RESUMO
The return of consciousness after traumatic brain injury (TBI) is associated with restoring complex cortical dynamics; however, it is unclear what interactions govern these complex dynamics. Here, we set out to uncover the mechanism underlying the return of consciousness by measuring local field potentials (LFP) using invasive electrophysiological recordings in patients recovering from TBI. We found that injury to the thalamus, and its efferent projections, on MRI were associated with repetitive and low complexity LFP signals from a highly structured phase space, resembling a low-dimensional ring attractor. But why do thalamic injuries in TBI patients result in a cortical attractor? We built a simplified thalamocortical model, which connotes that thalamic input facilitates the formation of cortical ensembles required for the return of cognitive function and the content of consciousness. These observations collectively support the view that thalamic input to the cortex enables rich cortical dynamics associated with consciousness.
Assuntos
Lesões Encefálicas Traumáticas/fisiopatologia , Eletrocorticografia , Tálamo/fisiopatologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Free radicals are downstream mediators of several cytotoxic cascades contributing to ischemic brain injury. Molecular hydrogen (H2) is an antioxidant potentially useful in the treatment of stroke. Hydrogen is easy to deliver, biologically non-toxic and diffuses freely through all biological structures including the blood-brain barrier and cellular membranes. This study evaluated the efficacy of hydrogen treatments in a rat stroke model compared to vehicle-treated controls using multiparametric MRI and neurological tests. Additionally, comparison of H2 treatment alone was made with H2 combined with minocycline (H2M) treatment (12 rats per group). The primary findings were: i) H2 therapy reduced infarct volume in both H2 and H2M groups compared to controls at 1 and 7 days after stroke, and ii) both H2 and H2M improved neurologic functional recovery on day 7. The secondary outcomes were: iii) H2M treatment attenuated post-stroke hyperperfusion in the hyperacute phase, and iv) H2M markedly minimized white matter injury. In conclusion, this is the first study to use MRI to longitudinally study H2 and H2M treatment on ischemic stroke and the first study to compare H2 treatment combined with another potential stroke therapeutic (H2M).