• Experimental neurology · Nov 2015

    GABAergic interneuronal loss and reduced inhibitory synaptic transmission in the hippocampal CA1 region after mild traumatic brain injury.

    • Camila P Almeida-Suhett, Eric M Prager, Volodymyr Pidoplichko, Taiza H Figueiredo, Ann M Marini, Zheng Li, Lee E Eiden, and Maria F M Braga.
    • Program in Neuroscience, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA; Center for Neuroscience & Regenerative Medicine, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA. Electronic address: camila.almeida.ctr@usuhs.edu.
    • Exp. Neurol. 2015 Nov 1; 273: 11-23.

    AbstractPatients that suffer mild traumatic brain injuries (mTBI) often develop cognitive impairments, including memory and learning deficits. The hippocampus shows a high susceptibility to mTBI-induced damage due to its anatomical localization and has been implicated in cognitive and neurological impairments after mTBI. However, it remains unknown whether mTBI cognitive impairments are a result of morphological and pathophysiological alterations occurring in the CA1 hippocampal region. We investigated whether mTBI induces morphological and pathophysiological alterations in the CA1 using the controlled cortical impact (CCI) model. Seven days after CCI, animals subjected to mTBI showed cognitive impairment in the passive avoidance test and deficits to long-term potentiation (LTP) of synaptic transmission. Deficiencies in inducing or maintaining LTP were likely due to an observed reduction in the activation of NMDA but not AMPA receptors. Significant reductions in the frequency and amplitude of spontaneous and miniature GABAA-receptor mediated inhibitory postsynaptic currents (IPSCs) were also observed 7 days after CCI. Design-based stereology revealed that although the total number of neurons was unaltered, the number of GABAergic interneurons is significantly reduced in the CA1 region 7 days after CCI. Additionally, the surface expression of α1, ß2/3, and γ2 subunits of the GABAA receptor were reduced, contributing to a reduced mIPSC frequency and amplitude, respectively. Together, these results suggest that mTBI causes a significant reduction in GABAergic inhibitory transmission and deficits to NMDA receptor mediated currents in the CA1, which may contribute to changes in hippocampal excitability and subsequent cognitive impairments after mTBI.Copyright © 2015. Published by Elsevier Inc.

      Pubmed     Full text   Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…