Evidence for a regional specificity in the density and distribution of noradrenergic varicosities in rat cortex.
Evidence for a regional specificity in the density and distribution of noradrenergic varicosities in rat cortex.
复制标题
DOI：
10.1002/cne.23270
复制
发表时间：
2013-07-01
期刊：
影响因子：
--
通讯作者：
Waterhouse BD
中科院分区：
文献类型：
--
作者：
Agster KL;Mejias-Aponte CA;Clark BD;Waterhouse BD
脑干蓝斑核（LC）是哺乳动物皮质中含去甲肾上腺素（NE）纤维的唯一来源。以往的研究表明，大鼠皮质去甲肾上腺素能纤维的密度是比较均匀的，核团内的细胞放电是密集的。这意味着LC的激活导致NE在整个皮质中的等效释放。然而，这是可能的，可能有不同的轴突静脉曲张的密度在不同地区，这些差异，而不是纤维密度的差异可能有助于调节NE流出。采用无偏采样方法，对几个皮质区域和丘脑腹后内侧（VPM）的多巴胺β羟化酶（DβH）免疫染色静脉曲张进行定量。DβH静脉曲张的密度在前额叶皮质中大于运动皮质、躯体感觉皮质或梨状皮质，在皮质浅层中大于深层，在VPM中大于躯体感觉皮质。我们的研究结果提供了解剖学证据的非均匀释放NE跨功能离散的皮质区域。这种形态学可以解释LC输出对不同皮层区域的差异性、区域特异性影响。
The brainstem nucleus locus coeruleus (LC) is the sole source of norepinephrine (NE)-containing fibers in the mammalian cortex. Previous studies suggest that the density of noradrenergic fibers in rat is relatively uniform across cortical regions and that cells in the nucleus discharge en masse. This implies that activation of the LC results in equivalent release of NE throughout the cortex. However, it is possible that there could be differences in the density of axonal varicosities across regions, and that these differences, rather than a difference in fiber density may contribute to the regulation of NE efflux. Quantification of dopamine beta hydroxylase (DβH) immunostained varicosities was performed on several cortical regions and in the ventral posterior medial (VPM) thalamus using unbiased sampling methods. The density of DβH varicosites is greater in the prefrontal cortex than in motor, somatosensory, or piriform cortices, greater in superficial than in deep layers of cortex, and greater in VPM than in somatosensory cortex. Our results provide anatomical evidence for non-uniform release of NE across functionally discrete cortical regions. This morphology may account for differential, region specific, impact of LC output on different cortical areas.