Neuronal hypoxia tolerance in diving endotherms

• Main Author: Ludvigsen, Stian
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Universitetet i Tromsø 2010
• Subjects: VDP::Matematikk og naturvitenskap: 400::Zoologiske og botaniske fag: 480::Zoofysiologi og komparativ fysiologi: 483; VDP::Mathematics and natural science: 400::Zoology and botany: 480::Zoophysiology and comparative physiology: 483; VDP::Matematikk og naturvitenskap: 400::Zoologiske og botaniske fag: 480::Marinbiologi: 497; VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497; VDP::Medisinske fag: 700::Basale medisinske; odontologiske og veterinærmedisinske fag: 710::Farmakologi: 728; VDP::Medical disciplines: 700::Basic medical; dental and veterinary science disciplines: 710::Pharmacology: 728; hypoxia; brain; diving animals; KATP-channels; capillary density; Messelt; Ramirez; Cystophora cristata; hooded seal; Somateria mollissima
• Online Access: https://hdl.handle.net/10037/2788

The papers of the thesis are not available in Munin: 1. L.P. Folkow, J.M. Ramirez, S. Ludvigsen, N. Ramirez, A.S. Blix: "Remarkable neuronal hypoxia tolerance in the deep-diving adult hooded seal (Cystophora cristata)" Neuroscience Letters, vol 446 (2008), 147-150 (Elsevier - publisher's restrictions). Available at http://dx.doi.org/10.1016/j.neulet.2008.09.040 2. J.M. Ramirez, L.P. Folkow, S. Ludvigsen, N. Ramirez, A.S. Blix: "Spontaneous and persistent activity in thick neocortical slices of the deep-diving hooded seal" (manuscript) 3. S. Ludvigsen, L.P. Folkow: "Differences in in vitro cerebellar neuronal responses to hypoxia in eider ducks, chicken and rats", Journal of Comparative Physiology A, Vol 195 (2009), no 11, 1021-1030 (Springer - publisher's restrictions). Available at http://dx.doi.org/10.1007/s00359-009-0476-x 4. S. Geiseler, S. Ludvigsen, L.P. Folkow: "KATP-channels and their possible contribution to neuronal hypoxia tolerance in the cerebellum of eider ducks (Somateria mollissima)" (manuscript) 5. S. Ludvigsen, L.P. Folkow, E.B. Messelt: "Brain capillary density in the deepdiving hooded seal (Cystophora cristata)" (manuscript) The thesis “Neuronal hypoxia tolerance in diving endotherms” sheds light on mechanisms giving diving animals, such as the hooded seal, impressive dive capabilities of 1 hr duration down to 1000 m depth. In spite of enhanced capacity to store oxygen in their body and an ability to reduce their oxygen-consumption, these animals can resurface with blood oxygen values so low that a human being in the same situation would loose consciousness within seconds. This implies that the brain of diving animals tolerate lack of oxygen much better than the brain of non-diving animals. In the thesis it is demonstrated for the first time that this is actually the case. Electrophysiological recordings of isolated brain slices were used to investigate how neuronal activity changed in response to hypoxia in brain tissue from hooded seals (Cystophora cristata) (Folkow et al., 2008) and ...