The human brain is probably the most complex material in the universe. In the functional brain scanner (fMRI) an instrument was found to study the brain painlessly while it functions. All over the world researchers have the opportunity to use it, and the yield grows richer and more impressive each day.

The things that go on under the cranium are not miraculous: the number of connections between the brain cells are about 10 to the power of fourteen. A (futile) attempt to make such a figure comprehensible: add together the whole population of the Earth, then multiply that number by 160 000, then you get an approximation of the number of connections that make you who you are, determine how you think, what you can remember. In this complex, vulnerable environment many things can happen that can lead to sickness and death. Hence the attention paid to brain research all over the world. Here are some recent interesting results from that research.

Restored memory

Everyone knows at least one person in his or her social environment, family members, friends or acquaintances who has Alzheimer’s disease, a neurodegenerative condition that is characterized by loss of neurones in specific areas of the brain (mainly in the temporal cortex, but also in the frontal cortex), and by the formation of amyloid plaques and nodes in the brain tissue, causing parts of the brain to die.

The number of Alzheimer patients is increasing as the population continues to grow older. Throughout the world the search continues for the underlying causes of this terrible disease, and for ways and means of curing it. Up to now we have not progressed beyond drugs and medicines that slow down the progress of the disease to some extent. Recently, however, an encouraging report came from America’s Columbia University: damage to the brain can be repaired, memory can be restored.

But let’s not celebrate too soon: this is a case of laboratory tests on transgenic mice with amyloid plaques in the brain and damaged synapses (contact points that enable communication between the brain cells). The researchers gave the mice a specific substance (the enzyme Uch-L1) and discovered that the mices’ memories had been restored.

The researchers warn against any unduly high hopes for the short term. A great deal of research must be conducted before we can envisage applications for human beings. However, there is a growing consensus that we are on the right track, and that the discovery probably opens the door to new medicines.

New nerve cells for the brain

New Zealand and Swedish researchers have discovered a new sort of cell in the human brain. They showed the existence of stem cells in certain areas of the brain that control perception of smell; they are situated just under the ventricles, which are brain chambers filled with liquid. It was already known that in mice and rats with tubes filled with brain fluid such cells help to migrate to the hearing-sensitive region, and they also help to develop into nerve cells. Until now this has not been observed in humans. The researchers have now discovered such tubes in human brains, housing stem cells and cells that are gradually transformed into nerve cells during their journey. According to experts this discovery could be important for future research on the recovery of patients with brain injuries or with neurodegenerative diseases such as Alzheimer. It has now been demonstrated that this research on mice and rats is also valuable for the study of human brains.

However, the importance of this research is the discovery of a group of brain cells in the adult human brain that can be continuously renewed. We have perhaps finally found the trail of the stem cells that, in certain circumstances, may cause brain tumours.

Brain tumours shrink

Brain cancer is one of the most deadly cancers. Recently a treatment was given in the U.S. with favourable outcome on patients with a brain tumour who had relapsed after treatment with conventional methods such as surgery, radiotherapy and chemotherapy.

A tumour needs oxygen to be able to grow. The oxygen is supplied through new blood vessels forming around the tumour. The new treatment had the objective of preventing formation of the new blood vessels. The expectation is that the tumours will naturally shrink once the blood supply is insufficient.

And that is what actually happened: after administration of a suitable medication (AZD2171) to 16 patients with brain tumours it was found that in three quarters of the cases the dimensions of the tumour had shrunk by 25%, and by a good half in half of the patients.

At the present moment it is still not known bow the process will progress. The research continues, and it is hoped that finally this approach will be of interest not only for patients with relapsing brain tumours, but also with for patients with newly detected brain tumours.

Hidden dangers

Brains are extremely complex organs, and that also makes them vulnerable and sensitive to the slightest disorders. A group of American and Danish researchers has warned that any number of chemical substances may have a negative influence on the functions of the brain. Their report mentioned 200 industrial chemicals, including metals, solvents and pesticides that can damage the brain. They suggest a causal relation between the spread of these substances and the observed fact that one in six children worldwide have an abnormality such as autism or a motor defect. One example is the effect of lead that was used in petrol between 1960 and 1980 and that probably reduced IQ and concentration capacity, impaired motor coordination and caused increased aggression. According to the researchers 202 industrial chemicals have already been identified as harmful to the human brain. But this is probably only the tip of the iceberg, since only less than half of the 100 000 chemical substances in circulation have been subjected to an elementary test for toxicity.

Europe recently made an important step to turn the tide. The EC “Reach” programme is designed to limit the use of hazardous chemicals. Whether these measures will be sufficient remains to be seen. In any case it is high time to use our brains, as long as we still can!

  |terug|mail|print|top|