Elsevier

Brain Research

Volume 117, Issue 2, 26 November 1976, Pages 211-226
Brain Research

Inputs to trigeminal brain stem neurones from facial, oral, tooth pulp and pharyngolaryngeal tissues: I. responses to innocuous and noxious stimuli

https://doi.org/10.1016/0006-8993(76)90731-9Get rights and content

Abstract

Responses evoked in anaesthetized or decerebrate cats by stimulation of efferents supplying the face, mouth, pharynx, larnyx, tooth pulp and jaw muscles were recorded from single neurones located in the trigeminal (V) main sensory nucleus, V nucleus oralis, and adjacent regions. Many cells (both V-thalamic relay and non-relay) with localized V mechanoreceptive cutaneous fields could be activated by stimulation of a number of these afferents. A particularly prominent short-latency (often monosynaptic) input was noted from the canine tooth pulp, stimulation of which is generally considered to elicit only responses of pain in man. Control experiments showed that pulp-evoked responses were not the result of stimulus spread to tissues outside the pulp. The interaction of these various inputs to neurones at this level of the V brain stem complex typically resulted in a prolonged period of inhibition that was sometimes preceded by a short-lasting facilitatory phase. This inhibitory effect was also apparent in neurones located outside the complex, although a late facilitatory phase was frequently also noted. Our findings indicate a significant nociceptive input to V main sensory-oralis neurones, a proportion of which relay directly to the ventrobasal thalamus. The interactions described may be involved in perceptual and reflex aspects of responses to noxious and innocuous V stimuli.

Reference (32)

  • NordS.G. et al.

    Projection of tooth pulp afferents to the cat trigeminal nucleus caudalis

    Brain Research

    (1975)
  • RoweM.J. et al.

    Responses of trigeminal ganglion and brain stem neurones in the cat to mechanical and thermal stimulation of the face

    Brain Research

    (1972)
  • SessleB.J.

    Excitatory and inhibitory inputs to single neurones in the solitary tract nucleus and adjacent reticular formation

    Brain Research

    (1973)
  • YokotaT.

    Excitation of units in marginal rim of trigeminal subnucleus caudalis elicited by tooth pulp stimulation

    Brain Research

    (1975)
  • AndersonD.J. et al.

    Sensory mechanisms in mammalian teeth and their supporting structures

    Physiol. Rev.

    (1970)
  • DaviesW.I.R. et al.

    Depolarization of the tooth pulp afferent terminals in the brain stem of the cat

    J. Physiol. (Lond.)

    (1971)
  • Cited by (176)

    • Altered Brainstem Pain Modulating Circuitry Functional Connectivity in Chronic Painful Temporomandibular Disorder

      2021, Journal of Pain
      Citation Excerpt :

      Interestingly, we found FC alterations were restricted to the rostral portion of SpV in the oralis division. This was surprising, given that the SpVo is typically associated with nociceptive processing in oral and perioral regions,55,56 and that it has previously been shown that TMD subjects show anatomical changes and increases in ongoing blood flow in the caudalis region of SpV.66,68 Whilst we do not know why these local differences occur, it has been shown that the SpV caudalis can modulate orofacial sensory information via projections to the SpV oralis,20 and a large proportion of primary afferent nerve fibres from the temporomandibular joint itself terminate in the SpVo.11

    • 5.31 - Dental Pain Mechanisms

      2020, The Senses: A Comprehensive Reference: Volume 1-7, Second Edition
    • 3.20 - Oral Chemesthesis and Taste

      2020, The Senses: A Comprehensive Reference: Volume 1-7, Second Edition
    • Somatosensory changes in orthodontics—findings from quantitative sensory testing (QST) studies

      2018, Seminars in Orthodontics
      Citation Excerpt :

      These results support the occurrence of neuroplastic changes in the central and peripheral nervous system as a result of the periodontalnoxious stimuli.37 One possible hypothesis for this finding is that the peripheral inflammatory condition, due to the separator wearing, stimulates the discharge of wide dynamic range and nociceptive specific neurons in the trigeminal nucleus caudalis.39 PPTs were also measured in subjects with a history of orthodontic treatment, who ended the therapy about 5years before the study.

    View all citing articles on Scopus
    View full text