Water self-diffusion tensor changes in an avian genetic developmental model of epilepsy

Author： Li Nan Gong Zhao Saucier Deborah Kendall Edward Sarty Gordon

ISSN： 1352-8661

Source： Magnetic Resonance Materials in Biology, Physics and Medicine, Vol.16, Iss.3, 2003-11, pp. : 121-128

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

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 (η and ε), trace and fractional anisotropy (FA) were generated. The η, ε, 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 η, ε, and trace with the largest differences between the stimulated and unstimulated birds being seen for η in juvenile birds in the archistriatum (38.1×10⁻¹¹ m²/s versus 18.0×10⁻¹¹ m²/s) and the optic tectum (53.9×10⁻¹¹ m²/s versus 27.1×10⁻¹¹ m²/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.