History of the Understanding of Nerve Function
Dec 13, 2017 10:25:10 GMT -8
Post by Lαrα on Dec 13, 2017 10:25:10 GMT -8
I have been reading up on the historical understanding of nerve function and how this understanding has developed over the centuries. What surprised me more than anything is how recent (relatively ) the understanding of nerve function is. So is it any wonder that progress in research is playing catch up to some degree?
For many centuries, it was believed that the nerves functioned via 'animal spirits', which accessed the brain and travelled through the veins to allow movement.
The ancient theory of ‘animal spirits’ (pneuma psychikon in Greek; spiritus animalis in Latin) was first proposed by Alexandrian physicians in the third century BCE. Animal spirits were thought to be weightless, invisible entities that flowed through the hollow nerves to mediate the functioning of the body.
The animal spirits theory was related to the notion of the four humours (blood, phlegm, and yellow and black bile), and was popularised by the Roman physician Galen (c. 129 -216) in the second century AD. Because of Galen, animal spirits dominated thinking about the nervous system for 1,500 years; they were exorcised very recently – it was only during the latter part of the 18th century that investigators began to decipher the electrochemical language of the nervous system Source
The animal spirits theory was related to the notion of the four humours (blood, phlegm, and yellow and black bile), and was popularised by the Roman physician Galen (c. 129 -216) in the second century AD. Because of Galen, animal spirits dominated thinking about the nervous system for 1,500 years; they were exorcised very recently – it was only during the latter part of the 18th century that investigators began to decipher the electrochemical language of the nervous system Source
I am so surprised to see that this theory was never challenged to the point of changing the general opinion on this.
But now we know better!
( Now we know that we can thank these guys for those awful Nerve Tests with the needles! )
HerIn the early 1950s, Alan Hodgkin and Andrew Huxley carried out a series of 5 experiments which would determine how the electrical impulse (or action potential) was generated. By poking newly-developed, very fine microelectrodes directly into the giant axon of the squid, Hodgkin and Huxley measured the changes in membrane voltage that occurred during the action potential.
They thus established precisely the mechanism of the action potential: it was generated by the movements of ions across the nerve cell membrane, in both directions. Like Loewi and Dale before them, Hodgkin and Huxley would share a Nobel prize for their work. Source
They thus established precisely the mechanism of the action potential: it was generated by the movements of ions across the nerve cell membrane, in both directions. Like Loewi and Dale before them, Hodgkin and Huxley would share a Nobel prize for their work. Source
