Miki Takanori, Harris Simon J, Wilce Peter A, Takeuchi Yoshiki, Bedi Kuldip S
Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa Medical University, Kagawa, Japan.
Hippocampus. 2004;14(1):124-34. doi: 10.1002/hipo.10155.
We have previously shown that exposing rats to a relatively high dose of ethanol during early postnatal life can result in an alteration in spatial learning ability. The hippocampal formation is known to be involved in the control of this ability. The purpose of the present study was to determine whether exposure of rats to ethanol during early postnatal life had either immediate or delayed effects on the numbers of pyramidal cells in the CA1-CA3 subregion of the hippocampus. Wistar rats were exposed to a relatively high daily dose of ethanol at postnatal day 10-15 by placing them for 3 h/day in a chamber containing ethanol vapor. Groups of ethanol-treated (ET), separation control (SC), and mother-reared control (MRC) rats were anesthetized and killed at 16 and 30 days of age by perfusion with phosphate-buffered 2.5% glutaraldehyde. The Cavalieri principle was used to determine the volumes of the CA1 and CA2+CA3 regions. The physical disector method was used to estimate the numerical density of neurons in each of the subdivisions. The total number of pyramidal cells was calculated by multiplying the appropriate estimates of the numerical density by the volume. There were significant age-related reductions in the total numbers of pyramidal cells at 16-30 days of age irrespective of the groups examined. Ethanol treated rats were found to have slightly but significantly fewer pyramidal cell neurons than either the MRC or SC groups. These observations indicate that pyramidal cells in the hippocampus may be vulnerable to a relatively high dose of ethanol exposure during this short period of early postnatal life.
我们之前已经表明，在出生后早期将大鼠暴露于相对高剂量的乙醇中会导致空间学习能力发生改变。已知海马结构参与这种能力的控制。本研究的目的是确定在出生后早期将大鼠暴露于乙醇中是否对海马CA1-CA3亚区的锥体细胞数量有即时或延迟影响。通过将Wistar大鼠每天置于含有乙醇蒸气的腔室中3小时，在出生后第10-15天使其暴露于相对高剂量的乙醇中。在16天和30天时，通过用磷酸盐缓冲的2.5%戊二醛灌注，将乙醇处理组（ET）、分离对照组（SC）和母养对照组（MRC）的大鼠麻醉并处死。使用 Cavalieri 原理确定CA1和CA2+CA3区域的体积。使用物理分割器方法估计每个亚区中神经元的数值密度。通过将数值密度的适当估计值乘以体积来计算锥体细胞的总数。无论检查的是哪个组，在16-30天龄时，锥体细胞总数均有与年龄相关的显著减少。发现乙醇处理的大鼠的锥体细胞神经元比MRC组或SC组略少但显著减少。这些观察结果表明，在出生后早期的这段短时间内，海马中的锥体细胞可能易受相对高剂量乙醇暴露的影响。
