Neural connections associated with sensory signals from fascia, vasculature, and affective touch receptors - webinar by Prof.Dr. Rick Johnson 19th Oct 2022 (ENGLISH)

19th October 20h

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Neural connections associated with sensory signals from fascia, vasculature, and affective touch receptors webinar via ZOOM by Prof.Dr. Rick Johnson 19th Oct 2022

45 min webinar with 15 min questions (human topic)

Neural connections associated with sensory signals from fascia, vasculature, and affective touch receptors

In this webinar, I will discuss the neural connections associated with sensory signals from fascia, vasculature, and affective touch receptors in animals.  The sensory neurons innervating these structures have not been extensively studied despite their importance in physiological and emotional fitness.  However, recent studies of all of these tissues by our laboratory and labs of others, have given us a greater understanding of their roles. 

Fascia can be considered as a distinct organ system because it has a distinct (a) blood supply, (b) nerve supply, (c) function, (d) anatomy (morphology).  Sensory neurons innervating fascia are (i) large myelinated axons associated with sophisticated sense organs, and (ii) small myelinated and unmyelinated axons associated with free nerve endings.  The motor neurons innervating fascia are small unmyelinated sympathetic postganglionic axons.  I will discuss their central connections/circuits and their functional responses and reflexes.  For example, protective reflexes initiated from fascia receptors (spasms, body armour and guarding reflexes) are often triggered by myelinated (Golgi tendon organs, Ruffini endings in joint capsule, SAII Ruffini endings in deep skin) and unmyelinated collagen-intertwined free nerve endings.  Improper tissue gliding is directly related to development of mechanoreceptive and proprioceptive insufficiency and muscle incoordination.

The functional roles of visceral sensory neurons innervating the vasculature and visceral organs have been elusive, in part, because there is a lack of perceptual awareness in normal conditions, they are difficult to study, the central and peripheral circuitry is complicated, and their continuous plasticity alters their impact on health, disease, and aging.  Their route to the CNS has an impact on their role in visceral pain perception, that is, visceral sensory axons traveling in sympathetic nerve trunks (e.g. sympathetic trunk) can lead to perceived visceral pain, whereas those traveling in parasympathetic nerve trunks (e.g. vagus) are primarily performing unperceived regulatory functions.  Input from vascular sensory neurons has been implicated in migraine headache and deep tissue pain (including fibromyalgia).  Vascular nociceptors acting as chemoreceptors have been shown to sense changes in hydrogen ion concentrations which can be elicited by changes in blood flow and can lead to deep tissue pain.  We have shown that vascular nociceptor activation may explain the persistent headache, chest pain, and widespread joint/muscle pain that have been extensively documented in cases involving exposure to environmental toxins. 

Recently, a specialized sensory system in the skin of animals and humans has been discovered that is important in the emotional system of affective touch.  Signaled by low threshold tactile unmyelinated C-fibers responsive to only slow skin-stroking stimuli (e.g. petting your dog), these sensory signals have unusual central projection patterns.  For example, imaging studies show cortical projections to emotional (limbic) centers with minimal or absent projection to the somatosensory cortex.  This system may have developed to promote interpersonal bonding through touch.  New data suggests presence of similar sensory neurons within muscle fascia, activated by massage.  The affective touch system may also have a role in healing, immune function, and emotional support (human-animal bond).

For more information contact: - slides will be provided after the webinar

Learning objectives :

  • Be able to explain osteopathic effects according to nowadays knowledge
  • Be able to specify what effect is a specific or non-specific effect

Presentation of Dr. Rick Johnson

Dr. Rick Johnson is a Professor of Veterinary Anatomy and Neuroscience at the University of Florida College of Veterinary Medicine.  He received his anatomical and neuroscience training at the University of California, Davis, School of Veterinary Medicine.  He teaches a number of courses at the University of Florida, including Equine Anatomy, Equine Lameness and Imaging, and Veterinary Neuroscience.  His expertise area is primarily the peripheral nerves of domesticated animals (large and small animals), in addition to primates and humans. and how these sensory and motor neurons interact with central and peripheral neural circuits and reflexes.  His research investigations, in animal models, include how somatic and visceral neural circuits are affected by spinal cord/peripheral nerve traumatic injury or pathology.  His expertise/interests includes the autonomic nervous system and how it interconnects peripheral organs with the brain/spinal cord via viscerosomatic neurons.  Current projects include investigations of the sensory innervation of the vasculature, fascia, and specialized “affective touch” receptors in the skin.