Noradrenergic and GABAB receptor activation differentially modulate inputs to the premotor nucleus RA in zebra finches
Noradrenergic and GABAB receptor activation differentially modulate inputs to the premotor nucleus RA in zebra finches
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DOI：
10.1152/jn.01212.2007
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发表时间：
2008-07-01
影响因子：
2.5
通讯作者：
Perkel, David J.
中科院分区：
文献类型：
--
作者：
Sizemore, Max;Perkel, David J.
神经调节剂可以迅速改变神经回路，改变行为。鸣禽为研究神经调节在改变行为基础回路中的作用提供了一个极好的系统，因为鸣禽的学习和鸣叫是由一组相互连接的离散核介导的。采用体外全细胞电压钳记录技术，研究了去甲肾上腺素能和GABA B受体激活对斑胸草雀运动前强健核突触输入的神经调节作用。在成人中，去甲肾上腺素强烈减少了来自前乳头外侧大细胞核（LMAN）的输入，但仅轻微减少了来自HVC核（专有名称）、来自其他RA神经元轴突侧枝的兴奋性输入以及来自gaba能中间神经元的输入。去甲肾上腺素的作用被α(2)肾上腺素受体激动剂uk14304模拟，并被α(2)拮抗剂育亨宾阻断。相反，GABA B受体激动剂巴氯芬强烈减少RA神经元的HVC、侧支和GABA能输入，而LMAN输入几乎没有减少。在进行鸣叫学习的幼鱼中，去甲肾上腺素减少了LMAN输入，仅引起HVC输入的少量减少，而极大地减少了侧枝和gaba能输入。巴氯芬对幼鸟和成年鸟的影响相似，降低HVC、侧枝和gaba能输入的效果明显高于LMAN输入。配对脉冲比的显著增加伴随着突触传递的减少，提示突触前位点。去甲肾上腺素减少LMAN输入可能对调解由不同社会环境引起的歌曲变化很重要，并且很好地在歌曲学习中发挥作用。
Neuromodulators can rapidly modify neural circuits, altering behavior. Songbirds provide an excellent system for studying the role of neuromodulation in modifying circuits that underlie behavior because song learning and production are mediated by a discrete set of interconnected nuclei. We examined the neuromodulatory effects of noradrenergic and GABA B receptor activation on synaptic inputs to the premotor robust nucleus of the arcopallium (RA) in zebra finches using whole cell voltage-clamp recording in vitro. In adults, norepinephrine strongly reduced input from the lateral magnocellular nucleus of the anterior nidopallium (LMAN) but only slightly reduced the input from nucleus HVC (proper name), the excitatory input from axon collaterals of other RA neurons, and input from GABAergic interneurons. The effect of norepinephrine was mimicked by the alpha(2) adrenoceptor agonist UK14,304 and blocked by the alpha(2) antagonist yohimbine. Conversely, the GABA B receptor agonist baclofen strongly decreased HVC, collateral, and GABAergic inputs to RA neurons while causing little reduction in the LMAN input. In juveniles undergoing song learning, norepinephrine reduced the LMAN input, caused only a small reduction in the HVC input, and greatly reduced the collateral and GABAergic inputs. Baclofen caused similar results in juvenile and adult birds, reducing HVC, collateral, and GABAergic inputs significantly more than the LMAN input. Significant increases in paired-pulse ratio accompanied all reductions in synaptic transmission, suggesting a presynaptic locus. The reduction in the LMAN input by norepinephrine may be important for mediating changes in song elicited by different social contexts and is well-placed to play a role in song learning.