Abstract
This paper focuses on how the electric field from the prey of the platypus is detected with respect to the questions of threshold determination and how the platypus might localize its prey. A new behaviour in response to electrical stimuli below the thresholds previously reported is presented. The platypus shows a voluntary exploratory behaviour that results from a temporal integration of a number of consecutive stimulus pulses. A theoretical analysis is given, which includes the threshold dependence on the number of receptors and temporal integration of consecutive stimuli pulses, the close relationships between electrical field decay across the bill, electroreceptive thresholds and directionality of the platypus bill acting as an antenna. It is shown that a lobe shape, similar to that which has been measured, can be obtained by combining responses in a specific way from receptors sensing the electric field decay across the bill. Two possible methods for such combinations are discussed and analysed with respect to measurements and observed behaviour of the platypus. A number of factors are described which need to be considered when electroreceptive thresholds are to be determined. It is shown that some information about the distance to the source is theoretically available from the pattern of field decay across the platypus's bill. The paper includes a comparative analysis of radar target tracking and platypus prey localization.
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Selected References
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- Andres K. H., von Düring M. Comparative anatomy of vertebrate electroreceptors. Prog Brain Res. 1988;74:113–131. doi: 10.1016/s0079-6123(08)63006-x. [DOI] [PubMed] [Google Scholar]
- Gregory J. E., Iggo A., McIntyre A. K., Proske U. Receptors in the bill of the platypus. J Physiol. 1988 Jun;400:349–366. doi: 10.1113/jphysiol.1988.sp017124. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kalmijn A. J. Electric and magnetic field detection in elasmobranch fishes. Science. 1982 Nov 26;218(4575):916–918. doi: 10.1126/science.7134985. [DOI] [PubMed] [Google Scholar]
- Krubitzer L., Manger P., Pettigrew J., Calford M. Organization of somatosensory cortex in monotremes: in search of the prototypical plan. J Comp Neurol. 1995 Jan 9;351(2):261–306. doi: 10.1002/cne.903510206. [DOI] [PubMed] [Google Scholar]
- Manger P. R., Pettigrew J. D., Keast J. R., Bauer A. Nerve terminals of mucous gland electroreceptors in the platypus (Ornithorhynchus anatinus). Proc Biol Sci. 1995 Apr 22;260(1357):13–19. doi: 10.1098/rspb.1995.0053. [DOI] [PubMed] [Google Scholar]
- Manger P. R., Pettigrew J. D. Ultrastructure, number, distribution and innervation of electroreceptors and mechanoreceptors in the bill skin of the platypus, Ornithorhynchus anatinus. Brain Behav Evol. 1996;48(1):27–54. doi: 10.1159/000113185. [DOI] [PubMed] [Google Scholar]
- Scheich H., Langner G., Tidemann C., Coles R. B., Guppy A. Electroreception and electrolocation in platypus. 1986 Jan 30-Feb 5Nature. 319(6052):401–402. doi: 10.1038/319401a0. [DOI] [PubMed] [Google Scholar]