Abstract
The planarian ocellar potential (OP), an action potential evoked from the planarian ocellus by a light flash, was recorded with microelectrodes. OP amplitude, latency, and peak delay varied as a function of stimulus intensity and state of adaptation in a manner similar to the responses of other photoreceptors. Changes in the OP that occurred with different directions of incident light are described and attributed to screening effects of the ocellar pigment cells. The temperature coefficient (Q 10) of OP latency was 1.5; latency decreased continuously as temperature was increased to destructive levels. The energy of activation of the rate of OP formation was calculated to approximate 10 kcal. These findings suggest dependence of OP latency on ionic diffusion and of OP formation on a biocatalytic process.
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Selected References
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- BEHRENS M. E. The electrical response of the planarian photoreceptor. Comp Biochem Physiol. 1962 Feb;5:129–138. doi: 10.1016/0010-406x(62)90125-1. [DOI] [PubMed] [Google Scholar]
- Borsellino A., Fuortes M. G., Smith T. G. Visual responses in Limulus. Cold Spring Harb Symp Quant Biol. 1965;30:429–443. doi: 10.1101/sqb.1965.030.01.042. [DOI] [PubMed] [Google Scholar]
- EGUCHI E., NAKA K. I., KUWABARA M. The development of the rhabdom and the appearance of the electrical response in the insect eye. J Gen Physiol. 1962 Sep;46:143–157. doi: 10.1085/jgp.46.1.143. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eakin R. M. Evolution of photoreceptors. Cold Spring Harb Symp Quant Biol. 1965;30:363–370. doi: 10.1101/sqb.1965.030.01.036. [DOI] [PubMed] [Google Scholar]
- HARTLINE H. K., WAGNER H. G., MACNICHOL E. F., Jr The peripheral origin of nervous activity in the visual system. Cold Spring Harb Symp Quant Biol. 1952;17:125–141. doi: 10.1101/sqb.1952.017.01.013. [DOI] [PubMed] [Google Scholar]
- MACRAE E. K. OBSERVATIONS ON THE FINE STRUCTURE OF PHOTORECEPTOR CELLS IN THE PLANARIAN DUGESIA TIGRINA. J Ultrastruct Res. 1964 Apr;10:334–349. doi: 10.1016/s0022-5320(64)80013-7. [DOI] [PubMed] [Google Scholar]
- VANDEVENTER J. M., RATNER S. C. VARIABLES AFFECTING THE FREQUENCY OF RESPONSE OF PLANARIA TO LIGHT. J Comp Physiol Psychol. 1964 Jun;57:407–411. doi: 10.1037/h0042776. [DOI] [PubMed] [Google Scholar]
- WOLKEN J. J. Studies of photoreceptor structures. Ann N Y Acad Sci. 1959 Nov 12;74(2):164–181. doi: 10.1111/j.1749-6632.1958.tb39542.x. [DOI] [PubMed] [Google Scholar]
- WULFF V. J., FRY W. J., LINDE F. A. Retinal action potential; theory and experimental results for grasshopper eyes. J Cell Physiol. 1955 Apr;45(2):247–263. doi: 10.1002/jcp.1030450207. [DOI] [PubMed] [Google Scholar]
- Waterman T. H., Horch K. W. Mechanism of polarized light perception. Science. 1966 Oct 28;154(3748):467–475. doi: 10.1126/science.154.3748.467. [DOI] [PubMed] [Google Scholar]