6 Somatosensitivity, viscerosensititvity, proprioception and pain II 1 Viscerosensitivity • An information from visceral and cardiovascular system • Linked to the autonomic nervous system • The most of information does not reach higher structures than hypothalamus • The most of information does not reach consciousness • Parasympathetic nervous system (IX., X.) – „ Operational information“ (blood pressure, pO2, pCO2) • Sympathetic nervous system – „Potential danger“ (pressure, pain, cold) 2 Proprioception • Information from muscles, tendons and joints • Important for precise coordination of movements • Overload protection • More will be discused in lecture about motor 3 Somatosensory pathways • Three systems • (Archispinothalamic) – Interconnection of adjacent segments (tr. Spinospinalis) • Paleospinothalamic – tr. Spinoreticularis, tr. Spinotectalis… • Neospinothalamic – tr. Spinothalamicus • Dorsal column system – tr. Spinobulbaris 4 Somatosensory pathways • Three systems • (Archispinothalamic) – Interconnection of adjacent segments (tr. Spinospinalis) • Paleospinothalamic – tr. Spinoreticularis, tr. Spinotectalis… • Neospinothalamic – tr. Spinothalamicus • Dorsal column system – tr. Spinobulbaris 5 Somatosensory pathways • Paleospinothalamic – Low resolution – dull, diffuse pain („slow pain“) • Neospinothalamic – High resolution – sharp, localized pain („fast pain“), temperature – Low resolution – touch • Dorsal column system – High resolution – touch, proprioception 6 Somatosensory pathways • Paleospinothalamic – Low resolution – dull, diffuse pain („slow pain“) • Neospinothalamic – High resolution – sharp, localized pain („fast pain“), temperature – Low resolution – touch • Dorsal column system – High resolution – touch, proprioception 7 Paleospinothalamic system • Tr. Spinoreticularis, spinotectalis… 8 Paleospinothalamic system • Tr. Spinoreticularis, spinotectalis… • Evolved before neocortex 9 Paleospinothalamic system • Tr. Spinoreticularis, spinotectalis… • Evolved before neocortex • The primary connection to the subcortical structures 10 Paleospinothalamic system • Tr. Spinoreticularis, spinotectalis… • Evolved before neocortex • The primary connection to the subcortical structures • Basic defensive reactions and reflexes - vegetative response, reflex locomotion - opto-acoustic reflexes etc. 11 Paleospinothalamic system • Tr. Spinoreticularis, spinotectalis… • Evolved before neocortex • The primary connection to the subcortical structures • Basic defensive reactions and reflexes - vegetative response, reflex locomotion - opto-acoustic reflexes etc. • Secondarily connected to cortex (after its evolution; tr. Spinoreticulo-thalamicus), but this system has a small resolutions – dull diffuse pain 12 Paleospinothalamic system • Tr. Spinoreticularis, spinotectalis… • Evolved before neocortex • The primary connection to the subcortical structures • Basic defensive reactions and reflexes - vegetative response, reflex locomotion - opto-acoustic reflexes etc. • Secondarily connected to cortex (after its evolution; tr. Spinoreticulo-thalamicus), but this system has a small resolutions – dull diffuse pain • This tract is not designed for „such a powerful processor as neocortex“ 13 Paleospinothalamic system • Tr. Spinoreticularis, spinotectalis… • Evolved before neocortex • The primary connection to the subcortical structures • Basic defensive reactions and reflexes - vegetative response, reflex locomotion - opto-acoustic reflexes etc. • Secondarily connected to cortex (after its evolution; tr. Spinoreticulo-thalamicus), but this system has a small resolutions – dull diffuse pain • This tract is not designed for „such a powerful processor as neocortex“ • Approximately half of the fibers cross the midline 14 http://neuroscience.uth.tmc.edu 15 Neospinothalamic system • Tr. Spinothalamicus 16 Neospinothalamic system • Tr. Spinothalamicus • Younger structure primarily connected to neocortex • „High capacity/resolution“ 17 Neospinothalamic system • Tr. Spinothalamicus • Younger structure primarily connected to neocortex • „High capacity/resolution“ • Detail information about pain stimuli (sharp, localized pain) • Information about temperature 18 Neospinothalamic system • Tr. Spinothalamicus • Younger structure primarily connected to neocortex • „High capacity/resolution“ • Detail information about pain stimuli (sharp, localized pain) • Information about temperature • Crude touch sensation 19 Neospinothalamic system • Tr. Spinothalamicus • Younger structure primarily connected to neocortex • „High capacity/resolution“ • Detail information about pain stimuli (sharp, localized pain) • Information about temperature • Crude touch sensation • The fibers cross midline at the level of entry segment 20 http://neuroscience.uth.tmc.edu 21 Dorsal column system • Tr. Spinobulbaris 22 Dorsal column system • Tr. Spinobulbaris • The youngest system • High capacity 23 Dorsal column system • Tr. Spinobulbaris • The youngest system • High capacity • Tactile sensation • Vibration • Proprioception 24 Dorsal column system • Tr. Spinobulbaris • The youngest system • High capacity • Tactile sensation • Vibration • Proprioception • Fine motor control • Better object recognition • Adaptive value 25 Dorsal column system • Tr. Spinobulbaris • The youngest system • High capacity • Tactile sensation • Vibration • Proprioception • Fine motor control • Better object recognition • Adaptive value • The fibers cross midline at the level of medulla oblongata 26 http://neuroscience.uth.tmc.edu 27 Dermatoms http://www.slideshare.net/drpsdeb/presentations 28 Dermatoms http://www.slideshare.net/drpsdeb/presentations http://www.slideshare.net/CsillaEgri/presentations 29 Trigeminal system http://www.slideshare.net/drpsdeb/presentations 30 Somatosensory pathways http://neuroscience.uth.tmc.edu/s2/chapter02.html 31 http://neuroscience.uth.tmc.edu 32 Thalamus a neocortex • Almost all the afferent information gated in the thalamus • Olfaction is an exception • Bilateral connections between neocortex and thalamus http://www.slideshare.net/drpsdeb/presentations 33 Neocortex http://www.shadmehrlab.org/Courses/physfound_files/wang_5.pdfhttp://www.slideshare.net/drpsdeb/presentations 34 Pain • Distressing feeling associated with real or potential tissue damage • Sensor x psychological component • Physiological x pathological pain • Acute (up to 6months) x chronic (more than 6 months) https://www.cheatography.com/uploads/davidpol_1460561912_Pain_Scale__Arvin61r58.png 35 Limbic system Navratilova E, Porreca F. Reward and motivation in pain and pain relief. Nat Neurosci. 2014;17:1304–1312. NAc – nucleus accumbens ACC – ant. Cingulate cortex. RVM – rostral ventromedial medulla 36 Descendent pathways modulating pain • Somatosemcoric cortex • Hypotalamus • Periaquaeductal gray • Nuclei raphe 37 Pain modulation on the spinal level Gate control theory of pain https://en.wikipedia.org/wiki/Gate_control_theory 38 Referred pain http://www.slideshare.net/drpsdeb/presentations 39 Phantom limb pain http://www.slideshare.net/drpsdeb/presentations 40