Valentino R J, Chen S, Zhu Y, Aston-Jones G
Department of Psychiatry, Medical College of Pennsylvania, Philadelphia 19102-1192, USA.
Brain Res. 1996 Sep 2;732(1-2):1-15. doi: 10.1016/0006-8993(96)00482-9.
The present study was designed to determine whether Barrington's nucleus, which lies ventromedial to the locus coeruleus (LC) and projects to the sacral parasympathetic nucleus, is a source of afferent projections to the LC. Restricted injections of the anterograde tracer, biocytin, into Barrington's nucleus labeled varicose fibers that extended from the injection site into the LC. Consistent with this, injections of the retrograde tracers, wheatgerm agglutinin conjugated to horseradish peroxidase coupled to gold particles (WGA-Au-HRP) or fluorescein-conjugated latex beads, into the LC labeled numerous (approximately 10%) Barrington's neurons that were also retrogradely labeled by Fluoro-Gold (FG) injections in the spinal cord. Retrograde tracing from the LC combined with corticotropin-releasing hormone (CRH) immunohistochemistry revealed that at least one third of the retrogradely labeled neurons in Barrington's nucleus were CRH-immunoreactive (CRH-IR). Finally, in triple labeling studies, CRH-Barrington's neurons were consistently observed that were retrogradely labeled from both the and spinal cord. These findings implicate Barrington's nucleus as an LC afferent and a source of CRH-IR fibers in the LC. Additionally, the results suggest that some Barrington's neurons diverge to innervate both the spinal cord and the LC. This divergent innervation may serve to coregulate the sacral parasympathetic nervous system and brain noradrenergic system, thus providing a mechanism for coordinating pelvic visceral functions with forebrain activity.
本研究旨在确定位于蓝斑（LC）腹内侧并投射至骶副交感核的巴林顿核是否为LC传入投射的来源。将顺行示踪剂生物胞素限制性注射到巴林顿核中，标记出从注射部位延伸至LC的曲张纤维。与此一致的是，将逆行示踪剂辣根过氧化物酶结合金颗粒的小麦胚凝集素（WGA-Au-HRP）或荧光素结合乳胶珠注射到LC中，标记出许多（约10%）巴林顿神经元，这些神经元也被脊髓中注射的氟金（FG）逆行标记。从LC进行逆行追踪并结合促肾上腺皮质激素释放激素（CRH）免疫组织化学显示，巴林顿核中至少三分之一的逆行标记神经元是CRH免疫反应性（CRH-IR）的。最后，在三重标记研究中，持续观察到CRH-巴林顿神经元从脑桥臂旁核和脊髓均被逆行标记。这些发现表明巴林顿核是LC的传入神经来源以及LC中CRH-IR纤维的来源。此外，结果表明一些巴林顿神经元发出分支，同时支配脊髓和LC。这种发散性神经支配可能有助于共同调节骶副交感神经系统和脑去甲肾上腺素能系统，从而为协调盆腔内脏功能与前脑活动提供一种机制。
