Moderate traumatic brain injury causes acute dendritic and synaptic degeneration in the hippocampal dentate gyrus

Xiang Gao, Ping Deng, Zao C. Xu, Jinhui Chen

Research output: Contribution to journalArticle

92 Citations (Scopus)

Abstract

Hippocampal injury-associated learning and memory deficits are frequent hallmarks of brain trauma and are the most enduring and devastating consequences following traumatic brain injury (TBI). Several reports, including our recent paper, showed that TBI brought on by a moderate level of controlled cortical impact (CCI) induces immature newborn neuron death in the hippocampal dentate gyrus. In contrast, the majority of mature neurons are spared. Less research has been focused on these spared neurons, which may also be injured or compromised by TBI. Here we examined the dendrite morphologies, dendritic spines, and synaptic structures using a genetic approach in combination with immunohistochemistry and Golgi staining. We found that although most of the mature granular neurons were spared following TBI at a moderate level of impact, they exhibited dramatic dendritic beading and fragmentation, decreased number of dendritic branches, and a lower density of dendritic spines, particularly the mushroom-shaped mature spines. Further studies showed that the density of synapses in the molecular layer of the hippocampal dentate gyrus was significantly reduced. The electrophysiological activity of neurons was impaired as well. These results indicate that TBI not only induces cell death in immature granular neurons, it also causes significant dendritic and synaptic degeneration in pathohistology. TBI also impairs the function of the spared mature granular neurons in the hippocampal dentate gyrus. These observations point to a potential anatomic substrate to explain, in part, the development of posttraumatic memory deficits. They also indicate that dendritic damage in the hippocampal dentate gyrus may serve as a therapeutic target following TBI.

Original languageEnglish
Article numbere24566
JournalPLoS One
Volume6
Issue number9
DOIs
StatePublished - Sep 13 2011

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Parahippocampal Gyrus
Dentate Gyrus
Brain
Neurons
neurons
brain
Dendritic Spines
Memory Disorders
immatures
Data storage equipment
Traumatic Brain Injury
Agaricales
dendrites
Cell death
synapse
Dendrites
mushrooms
Synapses
immunohistochemistry
cell death

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Medicine(all)

Cite this

Moderate traumatic brain injury causes acute dendritic and synaptic degeneration in the hippocampal dentate gyrus. / Gao, Xiang; Deng, Ping; Xu, Zao C.; Chen, Jinhui.

In: PLoS One, Vol. 6, No. 9, e24566, 13.09.2011.

Research output: Contribution to journalArticle

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