addition, this study points out that passive avoidance learning in the chick could be a good model to investigate the biochemical mechanisms involved in corticosteroid actions on learning-induced neural plasticity.
糖皮质激素可调节行为过程和神经可塑性。它们在学习过程中释放，并可通过与脑受体结合触发神经活动。我们假设糖皮质激素作用可能在长期记忆形成所涉及的机制中起关键作用。为了验证这一假设，对小鸡进行被动回避学习任务训练，并对其双侧脑内注射选择性盐皮质激素（RU-28318）或糖皮质激素（RU-38486）受体拮抗剂。结果显示，在训练前注射时，两种拮抗剂均会改变信息处理过程。可能的状态依赖性效应被排除。进一步评估拮抗剂对学习情境伴随方面（如新奇反应和啄食模式）可能影响的实验表明，与糖皮质激素受体拮抗剂不同，盐皮质激素拮抗剂改变了鸟类对训练任务非特异性方面的反应性。这些结果表明，两种类型的细胞内皮质类固醇受体可能介导回避学习中信息处理和存储的不同方面。此外，本研究指出，小鸡的被动回避学习可能是研究皮质类固醇对学习诱导神经可塑性作用的生化机制的良好模型。
