Glial cells play an active role in the nervous system
Researchers study the speed and precision of signal transduction in the
brain

Date:
September 8, 2020
Source:
University of Mu"nster
Summary:
Researchers have discovered that glial cells - one of the main
components of the brain -not only control the speed of nerve
conduction, but also influence the precision of signal transduction
in the brain.



FULL STORY ==========================================================================
For the brain to work efficiently, it is important that a nerve impulse
arrives at its destination as quickly and as precisely as possible. It
has been long been known that the nerve fibres -- also known as axons --
pass on these impulses. In the course of evolution, an insulating sheath
-- myelin - - developed around the axons which increases the speed of conduction. This insulating sheath is formed by the second type of cell
in the nervous system - - the glial cells, which are one of the main
components of the brain. If, as a result of disease, myelin is depleted,
this leads to neurological disorders such as Multiple Sclerosis or
Morbus Charcot-Marie-Tooth.


========================================================================== Researchers at the University of Mu"nster have discovered that glial
cells not only control the speed of nerve conduction, but also influence
the precision of signal transduction. In the absence of these insulating sheaths, short-circuit- like processes occur, which influence the accuracy
of the stimulus transmission. The research results have been published
in the journal Nature Communications.

Background and methodology Glial cells are not only indispensable for
providing energy -- they also have a broad range of other tasks in the
brain. They are responsible for transport of metabolite and xenobiotics, regulating fluid exchanges, and maintaining ion homeostasis. In order to
better understand the importance of glial cells for neuronal signaling,
a team of researchers headed by Prof. Christian Kla"mbt at the Institute
of Neuro- and Behavioural Biology at the University of Mu"nster studied
changes in behaviour after the induced activation of individual neurons
in fruit flies (Drosophila melanogaster). "For this purpose," says
Christian Kla"mbt, "we either removed individual glial cells from the
nervous system or specifically disturbed their development concomitant
to a light-induced, optogenetic, neuronal activation." As a result
of these activities, the researchers were first able to ascertain
that glial cells control the radial growth of the axons. Smaller axons
have, as expected, a slower conduction speed -- which was determined by electrophysiological measurements in a collaboration with colleagues at
the University of Bonn. Astonishingly, it became apparent that a slower conduction speed does not lead to any change in movement behaviour. The
more important contribution made here by glial cells is the formation of membrane processes between individual axons -- which prevents electrical coupling (i.e. short circuits) and thus makes a decisive contribution
to the precision of neuronal signaling. The researchers undertook a
detailed analysis of larval locomotion by means of a special custom made device. The development of the so-called FIM (Frustrated total internal reflection-based Imaging Method), together with self-developed software,
allows a high-resolution depiction and analysis of movements made by even minute organisms. This led to a spin-off being set up - - the "qubeto"
company -- which now continues the development of this technology and
makes it available to the scientific community.

The function of glial cells as active modulators of the speed and, in particular, the precision of stimulus conduction, has not previously
been described. "What our research makes clear is the role played by
glial cells as active components in the nervous system," says Christian Kla"mbt, summing up the research results. "With these new findings we
are creating a basis for a better understanding of some of the symptoms
of diseases of the nervous system."

========================================================================== Story Source: Materials provided by University_of_Mu"nster. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Kottmeier, R., Bittern, J., Schoofs, A. et al. Wrapping glia
regulates
neuronal signaling speed and precision in the peripheral
nervous system of Drosophila. Nat Commun, 2020 DOI:
10.1038/s41467-020-18291-1 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/09/200908122511.htm

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