Om personen

Research Interest

My research integrates neuroscience, endocrinology, physiology, development, general biology of fish and environment. The aim of this research is to evaluate environmental impacts on the fish brain and endocrine systems with emphasis on important commercial, enhancement and wild fish populations (e.g. salmon and cod). This knowledge will be used to develop molecular tools to monitor and evaluate brain structure and function in a wide range of situations in fish.

The purpose is to identify environmental factors that regulate or disrupt brain development and/or function in order to improve rearing strategies designed specifically for aquaculture or enhancement and restoration of wild populations. Why? Disruption of proper brain development can lead to altered endocrine and physiological development that will have consequences on growth, survival and life history trajectory.

Research topics

  • Molecular and functional relationships between environmental stress, neural plasticity, and learning and memory behaviours in salmon
  • Environmental impacts on fish brain development and function
  • Midlife neural plasticity in salmon: neural and endocrine mechanisms underlying the initiation, regulation and disruption of salmon parr-smolt transformation
  • Mechanisms of thyroid hormone interaction with neuroendocrine development during critical periods
  • Endocrine regulation of osmoregulatory system development in the gill during smoltification
  • Environmental regulation of thyroid hormones
  • Distribution and function of non-visual photoreceptive opsins in the brain
  • Neuroendocrine control of appetite in fish
  • Rapid forced natural selection: Comparison of anadromous (Vosso) and landlocked (Bleke) Atlantic salmon development
  • Impact of acid/Al in salmon brain, endocrine, physiological development
Other research
  • Fatty acids and the development of diabetes and assessment of cardiovascular risk factors in Alaska Eskimos


We use a few salmon models designed to evaluate environmental and genetic parameters, and to better understand life history strategies. In the lab, we employ a wide variety of techniques to help answer our questions. Distributions in tissues are primarily studied by immunocytochemistry (ICC), in situ hybridization (ISH), neural tract tracing, as well as classical staining techniques and analysed microscopic imaging with light, fluorescence and confocal-laser scanning microscopy. Quantification in tissues of genes, proteins and neurotransmitters are analysed by qPCR, Western blots and/or ELISAs, and HPLC, respectively. Circulating hormone levels are measured either by ELISAs or RIAs. Physiological parameters e.g. gill NKA activity and circulating chloride levels are also measured.


  • NFR 233870- SalmoFutura:Welfare of Atlantic salmon postsmolts in closed-containment production systems, using a function-based approach. Partner, 2014-2016.
  • NFR-FORNY2020, SalmonProbe: en ny og innovative metode for å angi smoltstatus (2014-15).
  • NFR-FRIMEDBIO, The smolt brain model: Unraveling nature´s regulation of neural plasticity. PI, 2013-2016.
  • NFR/NSF GROW- Uncovering the role of the melanocortin system in salmon smoltification. Partner, 2014.
  • EU, FP7-KBBE, 265957, ‘COPEWELL-A new integrative framework for the study of fish welfare based on the concepts of allostasis, appraisal and coping styles’, Co-PI, 2011-2015.
  • NFR 217502- Optimalisert Postsmolt: et paradigmeskifte for norsk lakseindustri (OPP), Partner 2012-2016

Selected publications:

1.       Manuel R, M Gorissen, J Zethof, LOE Ebbesson, H Vis, G Flik and R Bos (2014) Unpredictable chronic stress decreases inhibitory avoidance learning in Tuebingen Long-Fin zebrafish (Danio rerio Hamilton): stronger effects in the resting phase than in the active phase. Journal of Experimental Biology, DOI: 10.1242/jeb.109736

2.       Handeland SO, AK Imsland, TO Nilsen, LOE Ebbesson, CD Hosfeld, C Pedrosa, H Toften and SO Stefansson (2014) Osmoregulation in Atlantic salmon Salmo salar smolts transferred to seawater at different temperatures. Journal of Fish Biology DOI: 10.1111/jfb.12481

3.       Eilertsen M, Ø Drivenes, RB Edvardsen, CA Bradley, LOE Ebbesson, and JV Helvik (2014) The exorhodopsin and melanopsin systems in the pineal complex and brain at early developmental stages of Atlantic halibut (Hippoglossus hippoglossus) Journal of Comparative Neurology DOI:10.1002/cne.23652

4.       Lund I, E Höglund, LOE Ebbesson, PV Skov (2014) Dietary LC-PUFA deficiency early in ontogeny induces behavioural changes in pike perch (Sander lucioperca) larvae and fry. Aquaculture DOI: 10.1016/j.aquaculture.2014.05.039

5.       Braithwaite VA and LOE Ebbesson (2014) Pain and stress responses in farmed fish. In: Animal Welfare: focusing on the future. OIE Scientific and Technical Review, 33: 245-253.

6.       Nilsen TO, LOE Ebbesson, SO Handeland,  F Kroglund, B Finstad, AR  Angotzi, SO Stefansson (2013) Atlantic salmon (Salmo salar L.) smolts require more than two weeks to recover from acidic water and aluminium exposure. Aquatic Toxicology 142-143:33-44

7.       Salvanes AGV, O Moberg, LOE Ebbesson, TO Nilsen, KH Jensen, VA Braithwaite (2013). Environmental enrichment promotes neural plasticity and cognative behaviour in fish. Proceedings of the Royal Society B doi:10.1098/rspb.2013.1331

8.       Grassie C, VA Braithwaite, J Nilsson, TO Nilsen, H-C Teien, SO Handeland, SO Stefansson, V Tronci, M Gorissen, G Flik, LOE Ebbesson (2013) Aluminum exposure impacts brain plasticity and behavior in Atlantic salmon (Salmo salar). Journal of Experimental Biology, doi:10.1242/jeb.083550

9.       Handeland S, AK Imsland, LOE Ebbesson, TO Nilsen, CD Hosfeld, HCh Teien, SO Stefansson (2013) Osmoregulation and growth in offspring of wild Atlantic salmon at different temperatures Environmental Biology of Fishes, DOI 10.1007/s10641-013-0151-5

10.    Handeland SO, AK Imsland, LOE Ebbesson, TO Nilsen, CD Hosfeld, G Baeverfjord, Å Espmark, T Rosten, OT Skilbrei, T Hansen, GS Gunnarsson, O Breck, SO Stefansson (2013) Low light intensity can reduce Atlantic salmon smolt quality. Aquaculture 384–387:19-24

11.    Urke HA, T Kristensen, JV Arnekleiv, TO Haugen, G Kjærstad, SO Stefansson, LOE Ebbesson, TO Nilsen (2013). Seawater tolerance and post-smolt migration of wild Atlantic salmon Salmo salar x brown trout S. trutta hybrid smolts. Journal of Fish Biology 82: 206–227.

12.    Ebbesson LOE and Braithwaite VA (2012). Environmental impacts on fish neural plasticity and cognition. Journal of Fish Biology 81, 2151-2174.

13.    Sandbakken M, LOE Ebbesson, SO Stefansson, JV Helvik (2012) Isolation and characterization of melanopsin photoreceptors of Atlantic salmon (Salmo salar). J Comparative Neurology. 520:3727-44.

14.    Ebbesson SO, JC Lopez-Alvarenga, PM Okin, RB Devereux, ME Tejero, WS Harris, LO Ebbesson, JW MacCluer, C Wenger, S Laston, RR Fabsitz, J Kennish, WJ Howard, BV Howard, J Umans, AG Comuzzie (2012) Heart rate is associated with markers of fatty acid desaturation: the GOCADAN study. Int J Circumpolar Health. doi: 10.3402/ijch.v71i0.17343.

15.    Kroglund K, Finstad B, Pettersen K, Teien HC, Salbu B, Rosseland BO, Nilsen TO, Stefansson SO, Ebbesson LOE, Nilsen R, Bjørn PA, Kristensen T (2012) Recovery rates in Atlantic salmon smolts following aluminum exposure defined by changes in blood physiology and salmon lice resistance. Aquaculture. 362–363: 232-240.

16.    Finstad B, Kroglund K, Bjørn PA, Pettersen K, Rosseland BO, Teien HC, Nilsen TO, Stefansson SO, Salbu B, Nilsen R, Fiske P, Ebbesson LOE (2012) Salmon lice induced mortality of Atlantic salmon postsmolts experiencing episodic acidification and recovery in freshwater. Aquaculture. 362–363: 193-199.

17.    Stefansson SO, Haugland M, Björnsson BTh, McCormick SD, Holm M, Ebbesson LOE, Holst JC, Nilsen TO (2012) Growth, osmoregulation and endocrine changes in wild Atlantic salmon post-smolts during marine migration. Aquaculture, 127-136.

18.    Ebbesson LOE, Nilsen TO, Helvik JV, Tronci V and Stefansson SO (2011) Corticotropin-releasing factor neurogenesis during midlife development in salmon: genetic, environment and thyroid hormone regulation. J Neuroendocrinology. 23:733-741.

19.    Ebbesson SOE, Devereux RB, Cole S, Ebbesson LOE, Fabsitz RR, Haack K, Harris WS, Howard WJ, Laston S, Lopez-Alvarenga JC, MacCluer JW, Okin PM, Tejero ME, Voruganti VS, Wenger CR, Howard BV, Comuzzie AG (2010) Heart rate is associated with red blood cell fatty acid concentration: The Genetics of Coronary Artery Disease in Alaska Natives (GOCADAN) study. American Heart Journal. 159(6): 1020-5.

20.    Ebbesson SOE, Tejero ME, Lopez-Alvarenga JC, Harris WS, Ebbesson LOE, Devereux RB, MacCluer JW, Wenger C, Laston S, Fabsitz RR, Howard BV, Comuzzie AG (2010) Individual saturated fatty acids are associated with different components of insulin resistance and glucose metabolism: the GOCADAN study. Int J Circumpolar Health. 69(4): 344-51.

21.    Nilsen TO, LOE Ebbesson, OG Kverneland, F Kroglund, B Finstad, SO Stefansson (2010) Effects of acidic water and aluminum exposure on gill Na+, K+ ATPase – alpha subunit isoforms, enzyme activity, physiology and return rates in Atlantic salmon (Salmo salar L.). Aquatic Toxicology 97: 250-259.

22.    Lopez-Alvarenga JC, Ebbesson SOE, Ebbesson LOE, Tejero ME, Vorugantia VS, Comuzzi AG (2010) Polyunsaturated fatty acids effect on serum triglycerides concentration in the presence of metabolic syndrome components. The Alaska-Siberia Project. Metabolism 59:86-92

23.    Murashita K, Kurokawa T, Ebbesson LOE, Stefansson SO, Rønnestad I (2009) Characterization, tissue distribution, and regulation of agouti-related protein (AgRP), cocaine- and amphetamine-regulated transcript (CART) and neuropeptide Y (NPY) in Atlantic salmon (Salmo salar). Gen. Comp. Endocrinol. 162:160-71

24.    Ebbesson, LOE, Björnsson, BTh, Ekström, P, Stefansson, SO. (2008) Daily endocrine profiles in parr and smolt Atlantic salmon.  Comp. Biochem. Physiol. A, 151, 698-704.

25.    Ebbesson SOE, Roman MJ, Devereux RB, Kaufman D, Fabsitz RR, Maccluer JW, Dyke B, Laston S, Wenger CR, Comuzzie AG, Romenesko T, Ebbesson LOE, Nobmann ED, Howard BV. (2008) Consumption of omega-3 fatty acids is not associated with a reduction in carotid atherosclerosis: The Genetics of Coronary Artery Disease in Alaska Natives study. Atherosclerosis. 199(2):346-53

26.    Nilsen TO, Ebbesson LOE, Kiilerich P, Björnsson BTh, Madsen SS, McCormick SD, Stefansson SO. (2008) Endocrine systems in juvenile anadromous and landlocked Atlantic salmon (Salmo salar): Seasonal development and seawater acclimation. General Comparative Endocrinology. 155:762-772

27.    Tipsmark CK, P Kiilerich, TO Nilsen, LOE Ebbesson, SO Stefansson and SS Madsen (2008) Branchial expression patterns of claudin isoforms in Atlantic salmon during seawater acclimation and smoltification. American Journal Physiology 294: R1563–R1574.

28.    Ebbesson SO, Tejero ME, Nobmann ED, Lopez-Alvarenga JC, Ebbesson LOE, Romenesko T, Carter EA, Resnick HE, Devereux RB, Maccluer JW, Dyke B, Laston SL, Wenger CR, Fabsitz RR, Comuzzie AG, Howard BV. (2007) Fatty Acid Consumption and Metabolic Syndrome Components: The GOCADAN Study. Journal Cardiometabolic Syndrome 2(4): 244-249.

29.    Ebbesson LOE, Ebbesson SOE, Nilsen TO, Stefansson SO and Holmqvist B 2007. Exposure to continuous light disrupts retinal innervation of the preoptic nucleus during parr-smolt transformation in Atlantic salmon. Aquaculture 273: 345-349.

30.    Nilsen TO, Ebbesson LOE, Madsen SS, McCormick SD, Andersson E, Björnsson BTh, Prunet P, Stefansson SO.(2007) Differential expression of gill Na+,K+-ATPase alpha- and beta-subunits, Na+,K+,2Cl- cotransporter and CFTR anion channel in juvenile anadromous and landlocked Atlantic salmon Salmo salar. Journal of Experimental Biology 210:2885-96.

31.    Stefansson SO, TO Nilsen, LOE Ebbesson, A Wargelius, SS Madsen, BT Björnsson & SD McCormick (2007) Molecular mechanisms of continuous light inhibition of Atlantic salmon parr–smolt transformation. Aquaculture 273: 235–245

32.    Richardson SJ, Monk JA, Shepherdley CA, Ebbesson LOE, Sin F, Power DM, Frappell PB, Köhrle J and Renfree MB (2005). Developmentally regulated thyroid hormone distributor proteins in marsupials, a reptile and fishes. American Journal of Physiology 288(5):R1264-72

33.    Ebbesson, LOE, CK Tipsmark, B Holmqvist, T Nilsen, E Andersson, SO Stefansson and SS Madsen (2005a). Nitric oxide synthase in the gill of Atlantic salmon: co-localization with and inhibition of Na+,K+-ATPase. Journal of Experimental Biology 208:1011-7

34.    Ebbesson SOE, AI Adler , PM Risica, LOE Ebbesson, J-L Yeh, OT Go, W Doolittle, G Ehlert, M Swenson, DC Robbins (2005b)Cardiovascular disease and risk factors in three Alaskan Eskimo populations: The Alaska-Siberia Project. Int J Circumpolar Health ; 64(4): 365-386

35.    Ebbesson SOE, PM Risica, LOE Ebbesson, JM Kennish, ME Tejero (2005c) Omega 3 fatty acids improve glucose tolerance and components of the metabolic syndrome in Alaskan Eskimos: the Alaska Siberia Project. Int J Circumpolar Health 64(4): 396-408

36.    Ebbesson SOE, PM Risica, LOE Ebbesson, JM Kennish (2005d) Eskimos have CHD despite high consumption of omega-3 fatty acids: The Alaska Siberia projects. Int J Circumpolar Health 64(4): 387-395

37.    Ebbesson SOE, LOE Ebbesson, M Swenson, JM Kennish, DC Robbins (2005e)  A successful diabetes prevention study in Eskimos: The Alaska Siberia project. Int J Circumpolar Health 64(4): 409-424

38.    Kulczykowska, E., Sokolowska, E., Takvam, B., Stefansson, S.O., Ebbesson, L.O.E. (2004) Influence of exogenous thyroxine on plasma melatonin in juvenile Atlantic salmon (Salmo salar). Comparative Biochemistry and Physiology: Part B 137: 43-47

39.    Ebbesson, L.O.E., P. Ekström, S.O.E. Ebbesson, S.O. Stefansson, and B. Holmqvist. (2003). Neural circuits and their structural and chemical reorganization in the light-brain-pituitary axis during parr-smolt transformation in salmon. Aquaculture 222: 59-70.

40.    Nilsen, T, Ebbesson, L.O.E., Stefansson S.O. (2003) Smolting in anadromous and landlocked strains of Atlantic salmon (Salmo salar). Aquaculture 222: 71-82

41.    Drivenes, Ø, A. M. Søviknes, L.O.E. Ebbesson, A. Fjøse, H-C. Seo and J. V. Helvik.(2003) Isolation and characterisation of two teleost melanopsin genes and their differential expression within the inner retina and brain. Journal of Comparative Neurology 456: 84-93

42.    Ebbesson, L.O.E., B.Th. Björnsson, S.O. Stefansson, and P. Ekström (2000). Free-thyroxine during parr-smolt transformation in coho salmon, Oncorhynchus kisutch: Comparison with total thyroxine, total triiodothyronine, and growth hormone. Fish Physiol Biochem 22: 45-50

43.    Ágústsson, Th., L.O.E. Ebbesson, B.Th. Björnsson (2000) Dopaminergic innervation of the rainbow trout pituitary and stimulatory effect of dopamine on growth hormone secretion in vitro. Comparative Biochemistry and Physiology Part A 127:355-364

44.    Ebbesson SOE, J Kennish, LOE Ebbesson, O Go, J Yeh (1999) Diabetes is related to fatty acid imbalance in Eskimos. Int J Circumpolar Health 58: 108-119.

45.    Ebbesson, LOE, BTh Björnsson, SO Stefansson, and P Ekström (1998a). Propylthiouracil-induced hypothyroidism in coho salmon, Oncorhynchus kisutch: Effects on plasma total thyroxine, total triiodothyronine, free thyroxine, and growth hormone. Fish Physiol Biochem 19: 305-313

46.    Ebbesson, S.O.E., C. D. Schraer, P. M. Risica, A.I. Adler, L.O.E. Ebbesson, A.M. Mayer, E.V. Shubnikof, J. Yeh, O.T. Go, and D. Robbins (1998b) Diabetes and impaired glucose tolerance in three Alaskan Eskimo populations. Diabetes Care 21 (4): 563-569

47.    Ebbesson, L.O.E., P. Deviche, and S.O.E. Ebbesson (1996a). Distribution and changes in mu- and kappa-opiate receptors during the midlife neurodevelopmental period of coho salmon, Oncorhynchus kisutch. Journal of Comparative Neurology 366: 448-464.

48.    Ebbesson, S.O.E., J. Smith, C. Co, and L.O.E. Ebbesson (1996b). Transient alterations in neurotransmitter levels during a critical period of neural development in coho salmon (Oncorhyncus kisutch). Brain Research 742, 339-342.

49.    Ebbesson, S.O.E., C. Schraer, E.D. Nobmann, and L.O.E. Ebbesson (1996c) Lipoprotein profiles in Alaskan Siberian Yupik Eskimos. Arctic Medical Research 55, 165-173

50.    Ebbesson, L.O.E., B. Holmqvist, T. Östholm, and P. Ekström (1992). Transient serotonin-immunoreactive neurons coincide with a critical period of neural development in coho salmon (Oncorhyncus kisutch). Cell Tissue Research 268, 389-392.

51.    Keller, J.W., Baurick, K. B., Rutt, G. C. O., Malley, M. V., Sonafrank, N. L., Reynolds, R. A., Ebbesson, L. O. E., Vajdos,  F. F. (1990). Pseudomonas cepacia 2,2’-dialkylglycine decarboxylase: Sequence and expression in Escherichia coli of structural and repressor genes. Journal of Biological Chemistry 265, 5531-5539


Book chapters

1.   Stefansson SO, Björnsson BTh, Ebbesson LOE, McCormick SD. (2008) Smoltification. In Fish Larval Physiology (Finn & Kapoor, eds.). 639-681. ISBN 978-1-57808-388-6.

2.   Holmqvist B, Ebbesson LOE, Alm P (2007). Nitric oxide in developmental neurobiology of zebrafish. Review. In "Nitric oxide", Advances in Experimental Biology series, Tota B and Trimmer B (eds). (Elsevier, Amsterdam), Vol 1. pp 229-274.


Popular science and reports

  1.    Nilsen TO, Ebbesson LOE, Kverneland OG, Kroglund F, Finstad B, Stefansson SO (2010) Ny metode kan påvise skader hos laksesmolt som er utsatt for aluminiumsrikt surt vann. pH-status nr. 4:12-13.
  2.    Kroglund F, B Finstad, K Pettersen, BO Rosseland, PA Bjørn, HC Teien, B Salbu, TO Nilsen, S Stefansson, L Ebbesson, R Nilsen, T Kristiansen (2010) Forsurigsskader og helbredningstid for laksesmolt. pH-status nr.1: 6-7.
  3. Ebbesson LOE (2009) Brain development. In Helvik JV, Hamre K, Hordvik I, van der Meeren T, Ressem H Tveiten H, Øie G, Schartl M (2009) The fish larva: a transitional life form, the foundation for aquaculture and fisheries. Report from a working group on research on early life stages of fish. The Research Council of Norway. ISBN 978-82-12-02681-0. 74 pp.






Alle artikler


  • Stefansson, Sigurd Olav; Bjørnsson, B. Th.; Ebbesson, Lars O.E.; McCormick, S.D. Smoltification. I: Fish Larval Physiology. Science Publishers Inc. 2008 ISBN 978-1-57808-388-6.. sider 607-681
  • Holmqvist, B.; Ebbesson, Lars; Alm, P. Nitric oxide in developmental neurobiology of zebrafish. Review. I: Nitric oxide (Advances in Experimental Biology Series). Elsevier 2007 ISBN 978-0-444-53119-3.. sider 229-274

Andre publikasjoner

  • Balseiro Vigo, Pablo; Moe, Øyvind; Gamlem, Ingrid; Shimizu, Munetaka; Sveier, Harald; Nilsen, Tom Ole; Ebbesson, Lars O.E.; Pedrosa, Cindy; Tronci, Valentina; Nylund, Are; Handeland, Sigurd O Muscle development and heart condition in Atlantic salmon (Salmo salar) post-­smolts reared in Preline S-CCS. 2017.
  • Good, Christopher; Summerfelt, S.; May, T.; Crouse, C.; Ebbesson, Lars O.E.; Handeland, Sigurd O; Stefansson, Sigurd Olav; Nilsen, Tom Ole; Terjesen, B.F.; Mathisen, F. The effects of photoperiod on Atlantic salmon post-smolt in freshwater closed-containment systems. 2017.
  • Ebbesson, Lars O.E.; Hellesund, Dag Samlar bærekraftig oppdrettsforsking på perfekt tidspunkt. 2016.
  • Handeland, Sigurd O; Ebbesson, Lars O.E. Lovende resultater for produksjon av laks i lukkede anlegg. 2016.
  • Vindas, Marco Antonio; Gorissen, Marnix; Höglund, Erik; Flik, G.; Tronci, Valentina; Damsgård, Børge; Thörnqvist, Per-Ove; Nilsen, Tom Ole; Winberg, Svante; Øverli, Øyvind; Ebbesson, Lars O.E. How do individuals cope with stress? A neuroendocrine substrate for proactive and reactive coping styles in fish. 2016.
Alle andre publikasjoner
Se alle publikasjoner i CRIStin

Pågående prosjekter

Alle prosjekter
cp: 2019-12-04 11:15:23