Collier P A, Ashwell K W
School of Anatomy, University of NSW, Kensington, Australia.
Neurotoxicol Teratol. 1993 Nov-Dec;15(6):439-44. doi: 10.1016/0892-0362(93)90062-s.
The three-dimensional distribution of neuronal heterotopiae induced in rat brains by prenatal exposure to the cytotoxic drug, methylazoxymethanol acetate, has been examined by computer reconstruction techniques. Three types of heterotopiae may be identified in mature rat brains exposed between E11 and E16: Layer I heterotopiae, periventricular heterotopiae, and hippocampal heterotopiae. The distributions of Layer I heterotopiae and periventricular heterotopiae show clear temporospatial gradients; such that with subsequent age of exposure, Layer I heterotopiae are situated progressively more medially, dorsally, and rostrally, and periventricular heteotopiae are situated progressively more rostrally. Periventricular heterotopiae are most extensive following exposure to the agent on E14. For both of these heterotopiae there is a characteristic pattern of distribution for each gestational age of exposure to the agent. By contrast, hippocampal heterotopiae, consisting of misplaced pyramidal neurons in subfields CA1 and CA2 of Ammon's horn, did not show significant changes in distribution with different ages of exposure to the drug. The significance of these temporospatial gradients for mechanisms underlying the production of the heterotopiae is discussed.
利用计算机重建技术，研究了产前暴露于细胞毒性药物乙酸甲基偶氮甲醇所诱导的大鼠脑内神经元异位的三维分布情况。在胚胎第11天至第16天期间暴露的成熟大鼠脑中，可识别出三种类型的异位：I层异位、脑室周围异位和海马异位。I层异位和脑室周围异位的分布呈现出明显的时空梯度；即随着暴露年龄的增加，I层异位逐渐位于更内侧、背侧和头侧，而脑室周围异位则逐渐位于更头侧。在胚胎第14天暴露于该药物后，脑室周围异位最为广泛。对于这两种异位，在暴露于该药物的每个胎龄都有其特征性的分布模式。相比之下，海马异位由海马角CA1和CA2亚区中位置异常的锥体细胞组成，其分布在不同的药物暴露年龄下未显示出显著变化。文中讨论了这些时空梯度对于异位产生机制的意义。
