Summary
We have tested the hypothesis that the avian pineal hormone, melatonin, which is produced in and secreted from the pineal body in a circadian temporal pattern is a chemical mediator which drives overt circadian functions. Pinealectomized European starlings (Sturnus vulgaris) kept in continuous dim light, received intramuscular injections of melatonin at the same time each day for several weeks. Control birds received only sesame oil injections. In 21 out of 22 birds, melatonin treatment resulted in the synchronization of locomotor activity with the 24 h injection rhythm. In contrast, activity of only one out of 10 control birds became synchronized with the daily control injections. These results are consistent with the hypothesis that the endogenous circadian rhythm of melatonin concentration provides an internal synchronizing agent, acting directly on other circadian oscillators. Alternatively, it seems possible that the exogenous rhythm exerts its effect indirectly by modifying the sleep-wake cycle.
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Antón-Tay, F., Diaz, J.L., Fernandez-Guardiola, A.: On the effects of melatonin upon human brain. Its possible therapeutic implications. Life Sciences10, 841–850 (1971)
Binkley, S.: Pineal gland biorhythms: N-acetyltransferase in chickens and rats. Fed. Proc.35, 2347–2352 (1976)
Binkley, S., Kluth, E., Menaker, M.: Pineal function in sparrows: circadian rhythms and body temperature. Science174, 311–314 (1971)
Binkley, S.A.: Pineal and melatonin: Circadian rhythms and body temperature of sparrows. In: Chronobiology (eds. L.E. Scheving, F. Halberg, J.E. Pauls), pp. 582–585. Stuttgart: Thieme 1974
Byrne, J.E.: Locomotor activity responses in juvenile sokeye salmon,Oncorhynchus nerka, to melatonin and serotonin. Can. J. Zool.48, 1425–1427 (1970)
Daan, S.: Light intensity and the timing of daily activity of finches (Fringillidae). Ibis118, 223–236 (1976)
Gaston, S., Menaker, M.: Pineal function: The biological clock in the sparrow? Science160, 1125–1127 (1968)
Gwinner, E.: Testosterone induces “splitting” of circadian locomotor activity rhythms in birds. Science185, 72–74 (1974)
Gwinner, E.: Role of the pineal in the control of circadian and circannual rhythms in European starlings. Proc. First Internat. Symp. Avian Endocrinology, 28–29 (1977)
Gwinner, E.: Effects of pinealectomy on circadian locomotor activity rhythms in European starlings,Sturnus vulgaris. J. comp. Physiol.126, 123–129 (1978)
Hendel, R.C., Turek, F.W.: Suppression of locomotor activity in sparrows by treatment with melatonin. Physiology and Behavior, in press (1978)
Hishikawa, Y., Cramer, H., Kuhlo, W.: Natural and melatonin-induced sleep in young chickens—a behavioral and electrographic study. Exp. Brain Res.7, 84–94 (1969)
Hoffmann, K.: Splitting of the circadian rhythm as a function of light intensity. In: Biochronometry (ed. M. Menaker), pp. 134–148. Washington: National Academy of Sciences 1971
Marczynsk, T.J., Yamaguchi, N., Ling, G.M., Grodzinska, L.: Sleep induced by the administration of melatonin (5-Methoxy-N-acetyltryptamine) to the hypothalamus in unrestrained cats. Experientia20, 435–437 (1964)
Menaker, M., Zimmerman, N.: Role of the pineal in the circadian system of birds. Am. Zool.16, 45–55 (1976)
Pang, S.F., Ralph, C.L., Reilly, D.P.: Melatonin in the chicken brain: its origin, diurnal variation, and regional distribution. Gen. Comp. Endocrinol.22, 499–506 (1974)
Pelham, R.W.: A serum melatonin rhythm in chickens and its abolition by pinealectomy. Endocrinology96, 543–546 (1975)
Pelham, R.W., Ralph, C.L.: Diurnal rhythm of serum melatonin in chicken: abolition by pinealectomy. Physiologist15, 236 (1972)
Pittendrigh, C.S., Daan, S.: A functional analysis of circadian pacemakers in nocturnal rodents. V. Pacemaker structure. A clock for all seasons. J. comp. Physiol.106, 333–355 (1976)
Ralph, C.L.: Correlations of melatonin content in pineal gland, blood and brain of some birds and mammals. Am. Zool.16, 35–43 (1976)
Ralph, C.L., Pelham, R.W., MacBride, S.E., Reilly, D.P.: Persistent rhythms of pineal and serum melatonin in cockerels in continuous darkness. J. Endocrinol.63, 319–324 (1974)
Reiss, M., Davis, R.H., Sideman, M.P., Plichta, E.S.: Pineal gland and spontaneous activity of rats. J. Endocrinol.28, 127–128 (1963)
Rutledge, J.T., Angle, M.J.: Persistence of circadian activity rhythms in pinealectomized European starlings (Sturnus vulgaris). J. exp. Zool.202, 333–338 (1977)
Turek, F.W., McMillan, J.P., Menaker, M.: Melatonin: effects on the circadian locomotor rhythm of sparrows. Science194, 1441–1443 (1976)
Wong, R., Whiteside, C.B.C.: The effect of melatonin on the wheel-running activity of rats deprived of food. J. Endocrinol.40, 383–384 (1968)
Zimmerman, N.: Organization within the circadian system of the house sparrow: hormonal coupling and the location of a circadian oscillator. Ph. D. Thesis, University of Texas (1976)
Zimmerman, N., Menaker, M.: Neural connections of sparrow pineal: role in circadian control of activity. Science190, 477–479 (1975)
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Dedicated to Professor Colin S. Pittendrigh on the occasion of his 60th birthday
This work was supported by the Deutsche Forschungsgemeinshaft. (SPP Biologie der Zeitmessung). We are grateful to Prof. A. Oksche for his help in evaluating the histological slides of brains from pinealectomized starlings. Prof. J. Aschoff, John Dittami, Prof. D.S. Farner and Dr. K. Hoffmann gave valuable comments on the manuscript.
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Gwinner, E., Benzinger, I. Synchronization of a circadian rhythm in pinealectomized European starlings by daily injections of melatonin. J. Comp. Physiol. 127, 209–213 (1978). https://doi.org/10.1007/BF01350111
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DOI: https://doi.org/10.1007/BF01350111