Quantitative hippocampal structural changes following electroconvulsive seizure treatment in a rat model of depression

Authors

  • Susanne S. Kaae,

    1. Stereology and EM Laboratory, Centre for Stochastic Geometry and Advanced Bioimaging, Aarhus University Hospital, DK-8000 Aarhus C, Denmark
    2. Centre for Psychiatric Research, Aarhus University Hospital, DK-8240 Risskov, Denmark
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  • Fenghua Chen,

    Corresponding author
    1. Stereology and EM Laboratory, Centre for Stochastic Geometry and Advanced Bioimaging, Aarhus University Hospital, DK-8000 Aarhus C, Denmark
    2. Centre for Psychiatric Research, Aarhus University Hospital, DK-8240 Risskov, Denmark
    • Stereology and Electron Microscopy Laboratory, Danish Neuroscience Centre, 3rd Floor, Building 10G, Aarhus Sygehus, Aarhus University Hospital, Noerrebrogade 44, DK-8000 Aarhus C, Denmark
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  • Gregers Wegener,

    1. Centre for Psychiatric Research, Aarhus University Hospital, DK-8240 Risskov, Denmark
    2. Unit for Drug Research and Development, School of Pharmacy (Pharmacology), North-West University, Potchefstroom, South Africa
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  • Torsten M. Madsen,

    1. H. Lundbeck A/S, International Clinical Research, Dept. 317, Ottiliavej 7-9, DK-2500 Valby, Denmark
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  • Jens R. Nyengaard

    1. Stereology and EM Laboratory, Centre for Stochastic Geometry and Advanced Bioimaging, Aarhus University Hospital, DK-8000 Aarhus C, Denmark
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Abstract

Objective: The pathophysiology of depression and the effects of antidepressant treatment are hypothesized to be related to hippocampal structural changes. This study aims to investigate the effect of electroconvulsive seizures on behavior and hippocampal structure in a rat model of depression. Methods: Flinders Sensitive Line (FSL) and Flinders Resistant Line (FRL) rats were treated daily for 10 days with either electroconvulsive seizures or sham treatment. The behavior was evaluated using the forced swim test. Design-based stereological methods were used to quantify the hippocampal volume and the numbers of neurons and glial cells in specific hippocampal subregions. Results: The basal level of hippocampal volume and neuron number differed significantly between the two rat strains, and a trend toward the FSL strain having more glial cells was found. The structural differences found between the sham-treated animals were counteracted by electroconvulsive seizure (ECS) treatment, which also normalized the behavior. ECS treatment increased the number of glial cells in hilus significantly in the FRL rats and with the same tendency for the FSL rats. Conclusion: Our results indicate that along with hippocampal neurogenesis, gliogenesis may also be involved in the pathophysiology of depression and in the effect of antidepressant treatment. The underlying mechanisms remain unknown, and further investigations are required to clarify whether the structural changes are necessary to induce a therapeutic effect of antidepressant treatment or if they rather represent an epiphenomenon. Synapse, 2012. © 2012 Wiley Periodicals, Inc.

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