@entity2227 dehydrogenase in astrocytes of the XXXX dentate gyrus following lesion of the entorhinal cortex.

@entity35 @entity2227 @entity4588
Applying quantitative microscopic histochemistry, the activity of the mitochondrial @entity2227 dehydrogenase which is localized in astrocytes was determined in the molecular layer of the dentate gyrus of the @entity35 hippocampus. This hippocampal region contains the important terminations of the glutamatergic perforant path. For comparison, determinations of the mitochondrial @entity4588 dehydrogenase were performed, which is localized preferentially in terminals and dendrites. Two age groups of animals were examined: young adults (three months old) and aged subjects (24 months old). Both age groups were divided into controls, and animals killed three, 21 and 90 days following unilateral electrolytic lesion of the entorhinal cortex. The post-lesional shrinkage of the terminal field of the perforant path, ipsilateral to the lesion side, was determined and considered in the evaluation of enzymatic data. Statistic analysis revealed that ipsilateral to the lesion side there was a significant decrease of @entity2227 and @entity4588 dehydrogenase activities in the terminal field of the perforant path three, 21 and 90 days following lesion. It is reasonable to assume that the decrease of @entity4588 dehydrogenase activity (50-60%) was caused by the loss of mitochondria localized in degenerating terminals, whereas the decrease of @entity2227 dehydrogenase activity (20-30%) was related to the decrease of glutamatergic transmission following lesion. In the terminal field of the perforant path contralateral to the lesion side both significant increases and decreases of enzyme activities were measured following lesion. From these results it is concluded that the hippocampus contralateral to the lesion side cannot be considered as an appropriate intraindividual control. The comparison between young and aged animals showed no differences in the demonstration of @entity2227 dehydrogenase and only restricted differences in the activity level of @entity4588 dehydrogenase post-lesion. Therefore, it is reasonable to assume that the post-lesional reactivity of the enzymes studied was very similar in both age groups.
