The rat anococcygeus muscle, which is known from previous functional and histochemical investigations to be a smooth muscle with a dense adrenergic innervation, was studied by electron microscopic methods. The muscle was found to be organized in small bundles of 2 to 8 muscle cells, which were interconnected by desmosome-like junctions and by gap junctions. Small Schwann cell-axon complexes with 1 to 5 axons appeared to represent the functional terminal nerve pathway. Such axon complexes were located at the periphery of the small smooth muscle bundles, they never penetrated into them. A ratio of approximately 6 small axon complexes per 100 muscle cells was found. After glutaraldehyde fixation axon varicosities contained mainly small empty vesicles. After treatment with 5-hydroxydopamine and permanganate fixation mainly small vesicles with a dense core were found. The neuromuscular distances ranged from 550 to 5000 Å, with a mean of about 2600 Å. True close neuromuscular contacts at a distance below 500 Å with a fusing of basal laminae were absent.
The present observations provide a morphological base for the findings of previous electrophysiological and pharmacological studies on the anococcygeal muscle.
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Bell, C.: An electrophysiological study of the effects of atropine and physostigmine on transmission to the guinea-pig vas deferens. J. Physiol. (Lond.) 189, 31–42 (1967)
Bennett, M. R.: Autonomic neuromuscular transmission, chapter 1. Cambridge, England: Cambridge Univ. Press 1972
Burnstock, G.: Structure of smooth muscle and its innervation. In: Smooth muscle, p. 1–69, eds. Bülbring, E., Brading, A. F., Jones, A. W., Tomita, T. London: Arnold 1970
Burnstock, G.: Purinergic nerves. Pharmacol. Rev. 24, 509–581 (1972)
Burnstock, G., Prosser, C. L.: Conduction in smooth muscles: comparative electrical properties. Amer. J. Physiol. 199, 553–559 (1960)
Devine, C. E., Simpson, F. O.: The fine structure of vascular sympathetic neuromuscular contacts in the rat. Amer. J. Anat. 121, 153–174 (1967)
Devine, C. E., Somlyo, A. V., Somlyo, A. P.: Sarcoplasmic reticulum and mitochondria as cation accumulation sites in smooth muscle. Phil. Trans. B 265, 17–23 (1973)
Dewey, M. M., Barr, L.: Intercellular connection between smooth muscle cells: the nexus. Science 137, 670–672 (1962)
Esterhuizen, A. C., Graham, J. D. P., Lever, J. D., Spriggs, T. L. B.: Catecholamine and acetylcholinesterase distribution in relation to noradrenaline release. An enzyme histochemical and autoradiographic study on the innervation of the cat nictitating muscle. Brit. J. Pharmacol. 32, 46–56 (1968)
Evans, D. H. L., Evans, E. M.: The membrane relationships of smooth muscles: an electronmicroscope study. J. Anat. (Lond.) 98, 37–46 (1964)
Gabella, G.: Caveolae intracellulares and sarcoplasmic reticulum in smooth muscle. J. Cell Sci. 8, 601–609 (1971)
Gabella, G.: Intercellular junctions between circular and longitudinal intestinal muscle layers. Z. Zellforsch. 125, 191–199 (1972)
Gabella, G.: Cellular structures and electrophysiological behaviour. Phil. Trans. B 265, 7–16 (1973)
Gibson, A., Gillespie, J. S.: The effect of immunosympathectomy and of 6-hydroxydopamine on the responses of the anococcygeus to nerve stimulation and to some drugs. Brit. J. Pharmacol. 47, 261–267 (1973)
Gillespie, J. S.: The rat anococcygeus muscle and its response to nerve stimulation and to some drugs. Brit. J. Pharmacol. 45, 404–416 (1972)
Gillespie, J. S., Creed, K. E., Muir, T. C.: Electrical changes underlying excitation and inhibition in intestinal and related smooth muscle. Phil. Trans. B 265, 95–106 (1973)
Gillespie, J. S., Maxwell, J. D.: Adrenergic innervation of sphincteric and non-sphincteric smooth muscle in the rat intestine. J. Histochem. Cytochem. 19, 676–681 (1971)
Gillespie, J. S., McGrath, J. C.: The spinal origin of the motor and inhibitory innervation of the rat anococcygeus muscles. J. Physiol. (Lond.) 230, 659–672 (1973)
Gillespie, J. S., McGrath, J. C.: The response of the cat anococcygeus muscle to nerve or drug stimulation and a comparison with the rat anococcygeus. Brit. J. Pharmacol. 50, 109–118 (1974)
Henderson, R. M., Duchon, G., Daniel, E. E.: Cell contacts in duodenal smooth muscle layers. Amer. J. Physiol. 221, 564–574 (1971)
Lane, B. P., Rhodin, J.A.G.: Cellular interrelationships and electrical activity in two types of smooth muscle. J. Ultrastruct. Res. 10, 470–488 (1964)
Lever, J. D., Graham, J.D.P., Irvine, G., Chick, W. J.: The vesiculated axons in relation to arteriolar smooth muscle in the pancreas. A fine structural and quantitative study. J. Anat. (Lond.) 99, 299–313 (1965)
Merrillees, N.C.R., Burnstock, G., Holman, M. E.: Correlation of fine structure and physiology of the innervation of smooth muscle in the guinea pig vas deferens. J. Cell Biol. 19, 529–550 (1963)
Nagasawa, J., Mito, S.: Electron microscopic study on the cellular interrelationships in the smooth muscle. Tohoku J. exp. Med. 91, 277–293 (1967)
Revel, J. P., Olsen, W., Karnovsky, M. J.: A twenty-Ångstrom gap junction with hexagonal array of subunits in smooth muscle. J. Cell Biol. 35, 112A (1967)
Richardson, K. C.: The fine structure of autonomic nerve endings in smooth muscle of the rat vas deferens. J. Anat. (Lond.) 96, 427–442 (1962)
Sjöstrand, N. O.: The adrenergic innervation of the vas deferens and the accessory male genital glands. Acta physiol. scand. 65, Suppl. 257 (1965)
Taxi, J.: Contribution a l'étude des connexions des neurones moteurs du système nerveux autonome. Naturelles Zoologie 12e Série VII, 413–674 (1965)
Thoenen, H., Tranzer, J. P., Hürlimann, A., Haefely, W.: Untersuchungen zur Frage eines cholinergischen Gliedes in der postganglionären sympathischen Transmission. Helv. physiol. pharmacol. Acta 24, 229–246 (1966)
Tranzer, J. P., Thoenen, H.: Electronmicroscopic localisation of 5 hydroxytryptamine (3,4,5 trihydroxyphenylethylamine) a new “false” sympathetic transmitter. Experientia (Basel) 23, 743–745 (1967)
Uehara, Y., Burnstock, G.: Demonstration of “gap” junctions between smooth muscle cells. J. Cell Biol. 44, 215–217 (1970)
Yamauchi, A., Burnstock, G.: Post-natal development of the innervation of the mouse vas deferens. A fine structural study. J. Anat. (Lond.) 104, 17–32 (1969)
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Gillespie, J.S., Lüllmann-Rauch, R. On the ultrastructure of the rat anococcygeus muscle. Cell Tissue Res. 149, 91–104 (1974). https://doi.org/10.1007/BF00209052
- Anococcygeal muscle
- Smooth muscle
- Innervation, adrenergic