Jensen group – Evolutionary adaptation to high cardiac performance
When we compare the heart of a fish to that of a human, it is readily observed that we have 2 atria rather than 1 atrium and two ventricles rather than one. We are fascinated by such evolutionary changes to the heart. Our approach is comparative, where a multitude of species are studied to infer evolutionary history. Thus, we are continuing down the path of Charles Darwin. We use techniques of anatomy, electrophysiology, and molecular biology. Our favorite preoccupations are to identify the evolutionary adaptations that have enabled hearts of mammals to pump much greater volumes of blood than the hearts of the evolutionary siblings of reptiles and amphibians.
Philosophy: great insights come from curiosity, curiosity blossoms in freedom, freedom is given if you are competent.
Contact: B. Jensen (email@example.com)
3D Atlas of the developing human heart: visualizations of human heart development are mostly based on hearts from mouse and chicken, which show resemblance to the human heart, but do not capture a number of important features. Jaeike is currently making 3D models of embryonic human hearts from the linear heart tube stage to the end of the embryonic period when most important morphogenetic processes have begun. The models of based on immunohistochemically stained histological sections and may serve as reference models to the Human Cell Atlas.
The atria of birds: the atria of mammals are profoundly remodeled compared to reptiles. If these changes are necessary adaptation for great cardiac outputs, similar changes must be expected in the atria of birds. Jelle is currently making an anatomical characterization of 10 structures of the bird atria to enable the analysis between mammals and birds.
Ventricular wall formation: the process of ventricular wall formation is receiving great interest since the categorization of Left Ventricular Noncompaction as a distinct cardiomyopathy.
LVNC in human fetuses
Left ventricular noncompaction is a recently recognized cardiomyopathy characterized by excessive trabeculations. It is thought to be the aberrant retention of an embryonic and evolutionary old program. Using immunohistochemistry, we show in fetal cases of noncompaction that the excessive trabeculations do not have the embryonic identity: the pathologic culprit is likely aberrant growth of the compact wall.
Morpho-functional venous pole
In reptiles, filling of the right atrium is aided by the contractions of the upstream chamber, the sinus venosus, which is endowed with a sinuatrial delay and a competent valve. Mammals retain the muscle of the sinus venosus, but have lost the delay and valve. These losses are puzzling because the muscle of the mammal sinus venosus is thought to aid atrial filling. Possibly, high heart rates make it mechanically disadvantageous to have three chambers – sinus venosus, atrium, ventricle – beating in sequence.
- MacIver DH, Stephenson RS, Jensen B, Agger P, Sánchez-Quintana D, Jarvis JC, Partridge JB, Anderson RH. The end of the unique myocardial band: Part I. Anatomical considerations. Eur J Cardiothorac Surg. 2018 Jan 1;53(1):112-119. doi.org/10.1093/ejcts/ezx290 www.ncbi.nlm.nih.gov/pubmed/28958005
- Cook AC, Tran VH, Spicer DE, Rob JMH, Sridharan S, Taylor A, Anderson RH, Jensen B. Sequential segmental analysis of the crocodilian heart. J Anat. 2017 Oct;231(4):484-499. doi.org/10.1111/joa.12661 www.ncbi.nlm.nih.gov/pubmed/28766716
- Jensen B, Vesterskov S, Boukens BJ, Nielsen JM, Moorman AFM, Christoffels VM, Wang T. Morpho-functional characterization of the systemic venous pole of the reptile heart. Sci Rep. 2017 Jul 27;7(1):6644. doi.org/10.1038/s41598-017-06291-z www.ncbi.nlm.nih.gov/pubmed/28751678
- Anderson RH, Jensen B, Mohun TJ, Petersen SE, Aung N, Zemrak F, Planken RN, MacIver DH. Key Questions Relating to Left Ventricular Noncompaction Cardiomyopathy: Is the Emperor Still Wearing Any Clothes? Can J Cardiol. 2017 Jun;33(6):747-757. doi.org/10.1016/j.cjca.2017.01.017 www.ncbi.nlm.nih.gov/pubmed/28395867
- Jensen B, Spicer DE, Sheppard MN, Anderson RH. Development of the atrial septum in relation to postnatal anatomy and interatrial communications. Heart. 2017 Mar;103(6):456-462. doi.org/10.1136/heartjnl-2016-310660 www.ncbi.nlm.nih.gov/pubmed/28003417
- Jensen B, van der Wal AC, Moorman AFM, Christoffels VM. Excessive trabeculations in noncompaction do not have the embryonic identity. Int J Cardiol. 2017 Jan 15;227:325-330. doi.org/10.1016/j.ijcard.2016.11.089 www.ncbi.nlm.nih.gov/pubmed/27838129
- Jensen B, Agger P, de Boer BA, Oostra RJ, Pedersen M, van der Wal AC, Nils Planken R, Moorman AF. The hypertrabeculated (noncompacted) left ventricle is different from the ventricle of embryos and ectothermic vertebrates. Biochim Biophys Acta. 2016 Jul;1863(7 Pt B):1696-706. doi.org/10.1016/j.bbamcr.2015.10.018 www.ncbi.nlm.nih.gov/pubmed/26516055
- Jensen B, Elfwing M, Elsey RM, Wang T, Crossley DA 2nd. Coronary blood flow in the anesthetized American alligator (Alligator mississippiensis). Comp Biochem Physiol A Mol Integr Physiol. 2016 Jan;191:44-52. doi.org/10.1016/j.cbpa.2015.09.018 www.ncbi.nlm.nih.gov/pubmed/26436857
- de Bakker DM, Wilkinson M, Jensen B. Extreme variation in the atrial septation of caecilians (Amphibia: Gymnophiona). J Anat. 2015 Jan;226(1):1-12. doi.org/10.1111/joa.12255 www.ncbi.nlm.nih.gov/pubmed/25400089
- Poelmann RE, Gittenberger-de Groot AC, Vicente-Steijn R, Wisse LJ, Bartelings MM, Everts S, Hoppenbrouwers T, Kruithof BP, Jensen B, de Bruin PW, Hirasawa T, Kuratani S, Vonk F, van de Put JM, de Bakker MA, Richardson MK. Evolution and development of ventricular septation in the amniote heart. PLoS One. 2014 Sep 5;9(9):e106569. doi.org/10.1371/journal.pone.0106569. www.ncbi.nlm.nih.gov/pubmed/25192012
- Jensen B, Moorman AF, Wang T. Structure and function of the hearts of lizards and snakes. Biol Rev Camb Philos Soc. 2014 May;89(2):302-36. doi.org/10.1111/brv.12056
- Jensen B, van den Berg G, van den Doel R, Oostra RJ, Wang T, Moorman AF. Development of the hearts of lizards and snakes and perspectives to cardiac evolution. PLoS One. 2013 Jun 5;8(6):e63651. doi.org/10.1371/journal.pone.0063651 https://www.ncbi.nlm.nih.gov/pubmed/23755108
- Jensen B, Wang T, Christoffels VM, Moorman AF. Evolution and development of the building plan of the vertebrate heart. Biochim Biophys Acta. 2013 Apr;1833(4):783-94. doi.org/10.1016/j.bbamcr.2012.10.004 https://www.ncbi.nlm.nih.gov/pubmed/23063530
- Jensen B, Boukens BJ, Postma AV, Gunst QD, van den Hoff MJ, Moorman AF, Wang T, Christoffels VM. Identifying the evolutionary building blocks of the cardiac conduction system. PLoS One. 2012;7(9):e44231. doi.org/10.1371/journal.pone.0044231 https://www.ncbi.nlm.nih.gov/pubmed/22984480
- Jensen B, Larsen CK, Nielsen JM, Simonsen LS, Wang T. Change of cardiac function, but not form, in postprandial pythons. Comp Biochem Physiol A Mol Integr Physiol. 2011 Sep;160(1):35-42. doi.org/10.1016/j.cbpa.2011.04.018 https://www.ncbi.nlm.nih.gov/pubmed/21605694
- Jensen B, Abe AS, Andrade DV, Nyengaard JR, Wang T. The heart of the South American rattlesnake, Crotalus durissus. J Morphol. 2010 Sep;271(9):1066-77. doi.org/10.1002/jmor.10854 https://www.ncbi.nlm.nih.gov/pubmed/20730920
- Jensen B, Nielsen JM, Axelsson M, Pedersen M, Löfman C, Wang T. How the python heart separates pulmonary and systemic blood pressures and blood flows. J Exp Biol. 2010 May;213(Pt 10):1611-7. doi.org/10.1242/jeb.030999 https://www.ncbi.nlm.nih.gov/pubmed/20435810
- Jensen B, Nyengaard JR, Pedersen M, Wang T. Anatomy of the python heart. Anat Sci Int. 2010 Dec;85(4):194-203. doi.org/10.1007/s12565-010-0079-1 https://www.ncbi.nlm.nih.gov/pubmed/20376590
- Rasmussen AS, Lauridsen H, Laustsen C, Jensen BG, Pedersen SF, Uhrenholt L, Boel LW, Uldbjerg N, Wang T, Pedersen M. High-resolution ex vivo magnetic resonance angiography: a feasibility study on biological and medical tissues. BMC Physiol. 2010 Mar 12;10:3. doi.org/10.1186/1472-6793-10-3 https://www.ncbi.nlm.nih.gov/pubmed/20226038
- Jensen B, Wang T. Hemodynamic consequences of cardiac malformations in two juvenile ball pythons (Python regius). J Zoo Wildl Med. 2009 Dec;40(4):752-6. www.ncbi.nlm.nih.gov/pubmed/20063822