Persistent Cortical Changes in V1 of Mice after TBI

Article: Injuries to primary visual cortex cause long-term dysfunction of neural circuits
Source: Polish Academy of Sciences (Poland)
Published: January 24, 2022

Chronic neuron loss in V1 3 months after TBI

The brain possesses a remarkable degree of plasticity to reorganize, adapt, and self-repair after injury. However, neurotrauma such as traumatic brain injury (TBI) to the occipital cortex can result in mechanical damage and a variety of neuronal abnormalities that lead to long-term visual impairment. Using  in vivo electrophysiological recordings of adult mice two weeks and three months ("long-term") after a single mild controlled cortical impact injury to the primary visual cortex (V1), researchers in Poland and at UC Irvine found that although V1 remained intact, there was a ~35% reduction in the number of neurons, specifically inhibitory neurons. Functional decline to neurons included dramatically reduced activity, impaired responses to visual stimuli, and weaker size selectivity and orientation tuning. For example less than half (49%) of the isolated neurons were sensitive to visual stimuli at 3 months after TBI, compared with 90% of neurons in V1 of the control group. The findings show that even a single, mild contusion to the visual cortex can lead to long-term impairment of visual function that persist months after the event, providing insight to the development of circuit-level therapies for people like former soldiers.

My rating of this study: ⭐

Frankowski JC, Foik AT, Tierno A, et al. "Traumatic brain injury to primary visual cortex produces long-lasting circuit dysfunction." Communications Biology.  4:1297. 17 November 2021. https://doi.org/10.1038/s42003-021-02808-5