The action of nicotin on the ciliary ganglion and on the endings of the third cranial nerve / by J. N. Langley and H. K. Anderson.

  • Langley, J. N. (John Newport), 1852-1925.
Date:
[1892]
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Licence: Public Domain Mark

Credit: The action of nicotin on the ciliary ganglion and on the endings of the third cranial nerve / by J. N. Langley and H. K. Anderson. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    amount will of course vary, according to the preparation of curari used. Curari in large amount paralyses the cells of the ciliary ganglion. The other effects of the 3rd nerve cease, not because of a paralysis of motor nerve-endings, but because of the paralysing action of nicotin upon the nerve-cells of the ciliary ganglion. For stimulation of the short ciliary nerves still causes contraction of the sphincter iridis and of the ciliary muscle even after 100 mgrs. of nicotin have been injected (cp. Exp. I). The short ciliaries lie on the optic nerve at its entrance into the eye, and we have usually stimulated them at this spot without separating them from the optic. After section of the cervical sympa- thetic or after extirpation of the eye, stimulation of the optic nerve with the short ciliaries still causes a ready contraction of the pupil. We have in one or two cases in the cat isolated the short ciliaries and stimulated them separately as in the following experiment:— Experiment I. Cat. Chloroform. Trachea connected with a bottle of a. c. e. mixture. The ciliary ganglion was exposed by the method given by Jegorow \ the 3rd nerve and the short ciliaries isolated for a short distance on either side of the ganglion. Stimulation of the 3rd nerve caused prompt constriction of the pupil. 1.20. 5 C.C. of a 1 p.c. solution of nicotin (=50 mgrs.) injected into the jugular vein. 1.28. Stimulate 3rd nerve centrally of ganglion—no effect. Stimulate ciliary ganglion—constriction of pupil, but less than before injection. Stimulate short ciliaries—prompt constriction of pupil. 1.34. Repeat stimulation—same result. 1,37. 5 c.c. of a 1 p.c. solution of nicotin injected into the jugular. 1.39. Repeat stimulations—same result. Cut off the cornea, and cut through the iris; there was profuse bleeding, showing that the circulation had not been interrupted by the operation. Dissect out 3rd nerve, ganglion and short ciliaries on the opposite sidf\ Pass a needle through the edge of the cornea so that its point rests on the anterior surface of the lens. Stimulate 3rd nerve centrally of ganglion—no effect Stimulate short ciliaries—movement of needle showing protrusion of lens and contraction of the ciliary muscle. ^ Jegorow. Arch. f. Anat. u. Physiol. (Physiol. Abth.) p. 149, 1886. 2 The diminished effect of stimulating the ciliary ganglion was probably due to the presence of small accessory ganglia on the short ciliaries.