Siddiqui, Maheen Faisal (2019) Combined measures of oxygenation, haemodynamics and metabolism to understand neural responses in infants. Doctoral thesis, Birkbeck, University of London.
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Abstract
fNIRS is an established research tool used to investigate typical and atypical brain development.Primarily, it provides measures of haemodynamic changes that are used to indirectly infer neural activity. Broadband NIRS provides a more direct marker of neuronal activation through measurement of changes in cytochrome-c-oxidase (CCO). As a cellular measure, CCO can be used as a bridge to improve our understanding of the link between neural and haemodynamic activity or “neurovascular coupling”. Study 1 demonstrated that changes in mitochondrial activity could be measured alongside haemodynamics during functional activation, over the temporal cortex, using a miniature system in four-to-six-month-old infants. In order to investigate the spatial specificity of CCO, its relation to haemodynamics and to build upon our understanding of neurovascular coupling mechanisms, multi-channel broadband NIRS was used alongside EEG in Study 2 where responses were measured over the visual cortex. Study 2 was performed in adults as the development of a concurrent NIRS and EEG protocol was methodologically challenging. Following this, Study 3 extended on experimental paradigms from Studies 1 and 2 to measure changes in metabolic activity and haemodynamics over the temporal and visual cortices, in four-to-seven-month-old infants. This study demonstrated simultaneous broadband NIRS and EEG use in infants for the first time. The results provided evidence of underdeveloped coupling of cerebral blood flow changes and mitochondrial activity in early infancy. Finally, Study 4 extended the protocol to investigate underlying biological mechanisms that may be altered in neurovascular coupling in autism, by studying infants at high familial risk for the disorder. The findings demonstrated that the combined protocol was not only feasible for use to study atypical brain development but also provided preliminary evidence of altered coupling between cerebral energy metabolism and haemodynamics.Taken together, this work illuminates hitherto undocumented evidence of neurovascular coupling during brain development and highlights the potential of using broadband NIRS with EEG for future neurodevelopmental research in typical and atypical populations.
Metadata
Item Type: | Thesis |
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Additional Information: | Date of PhD award confirmed as 2019 by registry |
Copyright Holders: | The copyright of this thesis rests with the author, who asserts his/her right to be known as such according to the Copyright Designs and Patents Act 1988. No dealing with the thesis contrary to the copyright or moral rights of the author is permitted. |
Depositing User: | Acquisitions And Metadata |
Date Deposited: | 10 Jul 2019 11:14 |
Last Modified: | 28 Jun 2024 14:11 |
URI: | https://eprints.bbk.ac.uk/id/eprint/40399 |
DOI: | https://doi.org/10.18743/PUB.00040399 |
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