Following damage to the central nervous system (CNS), immune cells in the brain, known as microglia, are activated. Microglia are critical for protecting neural function and they have an important role in clearing debris and modulating the inflammatory response. However, following CNS injury, microglia can become dysregulated and play a key role in neurodegeneration.
Chahin et al., (2025) recently published in Communications Biology, present an animal model of single and repetitive concussions, which was able to reliably induce cognitive and learning impairments in the absence of deficits in motor function, a key confound in the assessment of cognition. The model did not induce macroscopic brain injury and did not induce hemorrhage, edema, contusion, bruising, skull fracture or cell death. As a result, the model was able to mimic human concussions, where cognitive impairments are typically seen in the absence of abnormalities on neuroimaging scans.
Following repetitive concussions, mice showed transient impairments in short-term and spatial memory which recovered 3-weeks post-injury. Authors found that repetitive concussions led to the temporarily microglia-mediated engulfment pre-synaptic excitatory inputs in the cortex and hippopcampus for several weeks after injury. These findings have important implications for our understanding of the neurobiology of concussions.
Authors found that repetitive concussions led to the temporary microglia-mediated engulfment of pre-synaptic excitatory inputs. Since the synchrony of pre- and post-synaptic excitatory signalling is critical for learning and memory, the temporary engulfment of excitatory pre-synaptic terminals in the cortex and hippocampus is likely to contribute to cognitive impairments following a concussion. These findings have important implications for our understanding of cognitive deficits following a concussion.
Dr McCorry considers that multiple concussions in clinical practice remain a challenging area to understand. At the recent international brain injury conference in Montreal, there were consistent findings of functional differences in imaging modalities in professional athletes who experience multiple concussions compared to those who don’t. Further research is needed to understand how these changes impact the risk of dementia, psychiatric conditions and chronic traumatic encephalopathy.
Contact us
0121 485 6000
contact@gyrusgroup.com
Gibraltar Head Office
5th Floor World Trade Centre
Bayside Road Gibraltar GX11 1AA
Te: +350 540 73608
Blog follow link: