NEWS ABOUT NERVES

Greymouth Evening Star, 13 April 1927, Page 8

NEWS ABOUT NERVES

MESSAGE OF A BURN.

When- you burn your finger a nerve message is sent instantly up a nerve in your arm to a little knot of-living nerve cells called u gangliom Instantly a message goes down, another nerve to the muscle of the arm’’. These miiscies contract and.pull the endangered finger back to safety and surcease’ of pain. -That.-is the . conventional text book .description- Ofi the > simple' reflex act which an accitl.ental burn' or' pinch starts off dfi the', machinery rdf your body. • T-hO' -description ignores, - however, a quite important matter. What' is this : “nerve message” which •:the text-books suppose to bring news of danger and to take back’ orders for escape?That' has been for years :one . of’ the mysteries of physiology. It has been assumed, on reasonably good evidence, that nerve messages are electric.- : An electric current applied- to a nerve will usually produce the same muscular or other effects which the normal stimulation .of the nerve -produces. For example, electric stimulation of the optic nerve makes you seem to see a flash of light. Tests have shown, however, that nerve conduction is not a mere passage of an electric ■' current; 'tlie nerv'd jis ;sqffiethirig more —or‘ ' wire/carrying a'pulse .of’electricity; like thewire of your/doofbell. For blle'fihiiig, the s'peei 'of messages ovfer tlfe riervies' milch less than the speed" of electric i cilrrents through ‘ wires; ;

! Two recent investigations 'have thrown light on this mystery. Dr W. O. Fenn, of' Rochester University, infirmed "the scientific world recently, he had measured the amounts of oxygen gas consumed by a nerve while wbrkirigiat' its: job.’ If has flong bpett. known’ that .muscles must have oxygen wheii they work. . The kame isfonnd to'be true foriherves. Nerves bfeathe -faster, too,, when they work, just', as muscle fibres do. The other invest-fgatio comes from -Professor A. V. Hill; of London. He. has measured: the very tiny / quantities of heat which a. nerve, generates and emits into ■ the surrounding: • tiss’ue when it works. Most -of ’ this! heat is emitted, curiously enough, after-the’ message haspassed;'-hot; while- it is passing. It; isr.asr though ctfre- neiwe -first'-'ditT 'its Jdb without;getting; overheated or ex"cijtbd :anfl-; then feli c iirto rt iswehtxiver ffil after the emergency had passed; :