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Differential Effect of Amyloid Beta1–40 on Short-term and Long-term Plasticity in Dentate Gyrus of a Rat Model of Alzheimer Disease

INTRODUCTION: Synaptic plasticity is inappropriately affected by neurodegenerative diseases, including Alzheimer Disease (AD). In this study, we examined the effect of intrahippocampal amyloid-beta (Aβ1-40) on dentate gyrus Long-term Potentiation (LTP) and presynaptic short-term plasticity in a rat...

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Detalles Bibliográficos
Autores principales: Fahanik-Babaei, Javad, Baluchnejadmojarad, Tourandokht, Roghani, Mehrdad
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Iranian Neuroscience Society 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7878034/
https://www.ncbi.nlm.nih.gov/pubmed/33613890
http://dx.doi.org/10.32598/bcn.9.10.190
Descripción
Sumario:INTRODUCTION: Synaptic plasticity is inappropriately affected by neurodegenerative diseases, including Alzheimer Disease (AD). In this study, we examined the effect of intrahippocampal amyloid-beta (Aβ1-40) on dentate gyrus Long-term Potentiation (LTP) and presynaptic short-term plasticity in a rat model of AD. METHODS: The experimental groups in this research included the control with no treatment, sham-operated receiving the vehicle (normal saline), and Aβ-lesioned groups. For modeling AD, aggregated Aβ1-40 (10 μg/2 μl on each side) was injected into the hippocampal CA1. Three weeks later, Population Spike (PS) amplitude and slope ratios were determined at different Inter-pulse Intervals (IPI) of 10, 20, 30, and 50 ms as a valid indicator of the short-term presynaptic facilitation and/or depression. In addition, PS amplitude and slope were taken as an index of long-term synaptic plasticity after application of High-frequency Stimulation (HFS) to induce LTP in the medial perforant-dentate gyrus pathway. RESULTS: No significant differences were noted amongst the experimental groups regarding fEPSP slope and paired-pulse indices as indicators of short-term plasticity. In contrast, fEPSP slope and PS amplitude significantly decreased following the application of HFS in Aβ-injected group. In addition, there was no significant difference between the control and sham-operated groups regarding the mentioned parameters. CONCLUSION: Findings of this study clearly demonstrated that microinjection of Aβ1-40 into the CA1 could impair LTP in dentate gyrus but could not modify short-term plasticity.