Li Nan, Gong Zhao, Saucier Deborah, Kendall Edward J, Sarty Gordon E
Division of Biomedical Engineering and Department of Medical Imaging, University of Saskatchewan, 9 Campus Drive, Saskatoon, Saskatchewan S7N 5A5, Canada.
MAGMA. 2003 Nov;16(3):121-8. doi: 10.1007/s10334-003-0020-x. Epub 2003 Oct 1.
Diffusion tensor imaging (DTI) was used to investigate whether tissue anisotropy in the developing brain is modified by recurrent seizures in epileptic chickens. Twelve epileptic chickens were sorted equally into two experimental groups at 10 days old. Until the age of 180 days, one group was photically stimulated beginning at an age of 2 weeks and repeated every 2 days while the other group was not stimulated. The photic stimulation induced generalized tonic-clonic seizures, and the unstimulated group did not display seizures. Both treatment groups were imaged at three time points, 45 (juvenile), 90 (adolescent), and 180 (adult) days posthatching, and maps of major and minor elements of anisotropy (eta and epsilon), trace and fractional anisotropy (FA) were generated. The eta, epsilon, and trace values in the hyperstriatum, archistriatum, and optic tectum showed significant changes as a function of developmental time point. Differences and/or interactions due to seizures were seen in the archistriatum and optic tectum for eta, epsilon, and trace with the largest differences between the stimulated and unstimulated birds being seen for eta in juvenile birds in the archistriatum (38.1 x 10(-11) m(2)/s versus 18.0 x 10(-11) m(2)/s) and the optic tectum (53.9 x 10(-11) m(2)/s versus 27.1 x 10(-11) m(2)/s). With the DTI parameters being sensitive to microstructure in the brain, these results demonstrate that seizures produce measurable differences, over unstimulated chickens, in brain structure for juvenile chickens, but the differences disappear as the brain matures. In other words, while seizure activity appears to induce atypical biophysical change (relative to unseizing birds) in the brain at a young age, the change is apparently reversed as the brain matures.
弥散张量成像（DTI）用于研究癫痫鸡反复癫痫发作是否会改变发育中大脑的组织各向异性。12只癫痫鸡在10日龄时被平均分为两个实验组。直到180日龄，一组从2周龄开始每隔2天接受一次光刺激，而另一组不接受刺激。光刺激诱发全身性强直阵挛发作，未受刺激的组未出现癫痫发作。两个治疗组在孵化后45天（幼年）、90天（青少年）和180天（成年）这三个时间点进行成像，并生成各向异性的主、次元素（η和ε）、迹值和分数各向异性（FA）图谱。上纹状体、原纹状体和视顶盖中的η、ε和迹值随发育时间点呈现显著变化。在原纹状体和视顶盖中，癫痫发作导致的η、ε和迹值差异和/或相互作用显著，其中幼年鸡原纹状体中受刺激和未受刺激鸡之间η的差异最大（38.1×10⁻¹¹ m²/s对18.0×10⁻¹¹ m²/s），视顶盖中（53.9×10⁻¹¹ m²/s对27.1×10⁻¹¹ m²/s）。由于DTI参数对大脑微观结构敏感，这些结果表明，与未受刺激的鸡相比，癫痫发作会使幼年鸡的大脑结构产生可测量的差异，但随着大脑成熟，这些差异会消失。换句话说，虽然癫痫活动在幼年时似乎会在大脑中诱发非典型的生物物理变化（相对于未发作的鸡），但随着大脑成熟，这种变化显然会逆转。
