Summary
The distribution of calcitonin gene-related peptide (CGRP)-immunoreactive nerve fibres in the palate of rat, cat and monkey was studied using immunocytochemistry and radioimmunoassay.
CGRP-containing nerve fibres were found, in all species studied, to form a rich plexus in the subepithelial and submucous layers, around excretory ducts and blood vessels. A small number of CGRP-containing nerve fibres penetrated the epithelium of the hard and soft palate, and terminated as free endings. Some CGRP-containing nerve fibres were found in the vicinity of the mucous glands. CGRP-immunoreactive motor end plates were seen in the striated muscle (tensor veli palatini) of the soft palate.
Following capsaicin treatment a small depletion in CGRP-immunoreactive nerve fibres in the rat palate epithelium was noted. In contrast, CGRP immunoreactive fibres forming rich plexuses in other layers of the palate, including motor end plates, were not affected. The extractable CGRP showed no significant depletion (normal animals [n=10] 21.7±2.4 pmol/g compared with capsaicin-treated animals [n=10] 17.5±1.8 pmol CGRP/g wet weight). The reduction in the number of visible immunoreactive nerves following capsaicin application tends to confirm the sensory character of the CGRP-containing nerve fibres terminating in the epithelium of the hard and soft palate. The capsaicin insensitive CGRP-immunoreactive nerve fibres may thus have a predominantly motor function.
The unilateral section of the mandibulary division of trigeminal, hypoglossal, glossopharyngeal and superior laryngeal nerve caused a depletion of variable severity in the ipsilateral CGRP-immunoreactive nerve fibres in the epithelium, subepithelial and periductal plexus and in motor end plates.
These findings are in agreement with the radioimmunoassay results, which detect 22.7±1.0 pmol/g in normal tissues, 19.7±1.0 pmol/g after section of trigeminal nerve, and 18.6±1.2 pmol/g after simultaneous sectioning of the trigeminal, hypoglossal, glossopharyngeal, laryngeal and recurrent nerves. We conclude that CGRP is present in both sensory and motor components of cranial nerves which innervate the palate.
Similar content being viewed by others
References
Amara SG, Jonas V, Rosenfeld MG, Ong ES, Evans RM (1982) Alternative RNA processing in calcitonin gene expression generates in RNAs encoding different polypeptide products. Nature 298:240–244
Avramcas S, Ternynch T (1969) Cross-linking of proteins with glutaraldehyde and its use for the preparation of immunoabsorbants. Immunochemistry 6:53–66
Botezat E (1901) Die Innervation des harten Gaumens der Säugetiere. Z Wiss Zool 69:429–443
Botezat E (1903) Über die epidermoidalen Tastapparate in der Schnauze des Maulwurfs und anderer Säugetiere mit besonderer Berücksichtigung derselben für die Phylogenie der Haare. Arch Microsc Anat 61:730
Botezat E (1906) Die Nervenendapparate in den Mundteilen der Vögel und die einheitliche Endigungsweise der peripheren Nerven bei den Wirbeltieren. Z Wiss Zool 84:205–360
Bromhead IW (1951) The nerve supply of the muscle of the soft palate. Br J Plast Surg 4:1–15
Bryant MG, Bloom SR (1982) Measurement in tissue. In: Bloom SR, Long RG (eds) Radioimmunoassay of gut regulatory peptides. WB Saunders, London Philadelphia Toronto, pp 36–41
Fitzgerald M (1983) Capsaicin and sensory neurons. Pain 15:109–130
Gairns FW (1951) Nerve endings in the human gum and hard palate. J Physiol 115:70p
Gairns FW (1954) Sensory nerve endings in the human palate. J Physiol 123:26–27 p
Gairns FW (1955) The sensory nerve endings of the human palate. Q J Exp Physiol 40:40–48
Greene EC (1963) Anatomy of the rat. In: Transactions of the American Philosophical Society, vol 27. Hafner, New York London, pp 115–137
Jancso G, Kiraly E (1981) Sensory neurotoxins: chemically induced selective destruction of primary sensory neurons. Brain Res 210:83–89
Kadanoff D (1927) Über die intraepithelialen Nerven und ihre Endigungen beim Menschen und bei den Säugetieren. Z Zellforsch Mikrosk Anat 7:553–575
Lalonde ER, Eglitis JA (1961) Number and distribution of taste buds on the epiglottis, pharynx, larynx, soft palate and uvula in a human newborn. Anat Rec 140:91–95
Nagy JI, Hunt SP, Iversen LL, Empson P (1981) Biochemical and anatomical observations on the degeneration of peptide-containing primary afferent neurons after neonatal capsaicin. Neuroscience 6:1923–1934
Norgren R (1974) Gustatory afferents to ventral forebrain. Brain Res 81:285–295
Norgren R (1974) Gustatory afferents to ventral forebrain. Brain Res 81:285–295
Norgren R, Leonard CM (1964) Ascending central gustatory pathways. J Comp Neurol 160:217–238
Ogawa H, Akagi T (1978) Afferent connections to the posteriomedial ventral nucleus from the pons and the rostral medulla in the rat. Kumamoto Med J 31:54–62
Ogawa H, Hayama T (1981) Receptove fields of neurons in the rostral part of the nucleus tractus solitarius in rats. Neurosci Lett (Suppl) 65:102
Ogawa H, Imoto T, Hayama T (1980) Taste relay neurons in the solitary tract nucleus of rats. Neurosci Lett 18:295–299
Ogawa H, Hayama T, Ito S (1982) Convergence of input from tongue and palate to the parabrachial nucleus neurons of rats. Neurosci Lett 2:9–14
Rodrigo J, Hernandez CJ, Vidal MA, Pedrosa JA (1975) Vegetative innervation of the oesophagus. III Intraepithelial endings. Acta Anat 92:242–258
Rodrigo J, Polak JM, Fernandez L, Ghatei MA, Mulderry P, Bloom SR (1985) Calcitonin gene-related peptide (CGRP) immunoreactive sensory and motor nerves of the rat, cat and monkey oesophagus. Gastroenterology (in press)
Rosenfeld MG, Mermod JJ, Amara SG, Swanson LW, Sawchenko PE, Rivier J, Vale WW, Evans RH (1983) Production of a novel neuropeptide encoded by the calcitonin gene via tissuespecific RNA processing. Nature 304:129–135
Scadding JW (1980) The permanent anatomical effects of neonatal capsaicin on somatosensory nerves. J Anat 131:473–484
Stöhr P (1951) Lehrbuch der Histologie. Springer, Berlin Heidelberg New York
Terenghi G, Polak JM, Probert L, McGregor GP, Ferri GL, Blank MA, Butler JM, Unger WG, Shu-gi Zhang, Cole DF, Bloom SR (1982) Mapping, quantitative distribution and origin of substance P- and VIP-containing nerves in the uvea of guinea pig eye. Histochemistry 75:399–417
Williams PL, Warwick R (eds) (1980) Gray's anatomy. Churchill Livingstone, New York
Author information
Authors and Affiliations
Additional information
J. Rodrigo is a visiting Professor from Instituto Santiago Ramon y Cajal, Madrid, Spain and has a Fellowship from the Royal Society
Rights and permissions
About this article
Cite this article
Rodrigo, J., Polak, J.M., Terenghi, G. et al. Calcitonin gene-related peptide (CGRP)-immunoreactive sensory and motor nerves of the mammalian palate. Histochemistry 82, 67–74 (1985). https://doi.org/10.1007/BF00502092
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00502092