Seizure-Induced Regulations of Amyloid-β, STEP₆₁, and STEP₆₁ Substrates Involved in Hippocampal Synaptic Plasticity

Figure 1

A single ECS but not chronic ECS transiently increases membrane-associated STEP₆₁ expression in the hippocampus. (a) Hippocampal expression of STEP₆₁ during postnatal development. Immunoblot analysis and quantification of STEP₆₁ and β-actin from the crude membrane (P2) fractions of rat hippocampi were obtained at postnatal days (P) 3, 7, 10, 12, and 14 ( rats per time point) and 21, 28, and 42 ( rats per time point). Background-subtracted western blot band intensities of STEP₆₁ and β-actin were normalized to those of P10 group, which was taken as 100%. STEP₆₁ expression significantly increased from P10 to P12 by 3-fold (, -test) and to P42 by 5-fold (, -test). (b) Schematic workflow of an experiment from ECS induction in rats to biochemical fractionation of their hippocampi. (c) Schematic experimental design of a single ECS and chronic ECS (a single ECS per day for 7 consecutive days). (d-e) Immunoblot analysis of STEP₆₁ in the hippocampal crude membrane (P2) fraction following a single ECS ((d) rats per time point) and chronic ECS ((e) rats per time point). Time points shown represent the duration after the induction of a single ECS (d) or chronic ECS (e) prior to brain removal. The ratio of the STEP₆₁ band intensity over the β-actin band intensity was calculated per each time point and normalized to the ratio of “no seizure” (NS) sham group, which was taken as 100%. Data shown represent the mean band intensity ± SEM. (c) A single ECS transiently increases STEP₆₁ expression in the hippocampus (). (d) Chronic ECS does not significantly alter STEP₆₁ expression in the hippocampus.

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