Need help understanding Adaptation in the eyes and somatosensory systems works

[FrankP]

Ok so this is not my strong subject however I need to understand it in order to write this one part of a neuroscience paper. I have been doing a lot of reading online and I have very finite notes on the subject and want to understand it a little better so I don't butcher it. 

 

So Magnocells are responsible for the rapid adaptation of the eye. I don't understand why or how. My notes state that they are responsible for a large receptive field is this why they are rapidly adapting because of the size of the receptive field if they were constantly responding they would require too much room in the cortex to process the visual information? 

 

Additionally I am not quite sure the process biochemically of how the adaptation works. Is it inhibitory neurotransmitters that prevent the Magnocells from continuing to fire the entire duration of the stimulus or is it the fact that the neurotransmitters only transmit at a action potential and the continued stimulus is a graded potential that does not reach the required threshold to cause firing? 

Lastly, in the sematosensory system I understand that the Meissner and Pacinian corpuscles are the ones that adapt to continuous pressure. My question is identical to the visual one, why and how? I understand that touch is something we adapt to and I know that because my teacher stated that the example of you can not feel your socks on your feet while you sit perfectly still however if you move in the slightest you can feel them again. I can fully wrap my head around such an example but I need neuroscience terminology so that I can look it up and understand it better because I am trying to write very specifically how this process/ system works. 

 

I understand that Meissners detects movement across the skin and so when there is no movement across the skin (such as sock) there is no firing of those neurons. I do understand vaguely how pacinian corpuscles adapt because of the anatomy of the end organ. Since it is layered with viscous solution between those layers the pressure that compresses the end organ is then resisted by the pacinian corepuscle itself and begins to ignore the stimulus. Why do both of these organs do this? 

 

I know this might be complicated to explain I don't need to write a dissertation however i just need helpful hints, descriptions or whatever in order to help me figure out what to read. I have read the book for the class and I am not really getting any more clarification.

 

Edited December 4, 2017 by FrankP