Neuroscience 2005 Abstract
| Presentation Number: | 432.6 |
|---|---|
| Abstract Title: | Amygdala kindling results in increased hippocampal T<sub>2</sub> signal without change in apparent diffusion coefficient or volume during epileptogenesis in the rat. |
| Authors: |
Jupp, B. M.*1
; Williams, J.2
; O'Brien, T. J.1
1Medicine, Univ. of Melbourne, Parkville, Australia 2Australia, Royal Melbourne Hospital, 3050, |
| Primary Theme and Topics |
Disorders of the Nervous System - Epilepsy -- Human studies and animal models |
| Secondary Theme and Topics | Disorders of the Nervous System<br />- Epilepsy<br />-- Basic mechanisms |
| Session: |
432. Epilepsy: Rat Models I Poster |
| Presentation Time: | Monday, November 14, 2005 9:00 AM-10:00 AM |
| Location: | Washington Convention Center - Hall A-C, Board # RR2 |
| Keywords: | TLE, MRI, HIPPOCAMPUS, EPILEPSY |
Purpose: Patients with non-lesional temporal lobe epilepsy (NLTLE) commonly show prominent imaging abnormalities on magnetic resonance imaging (MRI) in the ipsilateral temporal lobe in the absence of hippocampal atrophy. The rat amygdala kindling model shows many of the characteristics of NLTLE, including a relative lack of cell loss in the hippocampus. It is unknown if the imaging changes seen in NLTLE also are present in this model. The present study aimed to determine whether imaging changes seen on MRI in NLTLE are also detectable in the hippocampus in the rat amygdala kindling model, and then utilise this model to investigate the processes underlying these changes.
Methods: MRI compatible were developed to enable imaging without the induction of ‘artefacts’. Surgeries were performed according to well-established methods. Following one week recovery, T2 and diffusion weighted images were acquired every two weeks for six weeks on a 4.7T MRI. Electrical stimulations began the day following the first imaging session and continued six days a week for four weeks. T2 signal intensity, apparent diffusion coefficient (ADC) and hippocampal volumes were quantified.
Results: MRI demonstrated the development of focal regions of hyper-intense T2 signal in the rostral hippocampus during kindling (n=5/7) ipsilaterally to the site of stimulation, specifically in CA1 and dentate gyrus (p>0.05). Hippocampal ADC and volume was unaltered when compared to control animals.
Conclusions: We have developed a method for acquiring high quality serial MRI images in amygdala kindled rats. These results demonstrate that amygdala kindling produces an increase in T2 weighted MRI similar to those seen in NLTLE independent of change in hippocampal volume or ADC. This model will provide a powerful tool to investigate the pathophysiological basis of the imaging changes and epileptogenesis in this common form of epilepsy.
Methods: MRI compatible were developed to enable imaging without the induction of ‘artefacts’. Surgeries were performed according to well-established methods. Following one week recovery, T2 and diffusion weighted images were acquired every two weeks for six weeks on a 4.7T MRI. Electrical stimulations began the day following the first imaging session and continued six days a week for four weeks. T2 signal intensity, apparent diffusion coefficient (ADC) and hippocampal volumes were quantified.
Results: MRI demonstrated the development of focal regions of hyper-intense T2 signal in the rostral hippocampus during kindling (n=5/7) ipsilaterally to the site of stimulation, specifically in CA1 and dentate gyrus (p>0.05). Hippocampal ADC and volume was unaltered when compared to control animals.
Conclusions: We have developed a method for acquiring high quality serial MRI images in amygdala kindled rats. These results demonstrate that amygdala kindling produces an increase in T2 weighted MRI similar to those seen in NLTLE independent of change in hippocampal volume or ADC. This model will provide a powerful tool to investigate the pathophysiological basis of the imaging changes and epileptogenesis in this common form of epilepsy.
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2005 Neuroscience Meeting Planner. Washington, DC: Society for Neuroscience, 2005. Online.
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