Hippocampal T2 signal change during amygdala kindling epileptogenesis.
OBJECTIVE
The rat electrical amygdala kindling model is one of the most widely studied animal models of temporal lobe epilepsy (TLE); however, the processes underlying epileptogenesis in this model remain incompletely understood. Magnetic resonance imaging (MRI) is a powerful method to investigate epileptogenesis, allowing serial imaging of associated structural and functional changes in vivo. Here we report on the results of serial MRI acquisitions during epileptogenesis in this model.


METHODS
Serial T2-weighted MR images were acquired before, during, and after the induction of kindling, to investigate the development and progression of imaging abnormalities.


RESULTS
T2-weighted acquisitions demonstrated the development of regions of increased signal in the rostral ipsilateral regions of CA1 and dentate gyrus in kindled (five of seven) but not in control rats (p < 0.05). Quantification of the T2 signal demonstrated a significant increase in kindled animals when compared with controls, 2 weeks after kindling ceased, in the ipsilateral hippocampus and the hippocampal sub regions of CA1 and the dentate gyrus (p < 0.05). No significant difference was observed in hippocampal volumes between kindled or control animals at any of the times.


CONCLUSIONS
The results of this study validate a method for acquiring serial MRI during amygdala kindling and demonstrate the induction of T2 signal abnormalities in focal regions of the hippocampus. These regions may be important sites for the neurobiologic changes that contribute to epileptogenesis in this model.
Jupp
Bianca
B
The Department of Medicine, The University of Melbourne, Royal Melbourne Hospital, The University of Melbourne, Parkville, Victoria, Australia.
Williams
John P
JP
Tesiram
Yasvir A
YA
Vosmansky
Milosh
M
O'Brien
Terence J
TJ
D000679:Amygdala / Q000502:physiology*; D000818:Animals; D001931:Brain Mapping; D018891:Dentate Gyrus / Q000473:pathology; D004195:Disease Models, Animal; D004558:Electric Stimulation; D004827:Epilepsy / Q000473:pathology*; D004833:Epilepsy, Temporal Lobe / Q000473:pathology; D007839:Functional Laterality / Q000502:physiology; D006624:Hippocampus / Q000473:pathology*; D007696:Kindling, Neurologic / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D051381:Rats; D017208:Rats, Wistar