The traditional understanding in neuroscience
is that tactile sensations from the skin are only assembled to form a complete
experience in the cerebral cortex, the most advanced part of the brain.
However, this is challenged by new research findings from Lund University in
Sweden that suggest both that other levels in the brain play a greater role
than previously thought, and that a larger proportion of the brain's different
structures are involved in the perception of touch.
"It was believed that a tactile sensation, such
as touching a simple object, only activated a very small part of the cerebral
cortex. However, our findings show that a much larger part is probably
activated. The assembly of sensations actually starts in the brainstem",
said neuroscience researcher Henrik Jörntell at Lund University.
According to his colleague Fredrik Bengtsson, who also
participated in the research, this is the first study to show how complex
tactile sensations from the skin are coded at the cellular level in the brain.
"Our findings have given us a new key to
understanding how the perception of touch in the skin is processed and
communicated to the brain", he said.
The Lund researchers have worked in collaboration with
researchers in Paris to study how individual nerve cells receive information
from the skin. They used a 'haptic interface'*, which created controlled
sensations of rolling and slipping movements and of contact initiating and
ceasing. Movements proved decisive for the perception of touch - something that
was not previously technically possible to study.
The findings of the Swedish-French research group have
been published in the distinguished journal Neuron. The work is based on animal
experiments and is first and foremost basic research, which aims to increase
knowledge of the function of the brain. However, there are also possible areas
of application.
"Normal hand and arm prostheses do not give any
feedback and therefore no sensation of being a 'real' hand or arm. However,
there are new, advanced prostheses with sensors that can supply information to
the amputated arm. Our research could contribute to the further development of
such sensors", said Henrik Jörntell.
The new findings could also have a bearing on
psychiatric illness and brain diseases such as stroke
and Parkinson's
disease. Detailed knowledge of how the brain and its various parts
process information and create a picture of a tactile experience is important
to understanding these conditions.
"If we know how a healthy brain operates, we can
compare it with the situation in different diseases. Then perhaps we can help
patients' brains to function more normally", said Henrik Jörntell.
http://www.cell.com/neuron/abstract/S0896-6273(14)00649-7
No comments:
Post a Comment