Perineuronal net degradation in XXXX .

@entity17202 @entity410 @entity19 @entity5093 @entity2134 @entity302 @entity35 @entity393 @entity159
OBJECTIVE: We previously reported loss of perineuronal net (PN) immunohistochemical staining around parvalbumin-positive interneurons in the hippocampus of @entity35 after an episode of @entity159 ( @entity159 ). We hypothesized that the loss of the PN could alter @entity410 susceptibility and that matrix metalloproteinases (MMPs) were candidates for degradation of the PN following @entity159 . METHODS: The @entity2134 chemoconvulsant @entity302 model was used to characterize the degradation of the aggrecan component of the PN in the hippocampus following @entity159 . Chondroitinase ABC (ChABC) was used to degrade the PN in @entity19 . Onset, number, and duration of @entity5093 ( @entity17202 )-induced @entity410 were assessed. RESULTS: The loss of the PN in the hippocampus following @entity159 is at least partially related to degradation of the aggrecan PN component by MMP activity. Forty-eight hours after @entity159 , a neoepitope created by MMP cleavage of aggrecan was present and concentrated around parvalbumin-positive interneurons. The increase in aggrecan cleavage products was found at 48  h, 1  week, and 2  months after @entity159 , with different fragments predominating over time. We demonstrate ongoing aggrecan proteolysis and fragment accumulation in the hippocampus of adult control @entity35 , as well as in @entity159 -treated animals. Degradation of the PN alters the @entity410 response to @entity17202 . ChABC treatment caused an increase in @entity410 following @entity17202 administration, a delayed onset of Racine stage 4/5 @entity410 , and a decreased duration of Racine stage 4/5 @entity410 . SIGNIFICANCE: @entity159 increases MMP proteolysis of aggrecan, pointing to MMP activity as one mechanism of PN degradation post- @entity159 . There is accumulation of aggrecan fragments in adult @entity35 hippocampus of both control and @entity159 -exposed animals. @entity393 was associated with increased numbers of @entity410 ; it also, delayed and shortened the duration of Racine stage 4/5 @entity410 , suggesting a complex relationship between the PN and @entity410 susceptibility.
