New formation of nerve cells and blood vessels earlier than expected after stroke

As early as one or two days after a stroke, that is, far earlier than was previously thought, the formation of new nerve cells and blood vessels gets underway in the affected area. This is indicated by findings in a dissertation by Wei Juang at Umeå University in Sweden.

Stroke is most often caused by a blockage of one of the heart’s blood vessels, which results in disrupted blood flow, so-called ischemic stroke. Brain damage occurs directly and spreads for the first few critical days. After that, the brain damage starts to heal, a process that can take many months and even years. It is not known what lies behind the capacity of the brain to recover.

In her dissertation Wei Jiang found that new formation of blood vessels, angiogenesis, starts in the brain as early as 24-48 hours after a stroke, that is, far earlier that was previously thought. Moreover, she found new formation of nerve cells in the damaged area. The newly generated nerve cells could be seen after seven days and were still in evidence up to 60 days after the damaged occurred. This new formation of blood vessels and nerve cells can be critical to the healing of the brain and offers the potential for entirely new treatments.

In experiments, the DNA in cells of animal models was injected with marked antibodies in a damaged area. In this way new nerve cell and blood vessel growth was demonstrated after a stroke. What’s more, the generation of proteins and energy molecules (ATP) in the brain was measured, as was blood flow, with the aid of isotope technology and laser Doppler.

Ischemic stroke is the third most common cause of death and the most common cause of functional impairment in adults. Every year 30,000 Swedes are affected by stroke. The severity of an acute ischemic stroke depends primarily on how long and to what extent the flow of blood to the brain is disrupted.

Title of dissertation: Regeneration in the adult brain after focal cerebral ischemia exploration of neurogenesis and angiogenesis