Allen G V, Cechetto D F
Robarts Research Institute, Department of Stroke and Aging, London, Ontario, Canada.
J Comp Neurol. 1992 Jan 15;315(3):313-32. doi: 10.1002/cne.903150307.
The present study describes the anatomical organization of projections from functionally defined cell groups of the lateral hypothalamic area. Cardiovascular pressor and depressor sites were identified following microinjection (5-50 nl) of 0.01-1.0 M L-glutamate or D,L-homocysteate into the anesthetized rat. Subsequent injections of Phaseolus vulgaris-leucoagglutinin (PHA-L) or wheat germ agglutinin-horseradish peroxidase (WGA-HRP) were made into pressor or depressor sites and their connections with the brainstem and spinal cord were traced. Decreases in blood pressure (10-45 mmHg) and heart rate (20-70 bpm) were elicited from tuberal (LHAt) and posterior (LHAp) regions of the lateral hypothalamic area (LHA). Depressor neurons in the LHAt have descending projections to the central gray, dorsal and median raphe nuclei, pedunculopontine tegmental nucleus, pontine reticular formation, medial and lateral parabrachial nuclei, laterodorsal tegmental region, and medullary reticular formation including the region of the lateral tegmental field, nucleus ambigous, and rostrocaudal ventral lateral medulla. In contrast, descending projections from depressor neurons in the LHAp have dense terminal fields in the rostral, middle, and commissural portions of the nucleus of the solitary tract and the lateral tegmental field as well as the ventrolateral central gray, pedunculopontine tegmental nucleus, and medial and lateral parabrachial nuclei. Both the LHAt and LHAp have light projections to the intermediate region of the cervical and thoracic spinal cord. Increases in blood pressure (10-40 mmHg) and heart rate (20-70 bpm) were elicited almost exclusively from neurons located medial to the LHAt and LHAp in a region surrounding the fornix, termed the perifornical area (PFA). Pressor cells in the PFA have descending projections to the central gray, dorsal and median raphe nuclei, laterodorsal tegmental nucleus, and Barrington's nucleus as well as a light projection to the commissural portion of the nucleus of the solitary tract and the intermediate region of the cervical and thoracic spinal cord. The retrograde labeling observed in the WGA-HRP studies indicates that cells in most terminal fields have reciprocal projections to the pressor and depressor regions of the LHA. The results demonstrate that groups of neurons in the lateral hypothalamus with specific cardiovascular function have differential projections to the brain stem.
本研究描述了下丘脑外侧区功能定义细胞群的投射的解剖组织。在对麻醉大鼠微量注射（5 - 50 nl）0.01 - 1.0 M L - 谷氨酸或D，L - 高半胱氨酸后，确定了心血管升压和降压位点。随后将菜豆白细胞凝集素（PHA - L）或小麦胚凝集素 - 辣根过氧化物酶（WGA - HRP）注射到升压或降压位点，并追踪它们与脑干和脊髓的连接。下丘脑外侧区（LHA）结节部（LHAt）和后部（LHAp）可引起血压下降（10 - 45 mmHg）和心率下降（20 - 70次/分钟）。LHAt中的降压神经元有下行投射至中央灰质、背侧和中缝核、脚桥被盖核、脑桥网状结构、内侧和外侧臂旁核、外侧背侧被盖区以及延髓网状结构，包括外侧被盖区、疑核和延髓腹外侧头尾部区域。相比之下，LHAp中降压神经元的下行投射在孤束核的头端、中间和连合部以及外侧被盖区以及腹外侧中央灰质、脚桥被盖核以及内侧和外侧臂旁核有密集的终末场。LHAt和LHAp都有少量投射至颈髓和胸髓的中间区域。血压升高（10 - 40 mmHg）和心率升高（20 - 70次/分钟）几乎完全由位于LHAt和LHAp内侧、围绕穹窿的一个区域（称为穹窿周区，PFA）中的神经元引起。PFA中的升压细胞有下行投射至中央灰质、背侧和中缝核、外侧背侧被盖核以及巴林顿核，还有少量投射至孤束核的连合部以及颈髓和胸髓的中间区域。在WGA - HRP研究中观察到的逆行标记表明，大多数终末场中的细胞与LHA的升压和降压区域有相互投射。结果表明，下丘脑外侧区具有特定心血管功能的神经元群对脑干有不同的投射。
