Midterm 2 notes Flashcards
what are the two types of sensitization
peripheral
central
peripheral sensitization
neurochemical
central sensitization
occurs in the central nervous system
where does central sensitization happen
either the DRG or the spinal cord
skin-nerve preparation
take a piece of skin from animal (while its alive) and tease out a nerve fibre that would be running from the skin to the DRG and spinal cord and put it un a bath to keep it alize and record it
what are you looking for when completing skin-nerve preparation
at the number of action potentials per second that the nociceptor has fired
for skin-nerve preparation, with more bradykinin
more action potentials are firing at lower temperatures including non-noxious temperatures
Clifford Wolf
discovered central sensitization in sole-authored study published 1983
Clifford Woolf study
he applied heat stim to rats to measure the lowest amount of mechanical stim in grams it would take for the rat to try to withdraw from it
how did Clifford Woolf measure the things in his study
using the WDR (second-order) neurpns in the spinal cord
what happened to the rats after the injury CW
the rats were allodynic for ~5hrs. The neurons fire more and the fire lasts longer
what happened to the rats before the injury CW
they fire but its stops really quickly
what shocked ppl in the CW study
the neurons were firing on the contralateral side
what was the only way to explain the surprising part of CW study
if the WDR neurons themselbes had changed such that a stimulus would normally not be painful before the injury but after the injury, the WDR neurons changed their properties such that normal stim of intact, noninjured skin on the other side of the body is making them fire as well
electrophysiological recording can distinguish between
peripheral and central sensitization
how does electrophysiological recording distinguish between the two?
by either record in the periphery or in the spinal cord
