Two recent studies have given a breakthrough, by making inroads to find out the reason between explosions and traumatic brain injury (TBI). TBI has affected US soldiers in excess of 300,000, in the ongoing battles in Afghanistan and Iraq. Majority of them are due to high intensity explosions and bombs, triggered by terrorists. The main reason TBI is lack of expertise in establishing its relationship to bomb explosions.
Kevin Kit Parker a Harvard University bioengineer is the pioneer in these studies. He moved from cardiac to brain research, due to his own desire. This was due to his stint as a U.S. Army infantry officer in Afghanistan for two assignments, in which he witnessed his colleagues being affected by the explosions. This spurred him to investigate and look to find a lead for tackling TBI.
In his lab at Harvard he designed a blast simulator for cells. Rat neurons grown in a culture dish were joined to a stretchable thin polymer sheet. Sustained and measured jerks were given to the neurons. The report published in PLoS ONE, established the similarity between intensity of explosions and the jerks applied on the neurons.
Microscopic examination of the neurons showed that the explosions resulted in inflammation, rupture and indications of damage, on the dendrites and spindle shaped axons. These are used for inter neuron communication. Successive biochemical tests established that mechanical force, caused integrins, a form of protein, to break up. Integrins form a network of communication channels of biochemical signals for communication between neurons. Parker’s team found one particular channel that was the cause of injury to the axons. They established that a drug Rho kinase reduces the effect of injury on the axons.
The facts from the experiment showed thought-provoking similarity in damage of white matter of the brain, of soldiers comparable to the axons disruption. Brain white matter consists of axons. Parker cautioned that it was too early and more study and experiments were required to establish a foolproof connection between the two.
Vasospasm is a harmful mechanism in TBI. Parker group’s latest paper presented at the Proceedings of the National Academy of Sciences correlated the integrin communication to Vasospasm. They concluded from tests that there is a contraction of muscle cells lining blood vessels, due to a genetic switch. This is due to the impact of the sudden mechanical force, which causes oxygen starvation in brain, due to blood supply being cut off.
Jack Tsao, from Bethesda Maryland, a neurologist cum scientist at the Uniformed Services University of the Health Sciences says that medical practitioners are baffled by the duplication in vitro. TBI patients from blasts, had no internal bleeding in the brain, but had vasospasm, similar to stroke related attacks. Earlier it was thought that vasospasm only occurred due to blow on the head due to blasts.
The findings from the two published papers established that integrins are probably responsible for TBI and lot of inroads can be made to treat TBI or reduce its damage by giving preventive medicines. Earlier research had only proven neurochemical effects at the injury point, like metabolic changes and ion imbalances in the cells. David Hoda, director and neuroscientist of the Brain Injury Research Center at UCLA was all praise for the two papers and said their findings can be applied to treat other type of brain injuries resulting from automotive accidents and shaken baby syndrome.