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dc.contributor.advisorGeiseler, Samuel
dc.contributor.advisorFolkow, Lars
dc.contributor.authorTorppa, Sara
dc.date.accessioned2024-01-12T11:46:53Z
dc.date.available2024-01-12T11:46:53Z
dc.date.issued2023-11-15
dc.description.abstractTo maintain normal neuronal function, the mammalian brain requires a constant supply of energy. The deep-diving hooded seal (<i>Cystophora cristata</i>) brain exhibits remarkable tolerance to extreme hypoxia, presumably involving a reduction in brain activity to lower energy demand. Thus, some neurons, circuits or even regions in the seal’s brain presumably display a neural protective shutdown response to achieve this. The mechanisms behind this response as yet remain incompletely understood, but there are several factors that may contribute. Lactate, beyond its metabolic role, has been demonstrated to have signaling effects, and the lactate receptor HCAR1 is expressed in the human and rodent brain. Activation of HCAR1 has been observed to slow neuronal firing, inhibit excitatory transmission, and have other beneficial cerebral effects. This thesis investigates the role of the receptor in the hypoxia- tolerant hooded seal. Using qPCR analysis, the HCAR1 was shown to be expressed in several brain regions of hooded seals. Electrophysiological experiments, employing field recordings of excitatory post-synaptic potentials (fEPSP) were conducted to measure synaptic transmission in hippocampal slices from hooded seals. These recordings were performed with and without activating HCAR1 using lactate and non-metabolic agonists. Parallel experiments were conducted in mice to compare possible differences between hooded seals and non- hypoxia-tolerant animals. Both lactate and its agonist 3,5-DHBA demonstrated a suppressing effect on synaptic transmission activity in both hooded seals and mice. The results indicate that during the deep and prolonged dives of hooded seals, when energy is generated anaerobically in the brain, increased lactate levels activate HCAR1, leading to the suppression of synaptic activity. This mechanism potentially contributes to the neural protective shutdown observed in hooded seals.en_US
dc.identifier.urihttps://hdl.handle.net/10037/32441
dc.language.isoengen_US
dc.publisherUiT Norges arktiske universiteten_US
dc.publisherUiT The Arctic University of Norwayen_US
dc.rights.accessRightsopenAccessen_US
dc.rights.holderCopyright 2023 The Author(s)
dc.rights.urihttps://creativecommons.org/licenses/by-nc-sa/4.0en_US
dc.rightsAttribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)en_US
dc.subject.courseIDBIO-3950
dc.subjecthooded sealen_US
dc.subject(Cystophora cristata)en_US
dc.subjectlactateen_US
dc.subjectHCAR1en_US
dc.subjecthypoxiaen_US
dc.subjectbrainen_US
dc.subjecthippocampusen_US
dc.subjectfEPSPen_US
dc.subjectelectrophysiologyen_US
dc.titleRole of the lactate receptor HCAR1 as part of neural adaptations to hypoxia in hooded seals (Cystophora cristata)en_US
dc.typeMaster thesisen_US
dc.typeMastergradsoppgaveen_US


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Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)