Daily Archives: February 2, 2012

How nerve cells reach their niche.

Developmental biology, the study of the processes through which organisms grow and develop, is an area of biomedical research where modal organisms – ranging from the slime mold Dictyostelium  discoideum to the chicken – play a crucial role, and one that has been honoured with several  Nobel Prizes in recent years.  For example, the 1995 prize for “discoveries concerning the genetic control of early embryonic development” was awarded for studies of the fruit fly  Drosophila melanogaster , and the  2002 prize for “discoveries concerning ‘genetic regulation of organ development and programmed cell death”, was awarded for research undertaken with the nematode worm Caenorhabditis elegans, while the 2007 prize for  “discoveries of “principles for introducing specific gene modifications in mice by the use of embryonic stem cells”” depended on studies of stem cells in the developing mouse embryo undertaken by Martin Evans.

Today on the Neurophilosophy blog Mo Costandi has another great example of how our knowledge of developmental biology is being advanced through animal research. In a post entitled “Astrocytes build blood vessel scaffolds for long distance neuron migrations” he discusses how a research team led by Dr Armen Saghatelyan  used  Green Fluorescent Protein labeling and genetic modification to track the processes that control the migration of nerve cells to their correct location in the developing mouse brain.

It’s fascinating work, and you can read about it on the Neurophilosophy blog here.

 

 

So what does this basic research in developmental biology mean to medicine?

Scientists have known for some time that the brain has a limited ability to repair itself following injury, for example after a stroke, and more recent studies have identified a critical role for adult neuronal precursor cells in this recovery.  But the process by these adult neuronal precursor cells migrate to the site of injury and integrate into the damaged brain circuitry is very inefficient, with only a small number of cells reaching the correct location, so scientists are working on a variety of approaches to boost the brain’s ability to repair itself.

One approach to doing this is the use of exogenous stem cells, such as the human embryonic stem cell derived neuronal precursor cells developed by the UK-based company ReNeuron that entered clinical trials for stroke in 2011.

Another avenue being pursued by several research groups around the world is to improve the efficiency with which the endogenous neuronal precursor cells migrate to and repair damaged regions of the brain. In order to develop therapies that improve endogenous brain repair scientists first need to understand the processes that drive – and limit – neuronal precursor production, migration and integration in the developing and adult brain, so that they can modify and enhance those processes to safely  optimize repair.  The work of Dr Saghatelyan and his colleagues has provided medical science with another important piece of a puzzle that when solved will benefit many thousands of stroke victims around the world.

Paul Browne