Somatosensory I PDF - 2018 MSB

Somatosensory I Brian J. Piper, PhD MS Office: MW 2:15 – 3:15 & by appointment 2018 MSB  COPYRIGHT All materials found on GCSoM’s course and project sites may be subject to copyright protection, and are restricted from further dissemination, retention or copying...

Somatosensory I Brian J. Piper, PhD MS Office: MW 2:15 – 3:15 & by appointment 2018 MSB  COPYRIGHT All materials found on GCSoM’s course and project sites may be subject to copyright protection, and are restricted from further dissemination, retention or copying. 2020  Disclosures BJP has received research support from non-profit (503-c) organizations for medical cannabis research and supplies from the National Institutes of Health. Pain and addiction research has been supported by Pfizer and the Health Resources & Services Administration.  Chapter 14 Learning Objectives Identify the neural substrates (cortical & subcortical) of pain. Appreciate the classical and non-classical neurotransmitters involved in pain. Contrast the distribution of the four different opiate receptors. Discuss different pain disorders including their substrates & treatments. Describe referred pain & the correspondence between internal vs external. Evaluate two commonly employed non-pharmacological interventions for pain (acupuncture & therapeutic touch). General Principles of Sensation Modality: specializations for pain, touch, pressure, temperature Intensity: strength of stimuli Duration: time of stimuli, adaptation Location Sensation ≠ perception Decussation? Thalamus Nuclei Function (N)/region Lateral Geniculate vision N Medial Geniculate audition N Anterior--------------Posterior Ventral pain Posterolateral various vestibular, taste,  Co-Transmitters Amine/Amino Neuropeptide Acid dopamine cholecystokinin (CCK) norepinephrine enkephalin epinephrine neurotensin serotonin substance P acetylcholine somatostatin GABA motilin l, S. (2000). Essential Psychopharmacology, p. 20.  Substrates of Pain I Periacqueductal Gray (PAG): Substance P: 11 amino acids, co-released with ______ Contains enkephalins Projects to medulla (raphe magnus) Locus Coeruleus (Siegel: ceruleus) Contains norepinephrine somas Projects to dorsal horn  Disclaimers for Pain Bio-psycho-social condition Important for survival and involves networks of brain areas. Mediated by localized groups of neurons, each with specific neurochemicals.  Substrates of Pain II Enkephalins bind to opiate receptors (metabotropic) mu (μ): widely distributed in brain (PAG, thalamus, striatum, locus coerleus) & dorsal horn of spinal cord, main receptor Autoradiography: histological technique to quantify receptor distribution autoradiography for μ in rat sour et al. Trends in Neuroscience 1988; 11:308-14.  Substrates of Pain II Enkephalins bind to opiate receptors (metabotropic) mu (μ): widely distributed in brain (PAG, thalamus, striatum, Locus Coerleus) & dorsal horn of spinal cord, main receptor Positron Emission Tomography for μ in human autoradiography for μ in rat  Substrates of Pain III PET for δ Enkephalins bind to opiate receptors (metabotropic) delta (δ), kappa, and nociceptin opioid receptor (NOR-R) have more restricted distributions, redundancy for mu cortex & insula HPC:______, CPU:_____, THL____ PRTX_____, GP_____, DR____, LC__________ nsour et al. Trends in Neuroscience 1988; 11:308-14. Madar et al. Synapse 1996; 24:19-28.  Nociceptin PET Ligand: nociceptin (17 amino acids) MRI Highest in caudate, lowest in cerebellum lith et al. J Nucl Med 2012; 53:385–392  Nociceptors Recep Fiber Diamet Myelinat Sensation tor grou er (μm) ed Type p mechanic Aδ 1-5 yes sharp, pricking al thermal Aδ 1–5 yes slow burning, cold sharp, pricking polymod C 0.5 - 2 no hot, burning, cold & mechanical al Cell bodies Dorsal Root Ganglia: body  Nociceptors Receptor Fiber Diameter Myelinated Sensation Type group (μm) mechanical Aδ 1-5 yes sharp, pricking thermal Aδ 1–5 yes slow burning, cold sharp, pricking polymodal C 0.5 - 2 no hot, burning, cold & mechanical Cell bodies Dorsal Root Ganglia: body Trigeminal Ganglia: face Ganglia are outside of the Blood Brain Barrier  Ascending Nociceptive Pathways Early Pain (Aδ) 1: nociceptor to dorsal horn 2: cross, ascend to thalamus (VPL) 3: Primary & Secondary Somatosensory Cortex ------ ventral posterolateral (VPL) nucleus yer et al. (2013). Psychopharmacology, Sinaur, p. 318.  Ascending Pathways (note error) Different red & blue than previous somatosensory homunculus  SI versus SII Primary Somatosensory Cortex (SI): Function is pain representation (contralateral) Secondary Somatosensory Cortex (SII): Located on dorsal surface of lateral sulcus Function is pain recognition (bilateral)  Ascending Nociceptive Pathways Late Pain (C) 1: nociceptor to dorsal horn 2: cross, ascend to thalamus (VPL) 3: Anterior Cingulate Cortex (ACC) for emotional component of pain ACC yer et al. (2013). Psychopharmacology, Sinaur, p. 318.  Referred Pain Pain arising from viscera is felt at surface Mechanism unknown. May involve convergence of axons from internal organs & skin at spinal cord  Pain Syndromes Phantom Limb Pain: pain from missing limb Treatment: mirror therapy Opioid-induced hyperalgesia: increased pain sensitization among patients on chronic opioid therapy, mechanism unknown (NMDA?) Treatment: switch opioid or ketamine Medication Overuse Headache: headache caused by overuse ( > 10 days/month) of various medications (triptans, caffeine, opioids), Treatment: discontinue undations of Neuroscience 2021 Stop HERE!!!!!! r Therapy (0 to 2:30): https://www.youtube.com/watch?v=hrqi1B9Xbt0 & Pryzbylkowski Pain Medicine 2015; 16:S32-36 Organization (disregard for 2021) Talk Paper Part 1-A secondary 1 (Pre) secondary or primary Part 1-B secondary 2 (Pre) secondary or primary Part 2-A secondary 3 (Pre) secondary or primary Part 2-B secondary 4 (In-class) secondary or primary #1 Part 3 Primary #1 or Case- secondary or primary Report #1 (In-class)  Fundamentals SCRIP of (2020) Neuroscience Length 2 pages / person, single- 5,000 words max spaced, title, abstract, conclusion Section Required Suggested Headings References AMA or Vancouver Vancouver Deadline April 1 (V1, optional) May 18 (?) April 15 (V2) Disregard for 2021 s://vtools.tcmc.edu/emailer/actions/display.php?id=39915  Vancouver References are listed in numerical order, and in the same order in which they are cited in text. The reference list appears at the end of the paper. Paper: The pathophysiology of migraine is poorly understood. Calcitonin gene related peptide (CGRP) is increased in saliva during migraine. Abbreviate journal as they are listed in Pubmed: https://www.ncbi.nlm.nih.gov/pubmed/ Journal of Neuroscience = J Neurosci Annals of Neurology = Ann Neurol Examples: #. Author of article AA, Author of article BB, Author of article CC. Title of article with non-proper nouns in lower case. Abbreviated Title of Journal. Year; vol(issue):page number start-end. 7. Piper BJ, DeKeuster RM, Beals ML, Cobb CM, Burchman CA, Perkinson L, et al. Substitution of medical cannabis for pharmaceutical agents for pain, anxiety, and sleep. J Psychopharmacolol. 2017; 31(5):569- 75. For other types, see: http://libguides.murdoch.edu.au/Vancouver/journal Be consistent! Appoint a group member for this  American Medical Association Cited works are numbered in order of initial appearance in the text, and appear in the Reference List in numerical order. The moon was thought to be made of green cheese.1,2 We now know that it is composed of chedder.3,4 Only first 6 authors followed by “et al.” Example: Rodriguez AB, Jones CD, Li EF, Assad GH, Hussain IJ, Victor KL, et al. Article title with non-proper nouns in lower case. Year; Abbreviated journal in italics Year; volume(issue):start page-end page (truncated). Yasen AL, Raber J, Miller JK, Piper BJ. Sex, but not apolipoprotein E polymorphism, differences in spatial performance in young adults. Arch Sex Behav 2015; 44(8):2219-26. Checklist Disregard for 2021 p://library.nymc.edu/informatics/amastyle.cfm Citation Shortcut Enter title into Google Scholar Click on “ Copy Vancouver Abbreviate journal: Prev Med Delete month Selecting A Primary Research Article High Impact Factor (IF) Journal preferred “meaty” with neuroscientific (mechanistic) data (figures > tables) Experimental preferred (control group) Replicated? Send to BP in advance (optional)  Pain Control & Acupuncture Chronic back pain patients (N = 638) completed a double-blind study with 6 licensed acupuncturists (4-19 years experience). Randomized to: Individualized Standardized Sham Usual Care IF = 16.5 rkin et al. Archives Int Med 2009; 169(9):858-866. Measuring Pain in Humans  Interpretation? Does it work better than control? rkin et al. Archives Int Med 2009; 169(9):858-866.  Does it work better than control? No rkin et al. Archives Int Med 2009; 169(9):858-866.  Therapeutic Touch Why was this study done? What was done? What was found? So? (what are the implications?) Limitations? Future directions? sa et al. (1998). JAMA, 279, 1005-1010.  Therapeutic Touch osa et al. (1998). JAMA, 279, 1005-1010.  Did therapeutic touch work? No ---------------------------------------------------------- et al. (1998). JAMA, 279, 1005-1010. o (0 to 3:05): https://www.youtube.com/watch?v=mNoRxCRJ-Y0