Transcript Ascending pathways and S1 cortex

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