The disturbance of hippocampal calcium-dependent responses in rats with PTSD-like behavior
Abstract：Aim To investigating hippocampal calcium and calcium-dependent responses in rats with posttraumtic stress disorder(PTSD)-like behavior and to further understand the neurobiological mechanisms involved in the long-term neuropsychological sequelae in PTSD.Methods 240 male Wistar rats were divided randomly into 3 groups.Group SE (n=96) for rats with PTSD-like behavior by constant pulsating current of 100 μ A with intratrain frequencies of 16 Hz, pulsating duration of 1 ms,train duration of 10 s and interstimulus interval of 7 min for 5 days with 8 times per day.Group CE (n=96) for control of electrode implanted in hippocampus without stimulation, and Group NC (n=48) for normal control.Neurochemistry,flow cytometer,fluorescence labeling technique and Western blotting were adopted to detect activities of Na+-K+-ATPase and Ca2+-ATPase, levels of intracellular calcium and free calmodulin (CaM),and the total CaM expression.Results The Na+-K+-ATPase activity in mitochondria of hippocampal cells in Group SE rats was significantly decreased at 12 h [( 0.56± 0.17) mmol/kg@ s,F=4.438,P< 0.05],and still lower than group NC at 48 h after the last stimulation [( 0.61± 0.17) mmol/kg@ s, P=0.026],while the Ca2+-ATPase activity was also significantly decreased at 48 h [(0.53± 0.14) mmol/kg@ s, F=4.999, P< 0.05] and 72 h post-stimulation [(0.61± 0.17) mmol/kg@ s, P=0.027 vs group NC].The intracellular free calcium levels were markedly increased than control groups from 12 to 48 hours (F=16.355,P< 0.01),and still elevated at 72 hour after the final stimulation [(290 ± 70) nmol/L,P=0.03 vs group NC].Meanwhile,the mean channel fluorescence of intracellular free CaM decreased remarkably synchronously (F=10.655,P< 0.05), while the Western analysis demonstrated the total hippocampal CaM expression was significantly elevated at 48 hour after the last stimulation in group SE rats (F=16.247,P< 0.05).Conclusion The lasting increased levels of intracellular free calcium and expression of Ca2+ /CaM in hippocampus, as well as the dysfunction of Na+-K+ pump and Ca2+-ATPase in hippocampal mitochondria may play important roles in the long-term neuropsychological sequelae in PTSD.
Keywords：stress disorderpost-traumaticadenosinetriphosphatasecalmodulinCa2+-transporting ATPasehippocampus
Publication Date：2003-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：3( 2672-2674 )