Features of structure of motor nerve endings in the tongue of normal and dehydrated rats

Keywords: nerve-muscle endings, tongue, muscle fibres, dehydration, rats


This study aims at an analytical review of scientific literature on the structure of the tongue of different animals and humans, and also at studying the features of the structure of motor nerve endings in the tongue muscles of healthy rats and rats that have undergone prolonged dehydration. Over 14 days, using histological methods we studied neuromuscular endings and peculiarities of their distribution in the tongue muscles of 25 mature rats, both in normal condition and under dehydration. The analysis of the results showed different structures of differentiated motor nerve endings among the rats in normal condition, and also revealed the peculiarities and quantitative characteristics of the components of the neuromuscular endings in relation to the duration of dehydration. The type of neuromuscular ending reflects the morphologically interdependent structure of efferent neuromediators in relation to a part of the tongue. This may determine the nature of the processes of prehension and chewing of food. The structure of neuromuscular endings of the muscles of the tip of the tongue is the most differentiated, they are more numerous and larger. The tip of the tongue of rats had a higher number of nuclei and larger size of the neuromuscular endings of the muscles than the other parts. This, perhaps, is determined by the speed of the movements of the tongue due to eating different foods. The number of nuclei and the size of neuromuscular endings are characterized by significant variations in the pattern of axon branching, which is determined by the anatomical, physiological and biomechanical conditions of functioning of the rats’ tongue muscles. The quantitative analysis of structural peculiarities of axomycin synapses showed that muscle fibers of the tongue have neuroumuscular endings with regulated synaptoarchitectonics which is characterized by the sprouting of the motor axon, a certain length and width of the active zones, number and size of the synaptic folds, number of terminal neurolemmocytes, and the peculiarity in structure of the subsynaptic area. Muscle fibers in the body of the tongue have the most complex special distribution of presynaptic pole of axomuscular synapses, they also have the highest number of active zones and synaptic folds. We determined the main reactive and destructive processes while distinguishing certain phases of morphologically-functional changes in the organism under total dehydration. A complex analysis of the morpho-functional characteristics of the peripheral nervous apparatus of the tongue of rats subject to total dehydration helped reveal the structural rearrangement of the neuromuscular endings over certain periods. During first three days after the beginning of the dehydration modeling, a structural adaptation was manifested in the reorganization of the neuromuscular endings, which was followed by their destructive changes in 6–9 days, and a phase of exhaustion with disorders in the fine architectonics of neuromuscular endings after 14 days. The article discusses the peculiarities of the efferent part of the motor unit of the tongue of rats subject to prolonged dehydration. 


Amir, O., & Grinfeld, D. (2011). Articulation rate in childhood and adolescence: Hebrew speakers. Language and Speech, 54(2), 225–240.

Bayline, R. J., Duch, С. C., & Levine, R. B. (2001). Nerve-muscle interactions regulate motor terminal growth and myoblast distribution during muscle development. Developmental Biology, 231, 348–363.

Bunn, D., Jimoh, F., Wilsher, S., & Hooper, L. (2014). Effectiveness of external fac tors to reduce the risk of dehydration in older people living in residential care: A systematic review. BMC Health Services Research, 14(Suppl 2), P11.

Choy, V. J. (1986). Isolation and properties of sheep neurohypophysial nerve ter minals. Neuropeptides, 7(4), 337–349.

Dana, R. M., & McCaughey, S. A. (2015). Gustatory responses of the mouse chorda tympani nerve vary based on region of tongue stimulation. Chemical Senses, 40(5), 335–344.

Davidova, L. M., Tkach, G. F., Sіkora, V. Z., Kіptenko, L. І., & Maksimova, O. S. (2016). Dinamіka strukturnoji organіzacіji jazyka shhurіv za umov vplivu zagal’nogo znevodnennja organіzmu [The dynamics of the structural organization of tongue of rats under the influence of general dehydration]. Aktual’nі Problemy suchasnoji Medicyny, 16(4), 8–12 (in Ukranian).

Fritz, M., & Müller, V. (2007). An intermediate step in the evolution of ATPases – F1F0-ATPase from Acetobacterium woodii contains F-type and V-type rotor subunits and is capable of ATP synthesisthe. FEBS Journal, 274(13), 3421–3428.

Gaffield, M. A., Romberg, C. F., & Betz, W. J. (2011). Live imaging of bulk endocytosis in frog motor nerve terminals using FM dyes. Journal of Neurophysiology, 106(2), 599–607.

García, M. R., Pearlmutter, B. A., Wellstead, P. E., & Middleton, R. H. (2013). A slow axon antidromic blockade hypothesis for tremor reduction via deep brain stimulation. PLoS ONE, 8(9), 734–756.

Guttridge, D. C. (2012). Skeletal muscle regeneration. In: Hill, J. (ed.). Muscle. Fundamental Biology and Mechanisms of Disease. Elsevier, 2, 921–933.

Holstege, J. C., & Kuypers, H. G. J. M. (1987). Brainstem projections to lumbar motoneurons in rat – I. An ultrastructural study using autoradiography and the combination of autoradiography and horseradish peroxidase histochemistry. Neuroscience, 21(2), 345–367.

Hooper, L., & Bunn, K. (2014). Predictors of dehydration in older people living in UK residential care. European Geriatric Medicine, 5, 202–203.

Hooper, L., Bunn, D., Jimoh, F. O., & Fairweather-Tait, S. J. (2014). Water-loss dehydration and aging. Mechanisms of Ageing and Development, 136, 50–58.

Hooper, L., Bunn, K., Prado, M., & Siervo, M. (2014). Assessment of dehydration in older people: Agreement of measured serum osmolality with calculated serum osmolarity equations. European Geriatric Medicine, 5, 80.

Hua, T. E., Yang, T. L., Yang, W. C., Liu, K. J., & Tang, S. C. (2013). 3-D neurohistology of transparent tongue in health and injury with optical clearing. Frontiers Neuroanatomy, 7, 36–42.

Johansson, G. S., & Arnqvist, H. J. (2006). Insulin and IGF-I action on insulin receptors, IGF-I receptors, and hybrid insulin/IGF-I receptors in vascular smooth muscle cells. AJP: Endocrinology and Metabolism, 291(5), 1124–1130.

Johnstone, A. F. M., Viele, K., & Cooper, R. L. (2010). Structure/function assessment of synapses at motor nerve terminals. Synapse, 65(4), 287–299.

Knittel, L. M., & Kent, K. S. (2005). Remodeling of an identified motoneuron during metamorphosis: Hormonal influences on the growth of dendrites and axon terminals in fish. Journal of Neurobiology, 63(2), 106–125.

Kuznetsov, I. A., & Kuznetsov, A. V. (2014). What tau distribution maximizes fast axonal transport toward the axonal synapse? Mathematical Biosciences, 253, 19–24.

Liu, Z.-J., Shcherbatyy, V., Kayalioglu, M., & Seifi, A. (2009). Internal kinematics of the tongue in relation to muscle activity and jaw movement in the pig. Journal of Oral Rehabilitation, 36(9), 660–674.

Moore, D. L., & Goldberg, J. L. (2011). Multiple transcription factor families regulate axon growth and regeneration. Developmental Neurobiology, 71(12), 1186–1211.

Mosendz, T. M., & Mickan, B. M. (2012). Struktura skeletnogo m’jaza pri termo robochіj degіdratacіji organіzmu [The structure of skeletal muscle during termal dehydration]. Morfologіja, 94(1), 150–153 (in Ukranian).

Motoyama, A. A., Watanabe, I. S., Iyomasa, M. M., Silva, M. C. P., Sosthines, M. C. K., Lopes, M. G. O., Guimarães, J. P., & Kfoury, J. R. (2009). Ultrastructure of motor nerve terminals in the anterior third of wistar rat tongue. Microscopy Research and Technique, 72(6), 464–470.

Mu, L., & Sanders, I. (2010). Human tongue neuroanatomy: Nerve supply and motor endplates. Clinical Anatomy, 23(7), 777–791.

Mu, L., Sobotka, S., Chen, J., Su, H., Sanders, I., Adler, C. H., Shill, H. A., Cavi ness, J. N., Samanta, J. E., & Beach, T. G. (2013). α-Synuclein pathology and axonal degeneration of the peripheral motor nerves innervating tongue muscles in Parkinson Disease. Journal of Neuropathology and Experimental Neurology, 72(2), 119–129.

Nawaz, S., Schweitzer, J., Jahn, O., & Werner, H. B. (2013). Molecular evolution of myelin basic protein, an abundant structural myelin component. Glia, 61(8), 1364–1377.

Pathi, B., Kinsey, S. T., Howdeshell, M. E., Priester, C., McNeill, R. S., & Locke, B. R. (2012). The formation and functional consequences of heterogeneous mitochondrial distributions in skeletal muscle. Journal of Experimental Biology. 215(11), 1871–1883.

Pfeiffer, C. J., Levin, M., & Lopes, M. A. F. (2000). Ultrastructure of the horse tongue: Further observations on the lingual integumentary architecture. Ana tomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C, 29(1), 37–44.

Robin, M., Malbon, A., Ricci, E., McGowan, C., & Malalana, F. (2013). Reduced tongue tone associated with degeneration of the hypoglossal nerve nucleus in a horse with equine motor neuron disease. Equine Veterinary Education, 28(8), 434–438.

Rothman, J. (2013). Control of membrane fusion in exocytosis. Biophysical Journal, 104(2), 11a.

Simmons, Z. (2016). Changes in muscle and Nerve. Muscle and Nerve, 55(1), 1–2.

Simmons, Z. (2017). The scope of muscle and nerve. Muscle and Nerve, 55(5), 615–616.

Slater, C. R. (2015). The functional organization of motor nerve terminals. Progress in Neurobiology, 134, 55–103.

Slaughter, K., Li, H., & Sokoloff, A. J. (2006). Neuromuscular organization of the superior longitudinalis muscle in the human tongue 1. Motor endplate mor phology and muscle fiber architecture. Cells Tissues Organs, 181(1), 51–64.

Suzuki, E., Aoyama, K., Fukui, T., Nakamura, Y., & Yamane, A. (2012). The function of platelet-derived growth factor in the differentiation of mouse ton gue striated muscle. Orthodontics and Craniofacial Research, 15(1), 39–51.

Tankisi, H., Otto, M., Pugdahl, K., & Fuglsang-Frederiksen, A. (2013). Sponta neous electromyographic activity of the tongue in amyotrophic lateral sclerosis. Muscle and Nerve, 48(2), 296–298.

Watanabe, I., Guimarães, J. P., Boleta Almeida, S. A. Y., Righeti, M. M., Santos, T. C., Miglino, M. A., & Kfoury, J. R. (2009). Nerve endings of filliform, fungiform and vallate papillae of dorsal tongue mucosa of White-lipped peccary (Tayassu pecari): Neurohistological observations. Pesquisa Veteri nária Brasileira, 29(4), 281–285.

Ye, W., Abu, A. F., & Liu, Z. J. (2010). Assessment of cell proliferation and muscular structure following surgical tongue volume reduction in pigs (guineia pigs). Cell Proliferation, 43(6), 562–572.

Zciena, A. P., Bolina, C. S., Almeida, S. R. Y., Rici, R. E. G., Oliveira, M. F., Silva, M. C. P., Miglino, M. A., & Watanabe, I. S. (2013). Structural and ultrastructural features of the agouti tongue (Dasyprocta aguti Linnaeus 1766). Journal of Anatomy, 223,(2), 152–158.

Zghikh, L. N., Vangysel, E., Nonclercq, D., Legrand, A., Blairon, B., Berri, C., Bordeau, T., Rémy, C., Burtéa, C., Montuelle, S. J., & Bels, V. (2014). Morphology and fibre-type distribution in the tongue of the Pogona vitticeps lizard (Iguania, Agamidae). Journal of Anatomy, 225(4), 377–389.

Zhang, L. F., Moritani, M., Honma, S., Yoshida, A., & Shigenaga, Y. (2001). Quantitative ultrastructure of slowly adapting lingual afferent terminals in the principal and oral nuclei in the cat. Synapse, 41(2), 96–111.

How to Cite
Popel’, S. L., BylоusО. Т., & Bylous, I. V. (2017). Features of structure of motor nerve endings in the tongue of normal and dehydrated rats. Regulatory Mechanisms in Biosystems, 8(3), 333-342. https://doi.org/10.15421/021772