Food restriction alters neuronal morphology in the hypothalamic ventromedial nucleus of male rats
Food restriction alters neuronal morphology in the hypothalamic ventromedial nucleus of male rats
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DOI：
10.1210/en.2007-0008
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发表时间：
2008-01-01
期刊：
影响因子：
4.8
通讯作者：
LaBelle, Denise R.
中科院分区：
文献类型：
--
作者：
Flanagan-Cato, Loretta M.;Fluharty, Steven J.;LaBelle, Denise R.
一些证据表明，下丘脑腹内侧核(VMH)参与了热量平衡的控制。例如，VMH神经元的活动取决于能量的可用性。我们验证了能量平衡可能与VMH神经元树突重塑有关的假说。我们比较了两组动物：一组随意获得食物，另一组经历了10天的食物限制。正如预期的那样，缺乏食物的那组人体重减轻，血糖、胰岛素和瘦素水平降低。高尔基体染色后可见VMH神经元，并测量树突长度。食物剥夺对VMH神经元有不同程度的影响。特别是，在腹外侧VMH，对于具有向外侧而不是向内侧延伸的长初级树突(LPD)的神经元，LPD缩短了31%。这些神经元在胞体大小不变的情况下，其他树突的数量减少了32%。相反，在背内侧VMH内，LPD内侧而不是外侧延伸的神经元，胞体面积减少了28%。然而，背内侧VMH的神经元并没有显示出树突的长度或数量的变化，与LPD的方向无关。因此，尽管在卡路里耗竭期间，VMH的背内侧和腹外侧部都发生了结构变化，但只有后者表现出重塑的树突。这些结果还提示LPD的走向可能是VMH神经元功能的一个重要标志。
Several lines of evidence have implicated the hypothalamic ventromedial nucleus (VMH) in the control of caloric homeostasis. For example, the activity of VMH neurons depends on energy availability. We tested the hypothesis that energy balance may involve the remodeling of the dendritic arbor of VMH neurons. We compared two groups of animals: one group had ad libitum access to food, and the other experienced 10-d restricted access to food. As expected, the food-deprived group lost body weight and had reduced levels of glucose, insulin, and leptin. VMH neurons were visualized after Golgi impregnation, and dendrite length was measured. Food deprivation had differential effects on VMH neurons. In particular, within the ventrolateral VMH, for neurons with long primary dendrites (LPDs) that extended in the lateral, but not medial, direction, the LPDs were 31% shorter. These same neurons exhibited a 32% reduction in the number of other dendrites without a change in soma size. In contrast, within the dorsomedial VMH, for neurons with medially, but not laterally, extended LPDs, the soma area was reduced by 28%. However, neurons in the dorsomedial VMH did not display a change in the length or number of dendrites, regardless of LPD direction. Thus, although structural changes during calorie depletion occur in both the dorsomedial and ventrolateral VMH, only the latter exhibits a remodeled dendritic arbor. These results also suggest that the direction of the LPD may be an important marker of neuronal function in the VMH.