Abstract
1. Filaments were dissected from the aortic nerve of cats and impulses recorded monophasically in vivo.
2. The temporal characteristics of impulses of non-medullated fibres were compared with those of medullated fibres with conduction velocities between 4·5 and 12 m/sec. There were no obvious qualitative differences between the two types of fibres and they appeared to belong to a homogeneous sample.
3. In non-medullated fibres the rise time, fall time and absolute refractory period varied inversely with conduction velocity, the relation being similar to that in the medullated fibres. There was practically no difference between the temporal characteristics of the fastest non-medullated fibres and those of the slowest medullated fibres, a result which might throw light on the question why fibres below 1 μ in diameter are not medullated.
4. The mean blocking temperature of sixteen non-medullated fibres was 4·3° C, a value that was significantly different from the mean blocking temperature of sixteen medullated fibres (6·5° C).
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- AGOSTONI E., CHINNOCK J. E., DE DALY M. B., MURRAY J. G. Functional and histological studies of the vagus nerve and its branches to the heart, lungs and abdominal viscera in the cat. J Physiol. 1957 Jan 23;135(1):182–205. doi: 10.1113/jphysiol.1957.sp005703. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DEVANANDAN M. S. A STUDY OF THE MYELINATED FIBRES OF THE AORTIC NERVE OF CATS. J Physiol. 1964 Jun;171:361–367. doi: 10.1113/jphysiol.1964.sp007381. [DOI] [PMC free article] [PubMed] [Google Scholar]
- GASSER H. S. Unmedullated fibers originating in dorsal root ganglia. J Gen Physiol. 1950 Jul 20;33(6):651–690. doi: 10.1085/jgp.33.6.651. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HODGKIN A. L. A note on conduction velocity. J Physiol. 1954 Jul 28;125(1):221–224. doi: 10.1113/jphysiol.1954.sp005152. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HODGKIN A. L., HUXLEY A. F. A quantitative description of membrane current and its application to conduction and excitation in nerve. J Physiol. 1952 Aug;117(4):500–544. doi: 10.1113/jphysiol.1952.sp004764. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HUXLEY A. F. Ion movements during nerve activity. Ann N Y Acad Sci. 1959 Aug 28;81:221–246. doi: 10.1111/j.1749-6632.1959.tb49311.x. [DOI] [PubMed] [Google Scholar]
- Huxley A. F., Stämpfli R. Evidence for saltatory conduction in peripheral myelinated nerve fibres. J Physiol. 1949 May 15;108(3):315–339. [PMC free article] [PubMed] [Google Scholar]
- Paintal A. S. Block of conduction in mammalian myelinated nerve fibres by low temperatures. J Physiol. 1965 Sep;180(1):1–19. [PMC free article] [PubMed] [Google Scholar]
- Paintal A. S. Effects of temperature on conduction in single vagal and saphenous myelinated nerve fibres of the cat. J Physiol. 1965 Sep;180(1):20–49. [PMC free article] [PubMed] [Google Scholar]
- Paintal A. S., Riley R. L. Responses of aortic chemoreceptors. J Appl Physiol. 1966 Mar;21(2):543–548. doi: 10.1152/jappl.1966.21.2.543. [DOI] [PubMed] [Google Scholar]
- Paintal A. S. The influence of diameter of medullated nerve fibres of cats on the rising and falling phases of the spike and its recovery. J Physiol. 1966 Jun;184(4):791–811. doi: 10.1113/jphysiol.1966.sp007948. [DOI] [PMC free article] [PubMed] [Google Scholar]
- RUSHTON W. A. H. A theory of the effects of fibre size in medullated nerve. J Physiol. 1951 Sep;115(1):101–122. doi: 10.1113/jphysiol.1951.sp004655. [DOI] [PMC free article] [PubMed] [Google Scholar]
- STAMPFLI R. Saltatory conduction in nerve. Physiol Rev. 1954 Jan;34(1):101–112. doi: 10.1152/physrev.1954.34.1.101. [DOI] [PubMed] [Google Scholar]
- Vizoso A. D., Young J. Z. Internode length and fibre diameter in developing and regenerating nerves. J Anat. 1948 Apr;82(Pt 1-2):110–134.1. [PMC free article] [PubMed] [Google Scholar]