Biomedical Engineering Reference
In-Depth Information
7.3 Neuropharmacology
Nanotechnologies target the brain at the molecular scale. A particular appli-
cation of such new technologies is the investigation of the effect drugs have on
neurons with particular regard to regenerative purposes. Regenerative medicine
shows remarkable promise not only to treat symptoms but also to restore
neural functionality, both at the peripheral and at the central nervous system
level. An important aspect of this is the investigation of neuron regeneration
and neuron plasticity, with a special focus on neurogenesis, the production of
nerve cells from stem cells. The generation of neural stem cells happens deep
within the brain, where they subsequently migrate to become part of the
circuitry of the brain. Neuro-electronic devices have tremendous potential in
evaluating the best course of action for the use of stem cells in the re-population
or replacement of brain cells destroyed by injury or disease.
A number of experimental drugs are thought to be effective in the treatment
of neurodegenerative conditions but, for the most part, their mechanism of
action remains largely unknown. Furthermore, finding the correct drug and its
proper dosage often relies on trial and error. Therefore, these diseases can
continue a slow progression and are dicult to detect. In addition, specific drug
responsiveness depends strongly on the individual patient, thus requiring
considerable personalization, even if the molecule in question is considered
capable of crossing the brain-blood barrier. Treating the symptoms and
slowing down further degeneration is often all that can be achieved today for
such diseases.
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7.4 Genetics
As we entered the 21st century many thought that the greatest hope for the
practical outcome of the Human Genome Project was the eventual elimination
of genetic diseases, including those of the neural variety. The overriding
concept was that certain diseases could be stopped 'at the source'. After
spending many millions of dollars to decode the human genome, the Holy Grail
was not found: the contribution of the genes variants to disease is rather weak.
When it comes to genetics and the brain there have been attempts to relate
genes to the likes of criminality and anti-social behaviour, with the expected
limited success.
Human genetic engineering involving the addition or deletion of defect genes
in the genetic material provided by parents is largely resisted on ethical
grounds. Somatic gene therapy performed by manipulating the genome of an
individual in order to obviate deleterious effects of a single gene gave
unfounded hopes and generated extreme technical diculties even in the case of
very well researched genetic conditions such as the diseases of the brain or
central nervous system, Huntington's disease and multiple sclerosis. Beyond
that, the problems are compounded by the fact that all common diseases
involve not just a single gene but a concert of genetic mutations. Recent
microarray technologies can now identify thousands of gene variants and very
