Abstract
Nervous activity has been recorded from the unopened eye of decerebrate cats. Recordings were made with metal electrodes or with small micropipettes from ganglion cells or nerve fibers. Continuous maintained discharges were seen in all ganglion cells during steady illumination of their receptive fields, as well as in complete darkness. Possible artefacts, such as electrode pressure, abnormal circulation, anesthetic, and several other factors have been excluded as the source of the maintained discharge. Visual stimuli are therefore transmitted by modulating the ever present background activity. Discharge frequencies were measured following changes of retinal illumination. No consistent patterns of frequency change were found. The maintained discharge frequency may be permanently increased or decreased, or may remain practically unchanged by altering the steady level of illumination. In addition, there were often transient frequency changes during the first 5 to 10 minutes after changing illumination, before a final steady rate was established. A statistical analysis of the impulse intervals of the maintained discharge showed: (a) the intervals were distributed according to the gamma distribution (Pearson's type III), (b) the first serial correlation coefficient of the intervals was between –0.10 and –0.24, with a mean value of –0.17, which is significantly different from zero, (c) the higher order serial correlation coefficients were not significantly different from zero. Thus the firing probability at any time depends on the times of occurrence of the two preceding impulses only, and in such a way as to indicate that each impulse is followed by a transient depression of excitability that outlasts the following impulse. The possible sites at which spontaneous or maintained activity may originate in the retina are discussed.
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Selected References
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- Adrian E. D. Synchronized reactions in the optic ganglion of dytiscus. J Physiol. 1937 Oct 18;91(1):66–89. doi: 10.1113/jphysiol.1937.sp003545. [DOI] [PMC free article] [PubMed] [Google Scholar]
- BARLOW H. B. Retinal noise and absolute threshold. J Opt Soc Am. 1956 Aug;46(8):634–639. doi: 10.1364/josa.46.000634. [DOI] [PubMed] [Google Scholar]
- BREMER F. Considérations sur l'origine et la nature des ondes cérébrales. Electroencephalogr Clin Neurophysiol. 1949 May;1(2):177–193. [PubMed] [Google Scholar]
- BULLOCK T. H., DIECKE F. P. Properties of an infra-red receptor. J Physiol. 1956 Oct 29;134(1):47–87. doi: 10.1113/jphysiol.1956.sp005624. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cohen M. J. The function of receptors in the statocyst of the lobster Homarus americanus. J Physiol. 1955 Oct 28;130(1):9–34. doi: 10.1113/jphysiol.1955.sp005389. [DOI] [PMC free article] [PubMed] [Google Scholar]
- GREGORY R. L., CANE V. A statistical information theory of visual thresholds. Nature. 1955 Dec 31;176(4496):1272–1272. doi: 10.1038/1761272a0. [DOI] [PubMed] [Google Scholar]
- HAGIWARA S. Analysis of interval fluctuation of the sensory nerve impulse. Jpn J Physiol. 1954 Sep 1;4(3):234–240. doi: 10.2170/jjphysiol.4.234. [DOI] [PubMed] [Google Scholar]
- KATZ B. Action potentials from a sensory nerve ending. J Physiol. 1950 Oct 16;111(3-4):248–260. doi: 10.1113/jphysiol.1950.sp004478. [DOI] [PMC free article] [PubMed] [Google Scholar]
- TALBOT S. A., KUFFLER S. W. A multibeam ophthalmoscope for the study of retinal physiology. J Opt Soc Am. 1952 Dec;42(12):931–936. doi: 10.1364/josa.42.000931. [DOI] [PubMed] [Google Scholar]
- TASAKI I., DAVIS H. Electric responses of individual nerve elements in cochlear nucleus to sound stimulation (guinea pig). J Neurophysiol. 1955 Mar;18(2):151–158. doi: 10.1152/jn.1955.18.2.151. [DOI] [PubMed] [Google Scholar]
- ZOTTERMAN Y. Special senses: thermal receptors. Annu Rev Physiol. 1953;15:357–372. doi: 10.1146/annurev.ph.15.030153.002041. [DOI] [PubMed] [Google Scholar]