Otake K, Reis D J, Ruggiero D A
Department of Neurology and Neuroscience, Cornell University Medical College, New York, New York 10021.
J Neurosci. 1994 Sep;14(9):5694-707. doi: 10.1523/JNEUROSCI.14-09-05694.1994.
The goal of this study was to establish a structural basis for thalamic and visceral integration. We sought to define neural networks that convey visceral or integrated environmental stimuli to the diffuse thalamocortical relay system and that link periodic changes in forebrain and visceral reflex function. Our experiments were designed to determine whether afferents to the midline-intralaminar thalamic nuclei (MIT) issue collaterals to the general viscerosensory division of the nucleus tractus solitarii (NTS). Experiments were performed on anesthetized male Sprague-Dawley rats. Two tracers, FluoroGold and rhodamine latex microbeads, were stereotaxically centered on the MIT and NTS, respectively, in each animal. Subsets of midline thalamic afferents were identified that issue collaterals to the solitary complex. In the cerebral cortex, dually labeled soma were detected in layer V of the insular and infralimbic areas. In the subcortical forebrain, the lateral septal nucleus, anterolateral area of the bed nuclei of stria terminalis, medial preoptic nucleus, medial and central amygdaloid nuclei, caudal lateral hypothalamic area, supramammillary nucleus, and parvicellular division of the paraventricular hypothalamic nucleus constitute other newly identified sources of collateral projection. In the midbrain and pons, collateral projection cells were observed in the periaqueductal gray, dorsal raphe nucleus, mesencephalic reticular formation, laterodorsal tegmental nucleus, lateral and medial parabrachial nuclei, and noradrenergic A5 area. In the lateral parabrachial nucleus, dually labeled neurons were detected in the dorsal-lateral division. In the medulla, collaterals are derived from cells in the rostral and caudal ventrolateral reticular formation and parapyramidal area. Dually labeled cells were also found in the cerebellar fastigial nucleus. Collaterals may coordinate changes in visceral reflex excitability and thalamocortical rhythms during phases of sleep-wake cycle and behavioral expression.
本研究的目的是建立丘脑与内脏整合的结构基础。我们试图确定神经网络，这些网络将内脏或整合的环境刺激传递到弥散性丘脑皮质中继系统，并连接前脑和内脏反射功能的周期性变化。我们的实验旨在确定丘脑中线-板内核（MIT）的传入纤维是否向孤束核（NTS）的一般内脏感觉区发出侧支。实验在麻醉的雄性Sprague-Dawley大鼠身上进行。在每只动物中，分别将两种示踪剂氟金和罗丹明乳胶微珠立体定位到MIT和NTS。确定了中线丘脑传入纤维的一些亚群，它们向孤束复合体发出侧支。在大脑皮层，在岛叶和边缘下区的V层检测到双标记的神经元胞体。在皮质下前脑，外侧隔核、终纹床核的前外侧区、内侧视前核、杏仁核内侧和中央核、下丘脑外侧尾区、乳头体上核以及下丘脑室旁核的小细胞部构成了其他新确定的侧支投射源。在中脑和脑桥，在导水管周围灰质、背侧中缝核、中脑网状结构、外侧背盖核、外侧和内侧臂旁核以及去甲肾上腺素能A5区观察到侧支投射细胞。在外侧臂旁核的背外侧部检测到双标记神经元。在延髓，侧支来自延髓头端和尾端腹外侧网状结构以及锥体旁区的细胞。在小脑顶核也发现了双标记细胞。侧支可能在睡眠-觉醒周期和行为表达阶段协调内脏反射兴奋性和丘脑皮质节律的变化。
