Li C, Chen P, Smith M S
Division of Neuroscience, Oregon Regional Primate Research Center, Beaverton 97006, USA.
Regul Pept. 1998 Sep 25;75-76:93-100. doi: 10.1016/s0167-0115(98)00057-3.
Lactation induces an increase in NPY activity in two neuronal populations in the hypothalamus: the arcuate nucleus (ARH) and the dorsomedial nucleus (DMH) area. To determine if NPY neurons from these areas project to the paraventricular nucleus of the hypothalamus (PVH), the retrograde tracer, fluorogold (FG), was injected into the PVH of lactating females. FG-labeled NPY cells (identified by in situ hybridization for NPY mRNA) were observed throughout the ARH; however, a greater number of double-labeled cells were found in the caudal portion than the rostral portion of the ARH. Thus, NPY neurons in the caudal portion of the ARH provide the major ARH NPY input into the PVH area. If these results are combined with our previous data showing that activation of NPY neurons in the ARH during lactation is confined to the caudal portion, it is very likely that the lactation-activated NPY neurons project to the PVH. FG-labeled NPY cells were also identified in the DMH area, providing the first evidence that the NPY neurons in the DMH area activated during lactation also project to the PVH. Taken together, the increase in NPY activity may be important in modulating some of the physiological alterations occurring during lactation, such as the increase in food intake, in part through modulating PVH neuronal activity.
哺乳会导致下丘脑两个神经元群体中神经肽Y（NPY）活性增加：弓状核（ARH）和背内侧核（DMH）区域。为了确定来自这些区域的NPY神经元是否投射到下丘脑室旁核（PVH），将逆行示踪剂荧光金（FG）注入哺乳期雌性动物的PVH。在整个ARH中都观察到了FG标记的NPY细胞（通过NPY mRNA原位杂交鉴定）；然而，在ARH的尾部比头部发现了更多的双标记细胞。因此，ARH尾部的NPY神经元是PVH区域主要的ARH NPY输入源。如果将这些结果与我们之前的数据相结合，即哺乳期ARH中NPY神经元的激活局限于尾部，那么哺乳期激活的NPY神经元很可能投射到PVH。在DMH区域也鉴定出了FG标记的NPY细胞，这首次证明了哺乳期激活的DMH区域的NPY神经元也投射到PVH。综上所述，NPY活性的增加可能在调节哺乳期发生的一些生理变化中起重要作用，例如食物摄入量的增加，部分是通过调节PVH神经元活性来实现的。
