Related Experiment Videos
Differences in striatal extracellular amino acid concentrations between Wistar and Fischer 344 rats after middle
R C Herz1, P J Gaillard, D J de Wildt
1Department of Medical Pharmacology, Rudolf Magnus Institute for Neurosciences, Utrecht University, The Netherlands.
Abstract:
We hypothesized that the interstrain difference between Wistar and Fischer-344 (F344) rats in cerebral infarction volume after proximal middle cerebral artery (MCA) occlusion might be explained by differences in excitotoxicity between both rat strains. Using microdialysis we measured during a 5 h period after MCA occlusion the release of aspartate, glutamate and taurine in the cerebral cortex and the striatum. The volume of striatal infarction was comparable in Wistar and F344 rats. We found, however, in Wistar rats a significantly higher striatal efflux of aspartate and glutamate than in F344 rats, whereas the striatal taurine efflux was of a similar magnitude in the two strains. Because of the (variably) smaller volume of cortical infarction in Wistar rats (than that in F344), the location of the microdialysis probe-membrane with respect to the area of cortical infarction differed between Wistar rats. Hence, a reliable comparison between the quantitative amount of amino acids in the dialysate from the cortical probes of both rat strains could not be made. These results, demonstrating differences in striatal excitotoxicity between Wistar and F344 rats after MCA occlusion, are the first to show interstrain differences in striatal pathophysiology of focal ischemia between these normotensive rat strains. They do however not explain why MCA occlusion results in a significantly different volume of cortical infarction between Wistar and F344 rats. The F344 strain will probably show in a more sensitive way, as compared to Wistar rats, neuroprotective effects of agents that diminish excitotoxic damage during focal cerebral ischemia.
Insights
Wistar rats show higher striatal excitotoxicity after middle cerebral artery (MCA) occlusion than Fischer-344 rats, but this difference does not explain varying cerebral infarction volumes between strains.
Area of Science:
- Neuroscience
- Pathophysiology
- Ischemic Stroke Research
Background:
- Interstrain differences exist in cerebral infarction volume following middle cerebral artery (MCA) occlusion between Wistar and Fischer-344 (F344) rats.
- Excitotoxicity is a potential mechanism underlying these observed differences in stroke volume.
Purpose of the Study:
- To investigate interstrain differences in excitotoxicity between Wistar and F344 rats following MCA occlusion.
- To determine if differences in amino acid release correlate with cerebral infarction volume.
Main Methods:
- Middle cerebral artery (MCA) occlusion was performed in Wistar and F344 rats.
- Microdialysis was used to measure aspartate, glutamate, and taurine release in the cerebral cortex and striatum for 5 hours post-occlusion.
- Striatal and cortical infarction volumes were assessed.
Main Results:
- Striatal infarction volumes were comparable between Wistar and F344 rats.
- Wistar rats exhibited significantly higher striatal efflux of aspartate and glutamate compared to F344 rats.
- Cortical amino acid measurements were unreliable due to variable infarction locations, preventing direct comparison.
Conclusions:
- Significant differences in striatal excitotoxicity exist between Wistar and F344 rats after MCA occlusion, highlighting interstrain variations in focal ischemia pathophysiology.
- The observed differences in striatal excitotoxicity do not fully explain the differing cortical infarction volumes between the rat strains.
- Fischer-344 rats may be more sensitive than Wistar rats in detecting neuroprotective effects against excitotoxic damage in focal cerebral ischemia.