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Nicholas Mrosovsky

December 15, 2023

Nicholas Mrosovsky (3 March 1934 – 22 February 2015) was a Canadian zoologist known for his research in the fields of homeostasis, chronobiology, and sea turtle biology. He spent his whole professional career at the University of Toronto. His laboratory was notable for its seminal investigations of the influence of behavioural arousal on circadian rhythms. He was also the founder, in 1976, of Marine Turtle Newsletter. He received a Guggenheim Fellowship in 1973, and in 1993 he was elected a Fellow of the Royal Society of Canada.

Nicholas Mrosovsky
Born(1934-03-03)March 3, 1934
Romania
DiedFebruary 22, 2015(2015-02-22) (aged 80)
Toronto, Canada
EducationMagdalene College, Cambridge
University College London
SpouseSara Shettleworth
Children2
Scientific career
InstitutionsUniversity of Toronto

Early life and education edit

Mrosovsky was born in 1934 in Romania, to British parents. He was educated at Winchester College in England. He received an undergraduate degree from Magdalene College, Cambridge, and a PhD from University College London. In 1967 he joined the Department of Zoology at the University of Toronto, where he spent his entire career, with cross-appointments to the Department of Psychology and to the Department of Physiology.[1]

Work on homeostasis edit

Much of Mrosovsky's early research was concerned with the regulation of body weight, in hibernators at first and then in other animals. Together with graduate student David Sherry and colleague Jerry Hogan, he showed that lone incubating birds lose body weight throughout incubation not because of a lack of feeding opportunities but rather because it is programmed in them, the setpoint for body weight slowly decreasing until the end of the incubation period, an adaptation to minimize the time budget conflict between feeding and incubation duties.[2]

Work in chronobiology edit

Mrosovky's early work on weight regulation during hibernation led to studies on circannual rhythms.[3] With graduate student Janet Joy he found that endogenous circannual rhythms of body weight and molt in golden-mantled ground squirrels and in thirteen-lined ground squirrels could be delayed by cold temperatures in the spring,[4][5] suggesting that spring temperatures in nature can help synchronize the period of circannual rhythms in hibernators to an annual periodicity.

From these first forays into chronobiology, Mrosovsky's lab developed a productive research program on circadian rhythms, specializing on how golden hamster circadian rhythms of activity could be entrained or shifted by non-photic factors such as social interaction,[6] socio-sexual cues,[7] and novelty-induced wheel-running.[8] The latter factor was later shown to also be effective in a diurnal mammal, the European ground squirrel.[9] The phase-shifting effects of strong behavioural arousal (as confirmed by running activity) is robust and further studies from the Mrosovsky lab showed that it in fact mediates the action of other stimuli on circadian rhythms, such as the benzodiazepine triazolam[10] and pulses of darkness given on a background of constant light.[11] He also interpreted the effects of behavioural arousal in the context of possible masking (or direct effects on the output of the circadian clock rather than on the clock itself)[12] and of clock gene expression.[13]

Work on sea turtles edit

Mrosovsky's early research included the study of phototaxis, first in frogs[14][15] and then in turtles.[16][17] This led to his and his wife Sara Shettleworth’s experimental demonstration that young sea turtles, freshly emerged from their nest on a beach, use luminosity to find the sea, the sky over the sea always being brighter than the vegetation-rimmed beach edge inland.[18][19] There followed further studies on the visual system of turtle hatchlings, and on the influence of temperature on sex ratio, nest selection, and nest emergence in sea turtles.

His interest in sea turtles expanded to issues of conservation. For more than four decades he was an active member of the IUCN-SSC Marine Turtle Specialist Group.[20] He founded the quarterly periodical Marine Turtle Newsletter in 1976.[21] He did not shy away from expressing contentious opinions, such as the possibility of harvesting sea turtles in a sustainable way.[22] and a criticism of the IUCN for basing its listings of endangered species on information not publicly available.[23]

Awards edit

Publications edit

Nicholas Mrosovsky authored four books and authored or co-authored more than 200 scientific articles. He also contributed several entries to the News & Views column of the scientific journal Nature, and numerous editorials in Marine Turtle Newsletter.

Books:

  • Mrosovsky, N. (1971). Hibernation and the Hypothalamus. New York: Springer.
  • Mrosovsky, N. (1983). Conserving Sea Turtles. London: British Herpetological Society.
  • Mrosovsky, N. (1990). Rheostasis: The Physiology of Change. New York: Oxford University Press.
  • Mrosovsky, N. (2000). Sustainable Use of Hawksbill Turtles: Contemporary Issues in Conservation. Darwin: Key Centre for Tropical Wildlife Management.

Notable papers:

  • Mrosovsky, N. (1962). "Changes in multilocular brown adipose tissue in the rat following hypothermia." Nature 196: 72–73. DOI: 10.1038/196072a0
  • Mrosovsky, N. (1966). "Plasticity of reactions to light in frogs and a possible role for the pineal eye." Nature 210: 1174–1175. DOI: 10.1038/2101174a0
  • Mrosovsky, N. (1968) "Nocturnal emergence of hatchling sea turtles: control by thermal inhibition of activity." Nature 220: 1338–1339. DOI: 10.1038/2201338a0
  • Frair, W., Ackman, R.G., Mrosovsky, N. (1972) "Body temperature of Dermochelys coriacea: warm turtle from cold water." Science 177: 791–793. DOI: 10.1126/science.177.4051.791
  • Mrosovsky, N. (1977) "Hibernation and body weight in dormice: a new type of endogenous cycle." Science 196: 902–903. DOI: 10.1126/science.860123
  • Mrosovsky, N., Sherry, D.F. (1980). "Animal anorexias." Science 207: 837–842. DOI: 10.1126/science.6928327
  • Mrosovsky, N., Hopkins-Murphy, S.R., Richardson, J.L. (1984). "Sex ratio of sea turtles: seasonal changes." Science 225: 739–741. DOI: 10.1126/science.225.4663.739
  • Mrosovsky, N., Salmon, P.A. (1987). "A behavioural method for accelerating re-entrainment of rhythms to new light-dark cycles." Nature 330: 372–373. DOI: 10.1038/330372a0

References edit

  1. ^ Lakin-Thomas, P. (2015). "In memoriam: Nicholas Mrosovsky". Journal of Biological Rhythms. 30 (5): 359–363. doi:10.1177/0748730415602167. PMID 26359435. S2CID 32974966.
  2. ^ Sherry, D.; Mrosovsky, N.; Hogan, J.A. (1980). "Weight loss and anorexia during incubation in birds". Journal of Comparative and Physiological Psychology. 94: 89–98. doi:10.1037/h0077647.
  3. ^ Mrosovsky, N. (1980). "Circannual cycles in golden-mantled ground squirrels: Experiments with food deprivation and effects of temperature on periodicity". Journal of Comparative Physiology A. 136 (4): 355–360. doi:10.1007/BF00657357. S2CID 1307642.
  4. ^ Joy, J.; Mrosovsky, N. (1983). "Circannual cycles in golden-mantled ground squirrels: Lengthening of period by low temperatures in the spring phase". Journal of Comparative Physiology A. 150 (2): 233–238. doi:10.1007/BF00606373. S2CID 24380073.
  5. ^ Joy, J.; Mrosovsky, N. (1985). "Synchronization of circannual cycles: A cold spring delays the cycles of thirteen-lined ground squirrels". Journal of Comparative Physiology A. 156: 125–134. doi:10.1007/BF00610673. S2CID 24689315.
  6. ^ Mrosovsky, N. (1988). "Phase response curves for social entrainment". Journal of Comparative Physiology A. 162 (1): 35–46. doi:10.1007/BF01342701. PMID 3351785. S2CID 1805802.
  7. ^ Honrado, G.I..; Mrosovsky, N. (1989). "Arousal by sexual stimuli accelerates the re-entrainment of hamsters to phase advanced light-dark cycles". Behavioral Ecology and Sociobiology. 25: 57–63. doi:10.1007/BF00299711. S2CID 7076600.
  8. ^ Reebs, S.G..; Mrosovsky, N. (1989). "Effects of induced wheel running on the circadian activity rhythms of Syrian hamsters: Entrainment and phase response curve". Journal of Biological Rhythms. 4 (1): 39–48. doi:10.1177/074873048900400103. PMID 2519579. S2CID 888120.
  9. ^ Hut, R.A.; Mrosovsky, N.; Daan, S. (1999). "Nonphotic entrainment in a diurnal mammal, the European ground squirrel (Spermophilus citellus)". Journal of Biological Rhythms. 14 (5): 409–419. doi:10.1177/074873099129000812. PMID 10511008. S2CID 10501411.
  10. ^ Mrosovsky, N.; Salmon, P.A. (1990). "Triazolam and phase-shifting acceleration re-evaluated". Chronobiology International. 7 (1): 35–41. doi:10.3109/07420529009056952. PMID 2372850.
  11. ^ Reebs, S.G.; Lavery, R.J.; Mrosovsky, N. (1989). "Running activity mediates the phase-advancing effects of dark pulses on hamster circadian rhythms". Journal of Comparative Physiology A. 165 (6): 811–818. doi:10.1007/BF00610879. PMID 2810151. S2CID 21431397.
  12. ^ Mrosovsky, N. (1999). "Masking: history, definitions, and measurement". Chronobiology International. 16 (4): 415–429. doi:10.3109/07420529908998717. PMID 10442236.
  13. ^ Maywood, E.S.; Mrosovsky, N.; Field, M.D.; Hastings, M.H. (1999). "Rapid down-regulation of mammalian Period genes during behavioral resetting of the circadian clock". Proceedings of the National Academy of Sciences. 96 (26): 15211–15216. doi:10.1073/pnas.96.26.15211. PMC 24799. PMID 10611364.
  14. ^ Boycott, B.B.; Mrosovsky, N.; Muntz, W.R. (1964). "Black and white preferences in the frog, Rana temporaria, and other anura". Journal of Experimental Biology. 41 (4): 865–877. doi:10.1242/jeb.41.4.865. PMID 14239914.
  15. ^ Mrosovsky, N.; Tress, K.H. (1966). "Plasticity of reactions to light in frogs and a possible role for the pineal eye". Nature. 210 (5041): 1174–1175. doi:10.1038/2101174a0. PMID 5964185. S2CID 4277069.
  16. ^ Mrosovsky, N.; Boycott, B.B. (1966). "Intra- and interspecific differences in phototactic behaviour of freshwater turtles". Behaviour. 26 (3–4): 215–227. doi:10.1163/156853965x00192. PMID 5933271.
  17. ^ Mrosovsky, N.; Carr, A. (1967). "Preference for light of short wavelengths in hatchling green sea turtles, Chelonia mydas, tested on their natural nesting beaches". Behaviour. 28 (3–4): 217–231. doi:10.1163/156853967x00019. PMID 6038298.
  18. ^ Mrosovsky, N.; Shettleworth, S.J. (1968). "Wavelength preferences and brightness cues in the water finding behaviour of sea turtles". Behaviour. 32 (4): 211–217. doi:10.1163/156853968x00216. PMID 5717260.
  19. ^ Mrosovsky, N.; Shettleworth, S.J. (1974). "Further studies of the sea-finding mechanism in green turtle hatchlings". Behaviour. 51 (3–4): 195–208. doi:10.1163/156853974x00192. PMID 4447586.
  20. ^ Godfrey, M.H. (2016). "In memoriam: Nicholas Mrosovsky (1934-2015)". Marine Turtle Newsletter. 148: 16.
  21. ^ "About the Marine Turtle Newsletter".
  22. ^ Mrosovsky, N. (1883). Conserving Sea Turtles. London: British Herpetological Society. ISBN 0950737119.
  23. ^ Mrosovsky, N. (1997). "IUCN's credibility critically endangered". Nature. 389 (6650): 436. doi:10.1038/38873. S2CID 4389685.

December 15, 2023
nicholas, mrosovsky, march, 1934, february, 2015, canadian, zoologist, known, research, fields, homeostasis, chronobiology, turtle, biology, spent, whole, professional, career, university, toronto, laboratory, notable, seminal, investigations, influence, behav. Nicholas Mrosovsky 3 March 1934 22 February 2015 was a Canadian zoologist known for his research in the fields of homeostasis chronobiology and sea turtle biology He spent his whole professional career at the University of Toronto His laboratory was notable for its seminal investigations of the influence of behavioural arousal on circadian rhythms He was also the founder in 1976 of Marine Turtle Newsletter He received a Guggenheim Fellowship in 1973 and in 1993 he was elected a Fellow of the Royal Society of Canada Nicholas MrosovskyBorn 1934 03 03 March 3 1934RomaniaDiedFebruary 22 2015 2015 02 22 aged 80 Toronto CanadaEducationMagdalene College CambridgeUniversity College LondonSpouseSara ShettleworthChildren2Scientific careerInstitutionsUniversity of Toronto Contents 1 Early life and education 2 Work on homeostasis 3 Work in chronobiology 4 Work on sea turtles 5 Awards 6 Publications 7 ReferencesEarly life and education editMrosovsky was born in 1934 in Romania to British parents He was educated at Winchester College in England He received an undergraduate degree from Magdalene College Cambridge and a PhD from University College London In 1967 he joined the Department of Zoology at the University of Toronto where he spent his entire career with cross appointments to the Department of Psychology and to the Department of Physiology 1 Work on homeostasis editMuch of Mrosovsky s early research was concerned with the regulation of body weight in hibernators at first and then in other animals Together with graduate student David Sherry and colleague Jerry Hogan he showed that lone incubating birds lose body weight throughout incubation not because of a lack of feeding opportunities but rather because it is programmed in them the setpoint for body weight slowly decreasing until the end of the incubation period an adaptation to minimize the time budget conflict between feeding and incubation duties 2 Work in chronobiology editMrosovky s early work on weight regulation during hibernation led to studies on circannual rhythms 3 With graduate student Janet Joy he found that endogenous circannual rhythms of body weight and molt in golden mantled ground squirrels and in thirteen lined ground squirrels could be delayed by cold temperatures in the spring 4 5 suggesting that spring temperatures in nature can help synchronize the period of circannual rhythms in hibernators to an annual periodicity From these first forays into chronobiology Mrosovsky s lab developed a productive research program on circadian rhythms specializing on how golden hamster circadian rhythms of activity could be entrained or shifted by non photic factors such as social interaction 6 socio sexual cues 7 and novelty induced wheel running 8 The latter factor was later shown to also be effective in a diurnal mammal the European ground squirrel 9 The phase shifting effects of strong behavioural arousal as confirmed by running activity is robust and further studies from the Mrosovsky lab showed that it in fact mediates the action of other stimuli on circadian rhythms such as the benzodiazepine triazolam 10 and pulses of darkness given on a background of constant light 11 He also interpreted the effects of behavioural arousal in the context of possible masking or direct effects on the output of the circadian clock rather than on the clock itself 12 and of clock gene expression 13 Work on sea turtles editMrosovsky s early research included the study of phototaxis first in frogs 14 15 and then in turtles 16 17 This led to his and his wife Sara Shettleworth s experimental demonstration that young sea turtles freshly emerged from their nest on a beach use luminosity to find the sea the sky over the sea always being brighter than the vegetation rimmed beach edge inland 18 19 There followed further studies on the visual system of turtle hatchlings and on the influence of temperature on sex ratio nest selection and nest emergence in sea turtles His interest in sea turtles expanded to issues of conservation For more than four decades he was an active member of the IUCN SSC Marine Turtle Specialist Group 20 He founded the quarterly periodical Marine Turtle Newsletter in 1976 21 He did not shy away from expressing contentious opinions such as the possibility of harvesting sea turtles in a sustainable way 22 and a criticism of the IUCN for basing its listings of endangered species on information not publicly available 23 Awards editGuggenheim Fellowship 1973 Fellow Royal Society of Canada 1993 Canada Council Killam Research Fellowship 1994 Lifetime Achievement Award International Sea Turtle Society 2008 Publications editNicholas Mrosovsky authored four books and authored or co authored more than 200 scientific articles He also contributed several entries to the News amp Views column of the scientific journal Nature and numerous editorials in Marine Turtle Newsletter Books Mrosovsky N 1971 Hibernation and the Hypothalamus New York Springer Mrosovsky N 1983 Conserving Sea Turtles London British Herpetological Society Mrosovsky N 1990 Rheostasis The Physiology of Change New York Oxford University Press Mrosovsky N 2000 Sustainable Use of Hawksbill Turtles Contemporary Issues in Conservation Darwin Key Centre for Tropical Wildlife Management Notable papers Mrosovsky N 1962 Changes in multilocular brown adipose tissue in the rat following hypothermia Nature 196 72 73 DOI 10 1038 196072a0 Mrosovsky N 1966 Plasticity of reactions to light in frogs and a possible role for the pineal eye Nature 210 1174 1175 DOI 10 1038 2101174a0 Mrosovsky N 1968 Nocturnal emergence of hatchling sea turtles control by thermal inhibition of activity Nature 220 1338 1339 DOI 10 1038 2201338a0 Frair W Ackman R G Mrosovsky N 1972 Body temperature of Dermochelys coriacea warm turtle from cold water Science 177 791 793 DOI 10 1126 science 177 4051 791 Mrosovsky N 1977 Hibernation and body weight in dormice a new type of endogenous cycle Science 196 902 903 DOI 10 1126 science 860123 Mrosovsky N Sherry D F 1980 Animal anorexias Science 207 837 842 DOI 10 1126 science 6928327 Mrosovsky N Hopkins Murphy S R Richardson J L 1984 Sex ratio of sea turtles seasonal changes Science 225 739 741 DOI 10 1126 science 225 4663 739 Mrosovsky N Salmon P A 1987 A behavioural method for accelerating re entrainment of rhythms to new light dark cycles Nature 330 372 373 DOI 10 1038 330372a0References edit Lakin Thomas P 2015 In memoriam Nicholas Mrosovsky Journal of Biological Rhythms 30 5 359 363 doi 10 1177 0748730415602167 PMID 26359435 S2CID 32974966 Sherry D Mrosovsky N Hogan J A 1980 Weight loss and anorexia during incubation in birds Journal of Comparative and Physiological Psychology 94 89 98 doi 10 1037 h0077647 Mrosovsky N 1980 Circannual cycles in golden mantled ground squirrels Experiments with food deprivation and effects of temperature on periodicity Journal of Comparative Physiology A 136 4 355 360 doi 10 1007 BF00657357 S2CID 1307642 Joy J Mrosovsky N 1983 Circannual cycles in golden mantled ground squirrels Lengthening of period by low temperatures in the spring phase Journal of Comparative Physiology A 150 2 233 238 doi 10 1007 BF00606373 S2CID 24380073 Joy J Mrosovsky N 1985 Synchronization of circannual cycles A cold spring delays the cycles of thirteen lined ground squirrels Journal of Comparative Physiology A 156 125 134 doi 10 1007 BF00610673 S2CID 24689315 Mrosovsky N 1988 Phase response curves for social entrainment Journal of Comparative Physiology A 162 1 35 46 doi 10 1007 BF01342701 PMID 3351785 S2CID 1805802 Honrado G I Mrosovsky N 1989 Arousal by sexual stimuli accelerates the re entrainment of hamsters to phase advanced light dark cycles Behavioral Ecology and Sociobiology 25 57 63 doi 10 1007 BF00299711 S2CID 7076600 Reebs S G Mrosovsky N 1989 Effects of induced wheel running on the circadian activity rhythms of Syrian hamsters Entrainment and phase response curve Journal of Biological Rhythms 4 1 39 48 doi 10 1177 074873048900400103 PMID 2519579 S2CID 888120 Hut R A Mrosovsky N Daan S 1999 Nonphotic entrainment in a diurnal mammal the European ground squirrel Spermophilus citellus Journal of Biological Rhythms 14 5 409 419 doi 10 1177 074873099129000812 PMID 10511008 S2CID 10501411 Mrosovsky N Salmon P A 1990 Triazolam and phase shifting acceleration re evaluated Chronobiology International 7 1 35 41 doi 10 3109 07420529009056952 PMID 2372850 Reebs S G Lavery R J Mrosovsky N 1989 Running activity mediates the phase advancing effects of dark pulses on hamster circadian rhythms Journal of Comparative Physiology A 165 6 811 818 doi 10 1007 BF00610879 PMID 2810151 S2CID 21431397 Mrosovsky N 1999 Masking history definitions and measurement Chronobiology International 16 4 415 429 doi 10 3109 07420529908998717 PMID 10442236 Maywood E S Mrosovsky N Field M D Hastings M H 1999 Rapid down regulation of mammalian Period genes during behavioral resetting of the circadian clock Proceedings of the National Academy of Sciences 96 26 15211 15216 doi 10 1073 pnas 96 26 15211 PMC 24799 PMID 10611364 Boycott B B Mrosovsky N Muntz W R 1964 Black and white preferences in the frog Rana temporaria and other anura Journal of Experimental Biology 41 4 865 877 doi 10 1242 jeb 41 4 865 PMID 14239914 Mrosovsky N Tress K H 1966 Plasticity of reactions to light in frogs and a possible role for the pineal eye Nature 210 5041 1174 1175 doi 10 1038 2101174a0 PMID 5964185 S2CID 4277069 Mrosovsky N Boycott B B 1966 Intra and interspecific differences in phototactic behaviour of freshwater turtles Behaviour 26 3 4 215 227 doi 10 1163 156853965x00192 PMID 5933271 Mrosovsky N Carr A 1967 Preference for light of short wavelengths in hatchling green sea turtles Chelonia mydas tested on their natural nesting beaches Behaviour 28 3 4 217 231 doi 10 1163 156853967x00019 PMID 6038298 Mrosovsky N Shettleworth S J 1968 Wavelength preferences and brightness cues in the water finding behaviour of sea turtles Behaviour 32 4 211 217 doi 10 1163 156853968x00216 PMID 5717260 Mrosovsky N Shettleworth S J 1974 Further studies of the sea finding mechanism in green turtle hatchlings Behaviour 51 3 4 195 208 doi 10 1163 156853974x00192 PMID 4447586 Godfrey M H 2016 In memoriam Nicholas Mrosovsky 1934 2015 Marine Turtle Newsletter 148 16 About the Marine Turtle Newsletter Mrosovsky N 1883 Conserving Sea Turtles London British Herpetological Society ISBN 0950737119 Mrosovsky N 1997 IUCN s credibility critically endangered Nature 389 6650 436 doi 10 1038 38873 S2CID 4389685 Retrieved from https en wikipedia org w index php title Nicholas Mrosovsky amp oldid 1184103841, wikipedia, wiki, book, books, library,

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