Bagnoli P, Barsellotti R, Pellegrini M, Alesci R
Brain Res. 1983 Nov;312(2):243-50. doi: 10.1016/0165-3806(83)90140-2.
The endogenous level of norepinephrine (NE) was measured in discrete brain areas of the pigeon during post-hatching development. The pontine tegmentum showed the highest NE content, which remained constant during the post-hatching period. On the contrary, the NE content in the Wulst and cerebellum gradually decreased from hatching to 6 days. After this period, the Wulst NE level did not change significantly. In fact, there was no significant difference between NE values at 6 days and those at 6 months of age. In contrast, the difference between the cerebellar NE level at 6 days and that at the adult stage was highly significant. The NE content in the Wulst could be related to noradrenergic afferents originating in the ipsilateral locus coeruleus and substantia grisea centralis, since an electrolytic lesion of the pontine tegmentum caused a 60% reduction in the NE level in the ipsilateral Wulst. In line with the hypothesis that NE plays an important role in cortical plasticity, effects of early monocular deprivation on the Wulst NE content were also observed. After monocular deprivation during the first 6 months of life, the NE level increased by 40% in the Wulst ipsilateral to the deprived eye in comparison to the other side, where the NE level was normal. Monocular deprivation performed in adult animals did not affect the NE content in the Wulst. These results indicate that noradrenergic systems in the Wulst are affected by early, but not late visual deprivation.
在雏鸽孵化后的发育过程中，对其离散脑区的去甲肾上腺素（NE）内源性水平进行了测量。脑桥被盖区的NE含量最高，在孵化后的时期内保持恒定。相反，嗅叶和小脑的NE含量从孵化到6日龄逐渐下降。在此之后，嗅叶的NE水平没有显著变化。事实上，6日龄时的NE值与6月龄时的NE值之间没有显著差异。相比之下，6日龄时小脑的NE水平与成年期小脑的NE水平之间的差异非常显著。嗅叶中的NE含量可能与起源于同侧蓝斑和中央灰质的去甲肾上腺素能传入神经有关，因为脑桥被盖区的电解损伤导致同侧嗅叶中的NE水平降低了60%。符合NE在皮质可塑性中起重要作用这一假设的是，还观察到早期单眼剥夺对嗅叶NE含量的影响。在出生后的前6个月进行单眼剥夺后，与对侧NE水平正常的一侧相比，被剥夺眼同侧嗅叶中的NE水平增加了40%。成年动物进行单眼剥夺不会影响嗅叶中的NE含量。这些结果表明，嗅叶中的去甲肾上腺素能系统受到早期而非晚期视觉剥夺的影响。
