Elitmus Exam Verbal Ability Miscellaneous

Oligodendrocytes are a group of highly specialised glial cells in the
central nervous system. They are responsible for the formation of
the fatrich
myelin sheath that surrounds the nerve fibres as an
insulating layer. The comparison with the coating on electricity
cables is an obvious one; however, myelin can do much more than
act as the insulating layer on electricity cables: it increases the
transmission speed of the axons and also reduces ongoing energy
consumption. The extreme importance of myelin for a functioning
nervous system is shown by the diseases that arise from a defective
insulating layer, such as multiple sclerosis
Interestingly, the function of the oligodendrocytes goes far beyond
the mere provision of myelin. KlausArmin
Nave and his team at the
Max Planck Institute in Göttingen already succeeded in
demonstrating years ago that healthy glial cells are also essential for
the longterm
function and survival of the axons themselves,
irrespective of myelination. “The way in which the oligodendrocytes
functionally support their associated axons was not clear to us up to
now,” says Nave. In a new study, the researchers were able to show
that the glial cells are involved in, among other things, the
replenishment of energy in the nerve fibres. “They could be
described as the petrol stations on the data highway of the axons,”
says Nave, explaining the results.
But how does the energy refuelling work? Is there a metabolic
connection between the oligodendrocytes and axons? To find out,
Ursula Fünfschilling generated genetically modified mice: the
function of the mitochondria was deliberately disrupted in the
oligodendrocytes through the inactivation of the Cox10 gene. This
affects the final stages of sugar breakdown taking place in the
mitochondria where energy is harnessed – a process known as the
respiratory chain. If a link in this chain is missing, in this instance
cytochrome oxidase, which is only functional when cells have the
enzyme Cox10, the glial cells gradually lose the capacity for cell
respiration in their mitochondria. “Without independent breathing,
the manipulated glial cells of the nervous systems should have died,”
explains the scientist. That is, unless the low level of energy
harnessed from the splitting of the glucose to form pyruvate or milk
acid, a process known as glycolysis, is sufficient for them

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Elitmus Other Question

How many three digits no. can be formed also including the condition that the no. can have at least two same digits ? X P B
*P M B
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P B E W
P W Q E
D P W D
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Q E B M D W
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