Bubser M, Scruggs J L, Young C D, Deutch A Y
Departments of Psychiatry and Pharmacology and Center for Molecular Neuroscience, Vanderbilt University School of Medicine, Nashville, TN 37212, USA.
Eur J Neurosci. 2000 May;12(5):1591-8. doi: 10.1046/j.1460-9568.2000.00052.x.
The nucleus accumbens of the rat consists of several subregions that can be distinguished on the basis of histochemical markers. For example, the calcium-binding protein calbindin D28k is a useful marker of the core compartment of the nucleus accumbens. Calretinin, another calcium-binding protein, is found in a dense fibre plexus in the accumbal shell and septal pole regions. The source of the accumbal calretinin innervation is not known. We examined the distribution of calretinin in the nucleus accumbens and used tract-tracing and lesion methods to determine the source of this calretinin innervation. Intense calretinin immunoreactivity was present in the medial shell, but the density of calretinin axons diminished sharply in the ventrolateral shell. Regions of dense calretinin immunostaining and those areas with calbindin-like immunoreactive cell bodies were generally segregated in the nucleus accumbens, although some overlap in the transition region between the core and shell was seen. Small clusters of calretinin-immunoreactive fibres were seen in the core, where they were restricted to calbindin-negative patches. Injections of the anterograde tracer biotinylated dextran amine into the paraventricular thalamic nucleus labelled fibres in calretinin-rich regions of the accumbens. Conversely, injections of Fluoro-gold into the accumbal shell retrogradely labelled numerous cells in the paraventricular thalamic nucleus that were calretinin-immunoreactive. Electrolytic lesions of the paraventricular thalamic nucleus reduced calretinin levels in the shell by approximately 80%. These data indicate that the calretinin innervation of the nucleus accumbens is derived primarily from the thalamic paraventricular nucleus, and marks accumbal territories that are largely complementary to those defined by calbindin.
大鼠伏隔核由几个可根据组织化学标记区分的亚区域组成。例如，钙结合蛋白钙视网膜蛋白D28k是伏隔核核心区的一个有用标记。另一种钙结合蛋白钙网膜蛋白则存在于伏隔核壳部和隔极区域的密集纤维丛中。伏隔核中钙网膜蛋白神经支配的来源尚不清楚。我们研究了钙网膜蛋白在伏隔核中的分布，并使用示踪和损伤方法来确定这种钙网膜蛋白神经支配的来源。钙网膜蛋白免疫反应强烈存在于内侧壳部，但钙网膜蛋白轴突的密度在腹外侧壳部急剧降低。在伏隔核中，钙网膜蛋白免疫染色密集的区域和那些具有钙视网膜蛋白样免疫反应性细胞体的区域通常是分开的，尽管在核心和壳部之间的过渡区域有一些重叠。在核心区可见小簇钙网膜蛋白免疫反应性纤维，它们局限于钙视网膜蛋白阴性斑块中。将顺行示踪剂生物素化葡聚糖胺注入丘脑室旁核，标记了伏隔核中富含钙网膜蛋白区域的纤维。相反，将荧光金注入伏隔核壳部，逆行标记了丘脑室旁核中许多钙网膜蛋白免疫反应性细胞。丘脑室旁核的电解损伤使壳部的钙网膜蛋白水平降低了约80%。这些数据表明，伏隔核的钙网膜蛋白神经支配主要来自丘脑室旁核，并标记了与由钙视网膜蛋白定义的区域在很大程度上互补的伏隔核区域。
