Pain Lecture - Blake Flashcards
what type of nerve fibers are used for nociception ?
C-fibers and A(delta) fibers
what type of receptors are found in the periphery and are important in signal transduction for nociception?
TRPV1 receptors
Define Hyperalgesia
heightened sense of pain to a noxious stimuli
define allodynia
pain resulting from normally painless stimuli
what is the predominant location of excitatory neuropeptide input from primary afferents?
What Lamina?
Substantia Gelatinosa
Lamina 2
what the are key spots in the brain that are involved in pain sensitization?
Periaqueductal grey (PAG) in the midbrain
thalamus
the sensory cortex and limbic system in the cerebrum
What is the PAG?
target in the midbrain for spinomesencephalic neurons. it is very important in the regulation of nociception.
what is the key structure in relaying descending pain modulations to the rostral ventromedial medulla nuclei (RVM)?
PAG
what sensory input is sent to the thalamus?
all but olfactory sensory systems
What is the Gate Control Theory?
Activation of Aβ fibers (large diameter afferents) inhibit the processing of signals from the Aδ and C-fibers
what is an example of the Gate Control theory?
Rubbing or massaging injured parted to achieve pain relief
What are the Neurotransmitters from primary afferents?
Glutamate
Aspartate
AMPA
NMDA
Glutamate and Aspartate are (blank) amino acids that act on ligand-activated ion channels.
Excitatory
AMPA is responsible for (blank) nociceptive transmission
fast
NMDA is responsible for (blank) depolarization
sustained
What are the excitatory neurotransmitters related to the 2nd messenger system?
CGRP (calcitonin gene-related peptide)
Substance P
What does CGRP do?
its effect is related to peripheral vasodilation, and augments nociception
What does Substance P do?
is co-released with glutamate, and modifies gain.
it is also released from peripheral axons and produces local tissue effects
What are the neurotransmitters from spinal interneurons?
GABA
Glycine
Opioids
acetylcholine
are the neurotransmitters released from the interneurons excitatory or inhibitory?
inhibitory
what are the 2 types of GABA receptors?
GABAA- fast-> produces hyperpolarization
GABAB- slow
What are the neurotransmitters from supraspinal sites?
Serotinin -5HT3 specifically
norepinephrine - a1 and a2 receptors
