Postnatal development of septal projections to the midbrain central gray in female rats: Tract-tracing analysis with DiI
Postnatal development of septal projections to the midbrain central gray in female rats: Tract-tracing analysis with DiI
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DOI：
10.1016/j.neulet.2006.09.085
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发表时间：
2007-01
影响因子：
2.5
通讯作者：
T. Kouki;K. Yamanouchi
中科院分区：
文献类型：
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作者：
T. Kouki;K. Yamanouchi
侧隔（LS）向中脑中央灰质（MCG）吻端的神经投射具有性别二态性，在抑制雌性生殖行为中起重要作用。在本实验中，用DiI示踪法检查了雌性大鼠从出生到出生后15天的LS-MCG连接的发育。在出生当天（D1大鼠）和出生后5、10或15天（分别为D5、D10或D15大鼠）或出生后8周（成年），通过灌注4%PFA和0.1%戊二醛的混合物固定脑。将DiI粘贴在LS的冠状切面上，并将样品在40°C下在PFA中孵育长达4个月。孵育后，制备200 μm冷冻的精子旁切片，并通过荧光显微镜观察。结果发现，成年大鼠视前区、下丘脑前部和后部以及MCG中存在大量DiI标记纤维。在D1大鼠，几个标记的轴突延伸到尾侧的下丘脑前区。在D5大鼠，少数标记纤维到达MCG。D10大鼠嘴侧MCG内可见标记纤维。在D15大鼠中，观察到相当数量的标记纤维到达MCG的嘴侧，并且纤维的相对密度与成人相当。这些结果表明，从LS到嘴侧MCG的神经通路在出生后5-10天到15天以上的时间内迅速发育。
The neural projection of the lateral septum (LS) to the rostral mesencephalic central gray (MCG) is sexually dimorphic and plays an important role in inhibiting female reproductive behavior. In this experiment, development of the LS–MCG connection from birth to 15 days after birth was examined in female rats by a tract-tracing method with DiI. On the birth day (D1 rat), and 5, 10 or 15 days after birth (D5, D10 or D15 rat, respectively) or 8 weeks after birth (adult), the brain was fixed by perfusion of a mixture of 4% PFA and 0.1% glutaraldehyde. DiI was pasted on the coronally cut-surface of the LS and the sample was incubated in PFA at 40°C for up to 4 months. After incubation, 200-μm frozen parasagital sections were prepared and observed by fluorescence microscopy. As a result, numerous DiI labeled fibers were found in the preoptic area, the anterior and posterior hypothalamus, and the MCG in adult rats. In D1 rats, several labeled axons extended caudal to the anterior hypothalamic area. In D5 rats, a few labeled fibers reached the MCG. Some labeled fibers were observed in the rostral MCG of D10 rats. In D15 rats, a considerable number of labeled fibers were seen to reach the rostral MCG and relative density of the fibers was comparable to that of adult. These results suggest that the neural pathway from the LS to the rostral MCG develops acutely during the period from 5–10 days up to more than 15 days after birth.