Somatosensory System and Pain
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Transcript of Somatosensory System and Pain
Somatosensory System and Pain
Prof. Marshall Devor, Ph.D.Dept. of Cell & Animal Biology and Center for research on Pain Institute of Life SciencesHebrew University of Jerusalem
lecture 6: Ascending pathways
פיסיולוגיה מורחבפיסיולוגיה מורחב 08-908-9
primary sensory neurons
perception vs.perception vs.regulationregulation
Spinal white matterpathways
antero-lateralcolumn
dorsal column
dorsal column – medial lemniscussystem
hand
foot
AA LTM LTMafferentsafferents
dorsal column nuclei
thalamus (ventro-basal nucleus)VPL, VPM
somatosensorycortex (S1)
dorsal column –medial lemniscussystem
light touch and vibration sense
anterolateral column system(spino-bulbo-thalamic system)
all types of all types of afferentsafferents
hand
foot
thalamus (ventro-basal nucleus)VPL, VPM
somatosensorycortex (S1)
spino-bulbo-thalamic system
which sense ?
brainstemnuclei"bulbo-"
spino-bulbo-thalamic system
dorsal column – medial lemniscus systemlight touch and vibration
spino-bulbo-thalamicsystemwhich sense ??
tabes dorsalis
anterolateral column system(spino-bulbo-thalamic system)
all types of all types of afferentsafferents
hand
foot
dorsal column – medial lemniscus systemlight touch and vibration
spino-bulbo-thalamicsystemall somato-visceral senses
primary sensory neurons
““medial pain pathway”medial pain pathway”lamina I (nociceptive) parabrachial n. (pons)amygdala + hypothalamus
succinyl dehydrogenase
barrel field (van der Loos)
homunculus
functional magneticresonance imaging fMRI
saggital human brain
anterior cingulate gyrus
CCoghill et al. 2003
constant stimulus, variable sensory response among subjects
propriospinal system
propriospinaltract
Somatosensory System and Pain
Prof. Marshall Devor, Ph.D.Dept. of Cell & Animal Biology and Center for research on Pain Institute of Life SciencesHebrew University of Jerusalem
lecture 6: Ascending pathways
פיסיולוגיה מורחבפיסיולוגיה מורחב
primary sensory neurons
• heterogeneity of primary afferents (heterogeneity of primary afferents (labeled line theory)labeled line theory)• divergence + convergence divergence + convergence different heterogeneity of second different heterogeneity of second
order projection neuronsorder projection neurons (2x specific, WDR, multireceptive)(2x specific, WDR, multireceptive)
• dynamic (RF size & response properties, central sensitization )dynamic (RF size & response properties, central sensitization )• multiple ascending pathwaysmultiple ascending pathways• multiple terminal areasmultiple terminal areas• descending control (feedback, feedforward, anticipation)descending control (feedback, feedforward, anticipation)
AQ
P
AQ
P
for every unique stimulus, a unique constellation of neural population activity
"Population activity theoryPopulation activity theory"
“bottom-up” vs. “top-down”