Modulation of olfactory learning in young rats through intrabulbar GABAB receptors
Modulation of olfactory learning in young rats through intrabulbar GABAB receptors
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DOI：
10.1046/j.1460-9568.2003.02894.x
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发表时间：
2003-10-01
影响因子：
3.4
通讯作者：
Kaba, H
中科院分区：
文献类型：
--
作者：
Okutani, F;Zhang, JJ;Kaba, H
在出生后第 11 天进行气味与足部电击配对的训练后，幼鼠在出生后第 12 天的测试中表现出对气味的厌恶。这种厌恶嗅觉学习的机制涉及通过体感刺激诱导源自蓝斑的离心去甲肾上腺素能纤维的激活，对嗅球中的二尖瓣/簇状细胞进行去抑制。二尖瓣/簇状细胞的活性通过外部丛状层中的γ-氨基丁酸(A) (GABA(A)) 受体和肾小球层中的GABA(B) 受体进行调节。我们之前已经提出，幼鼠的厌恶性嗅觉学习是通过嗅球中的 GABA(A) 受体调节的。在本研究中，我们检查了训练期间操纵嗅球中 GABA(B) 受体的结果。巴氯芬是一种 GABA(B) 受体激动剂，在气味与足部电击配对期间注入嗅球时，会以剂量依赖的方式阻止厌恶性嗅觉学习。在没有足部电击的情况下进行柠檬醛气味训练时，输注沙氯芬（一种 GABA（B）受体拮抗剂）不仅会产生对气味的厌恶反应，还会对以前未出现过的奇怪气味（苯甲醛和香草醛）产生厌恶反应。即使在没有气味暴露的情况下输注沙氯芬，也会观察到这种嗅觉厌恶。这些结果表明，幼鼠的嗅觉学习是通过嗅球中的 GABA(B) 受体调节的。
After training with an odour paired with foot shock on postnatal day 11, rat pups show an aversion to the odour in testing on postnatal day 12. The mechanisms underlying this aversive olfactory learning involve disinhibition of mitral/tufted cells in the olfactory bulb by the somatosensory stimulation-induced activation of centrifugal noradrenergic fibres originating in the locus coeruleus. The activity of mitral/tufted cells is regulated through gamma-aminobutyric acid(A) (GABA(A)) receptors in the external plexiform layer and GABA(B) receptors in the glomerular layer. We have previously presented that aversive olfactory learning in young rats is modulated through GABA(A) receptors in the olfactory bulb. In the present study we examined the consequence of manipulating GABA(B) receptors in the olfactory bulb during training. Baclofen, a GABA(B) receptor agonist when infused into the olfactory bulb during the pairing of an odour with foot shock, prevented aversive olfactory learning in a dose-dependent manner. Infusion of saclofen, a GABA(B) receptor antagonist, during training with a citral odour in the absence of foot shock produced aversive responses not only to the odour, but also to strange odours (benzaldehyde and vanillin) not previously presented. Such olfactory aversions were observed even if saclofen was infused without odour exposure. These results suggest that olfactory learning in young rats is modulated through GABA(B) receptors in the olfactory bulb.