17 -Estradiol Benzoate Decreases the AHP Amplitude in CA1 Pyramidal Neurons
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چکیده
Kumar, Ashok and Thomas C. Foster. 17 -Estradiol benzoate decreases the AHP amplitude in CA1 pyramidal neurons. J Neurophysiol 88: 621–626, 2002; 10.1152/jn.00065.2002. Disruption of Ca homeostasis is hypothesized to mediate several electrophysiological markers of brain aging. Recent evidence indicates that estradiol can rapidly alter Ca -dependent processes in neurons through nongenomic mechanisms. In the current study, electrophysiological effects of 17 -estradiol benzoate (EB) on the Ca -activated afterhyperpolarization (AHP) were investigated using intracellular sharp electrode recording in hippocampal slices from ovariectomized Fischer 344 female rats. The AHP amplitude was enhanced in aged (22–24 mo) compared with young (5–8 mo) rats and direct application of EB (100 pM) reduced the AHP in aged rats. The age-related difference was due, in part, to the increased AHP amplitude of aged animals, since an EB-mediated decrease in the AHP could be observed in young rats when the extracellular Ca was elevated to increase the AHP amplitude. In aged rats, bath application of EB occluded the ability of the L-channel blocker, nifedipine (10 M), to attenuate the AHP. The results support a role for EB in modifying hippocampal Ca -dependent processes in a manner diametrically opposite that observed during aging, possibly through L-channel inhibition.
منابع مشابه
17beta-estradiol benzoate decreases the AHP amplitude in CA1 pyramidal neurons.
Disruption of Ca(2+) homeostasis is hypothesized to mediate several electrophysiological markers of brain aging. Recent evidence indicates that estradiol can rapidly alter Ca(2+)-dependent processes in neurons through nongenomic mechanisms. In the current study, electrophysiological effects of 17beta-estradiol benzoate (EB) on the Ca(2+)-activated afterhyperpolarization (AHP) were investigated ...
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