Currently, there is no effective treatment which can restore function
in a stroke patient once the first hours following a stroke have
passed. But, in the
future, the stroke-injured brain could be reparable by replacing dead
cells with new, healthy neurons, using transplantation.
Lund University in Sweden have taken a step in that direction by showing
that some neurons transplanted into the brains of stroke-injured rats
were incorporated and responded correctly when the rat's muzzle and paws
‘Some neurons transplanted into the brains of stroke-injured rats were incorporated and responded correctly when the rat's muzzle and paws were touched.’
The study, published in the prestigious journal Brain
human skin cells. These cells were re-programmed to the stem cell stage
and then matured into the type of neurons normally found in the
A couple of years ago, the research team at the Stem Cell Center in
Lund had already proven that transplanting this type of cells to the
cerebral cortex enabled stroke-injured rats to move better. At the time,
however, it was unclear whether the host brain really formed
functioning connections with the transplanted nerve cells. Now the new
study has proven that this is indeed the case.
The research team used several advanced methods in the study -
electron microscopy, virus-based tracing techniques, registration of
activity in the transplanted cells and optogenetics. The results show
that various parts of the host brain form normal, functioning
connections with the transplanted neurons and that the latter change
their activity when the animal's muzzle and paws are touched.
"This is the first time anyone has been able to show such a result.
That some of the new nerve cells receive signals from the host brain in a
normal way indicates that they have been incorporated into the
stroke-injured rat's brain. In it, they have been able to replace some
of the dead nerve cells", says the professor at the Stem Cell Center,
Now, a stroke-injured laboratory animal is not the same as a stroke
patient. But professor and consultant physician Olle Lindvall, who is
also part of the research team, still sees the team's study as an
important first step. It constitutes what is known as proof of concept,
showing that it is possible to replace dead neurons with new, healthy
cells through transplantation after a stroke.
"This is basic research, and it is not possible to say when we will
be ready to start experiments on patients. But the objective is clear:
to develop a treatment method which can repair the stroke-injured brain.", says Zaal Kokaia.