» Articles » PMID: 9409481

Relationship of Substance P to Afferent Characteristics of Dorsal Root Ganglion Neurones in Guinea-pig

Overview
Journal J Physiol
Specialty Physiology
Date 1997 Dec 31
PMID 9409481
Citations 99
Authors
Affiliations
Soon will be listed here.
Abstract

1. The relationship between the afferent properties and substance P-like immunoreactivity (SP-LI) of L6 and S1 dorsal root ganglion (DRG) neuronal somata was examined in anaesthetized guinea-pigs. Glass pipette microelectrodes filled with fluorescent dyes were used to make intracellular recordings and to label DRG somata. The dorsal root conduction velocity (CV) and the afferent receptive properties of each unit were categorized according to criteria established in other species. Categories included a variety of low threshold mechanoreceptive classes, innocuous thermoreceptive and several nociceptive classes. Nociceptive units were further subdivided on the basis of CV and the locus of the receptive field (superficial cutaneous, deep cutaneous or subcutaneous). 2. SP-LI was determined using the avidin-biotin complex method and the relative staining intensity determined by image analysis. The possible significance of labelling intensity is discussed. Clear SP-LI appeared in twenty-nine of 117 dye-labelled neurones. All SP-LI positive units with identified receptive properties were nociceptive but not all categories of nociceptors were positive. The intensity of SP-LI labelling varied, often systematically, in relation to afferent properties. There was a tendency for nociceptive neurones with slower CVs and/or smaller cell bodies to show SP-LI. 3. Nineteen of fifty-one C fibre neurones showed SP-LI. Fewer than half the C polymodal nociceptors (CPMs) were positive. The most intensely labelled units were the deep cutaneous nociceptors and some of the CPMs in glabrous skin. C low threshold mechanoreceptors and cooling-sensitive units did not show SP-LI. 4. Ten of sixty-six A fibre neurones exhibited SP-LI, including eight of sixteen A delta nociceptors and two of fifteen A alpha/beta nociceptors. A fibre neurones exhibiting SP-LI included seven of eight deep cutaneous mechanical nociceptors and some superficial cutaneous mechano-heat nociceptors of hairy skin. In contrast, none of twenty superficial cutaneous A high threshold mechanoreceptor units or the thirty-five A fibre low threshold units (D-hair and other units) showed detectable SP-LI. 5. We conclude that SP-LI labelling in guinea-pig DRG neurones is related to (a) afferent receptive properties, (b) the tissue in which the peripheral receptive terminals are located, (c) the CV and (d) the soma size.

Citing Articles

Spinal Nerve Axotomy: Effects on I In Vivo and HCNs in DRG Neurons.

Song Y, Gao L Int J Mol Sci. 2024; 25(23).

PMID: 39684600 PMC: 11641092. DOI: 10.3390/ijms252312889.


Insecure Attachment, Oxytocinergic System and C-Tactile Fibers: An Integrative and Translational Pathophysiological Model of Fibromyalgia and Central Sensitivity Syndromes.

Bruti G, Foggetti P Biomedicines. 2024; 12(8).

PMID: 39200209 PMC: 11351601. DOI: 10.3390/biomedicines12081744.


Distribution and Chemistry of Phoenixin-14, a Newly Discovered Sensory Transmission Molecule in Porcine Afferent Neurons.

Mazur U, Lepiarczyk E, Janikiewicz P, Lopienska-Biernat E, Majewski M, Bossowska A Int J Mol Sci. 2023; 24(23).

PMID: 38068975 PMC: 10706208. DOI: 10.3390/ijms242316647.


Analgesic dorsal root ganglion field stimulation blocks both afferent and efferent spontaneous activity in sensory neurons of rats with monosodium iodoacetate-induced osteoarthritis.

Chao D, Tran H, Hogan Q, Pan B Osteoarthritis Cartilage. 2022; 30(11):1468-1481.

PMID: 36030058 PMC: 9588581. DOI: 10.1016/j.joca.2022.08.008.


Wnt Signaling Pathways: A Role in Pain Processing.

Tang Y, Chen Y, Liu R, Li W, Hua B, Bao Y Neuromolecular Med. 2022; 24(3):233-249.

PMID: 35067780 PMC: 9402773. DOI: 10.1007/s12017-021-08700-z.


References
1.
BURGESS P, Perl E . Myelinated afferent fibres responding specifically to noxious stimulation of the skin. J Physiol. 1967; 190(3):541-62. PMC: 1365427. DOI: 10.1113/jphysiol.1967.sp008227. View

2.
Otsuka M, Yoshioka K . Neurotransmitter functions of mammalian tachykinins. Physiol Rev. 1993; 73(2):229-308. DOI: 10.1152/physrev.1993.73.2.229. View

3.
Stefanini M, De Martino C, Zamboni L . Fixation of ejaculated spermatozoa for electron microscopy. Nature. 1967; 216(5111):173-4. DOI: 10.1038/216173a0. View

4.
Bessou P, Perl E . Response of cutaneous sensory units with unmyelinated fibers to noxious stimuli. J Neurophysiol. 1969; 32(6):1025-43. DOI: 10.1152/jn.1969.32.6.1025. View

5.
Bessou P, BURGESS P, Perl E, Taylor C . Dynamic properties of mechanoreceptors with unmyelinated (C) fibers. J Neurophysiol. 1971; 34(1):116-31. DOI: 10.1152/jn.1971.34.1.116. View