@article{discovery10060791,
            year = {2018},
       publisher = {Frontiers Media},
         journal = {Frontiers in Neuroscience},
           title = {Challenges and perspectives of quantitative functional sodium imaging (fNaI)},
          volume = {12},
            note = {{\copyright} 2018 Gandini Wheeler-Kingshott, Riemer, Palesi, Ricciardi, Castellazzi, Golay, Prados, Solanky and D'Angelo. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY) (http://creativecommons.org/licenses/by/4.0/). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.},
           month = {November},
             url = {https://doi.org/10.3389/fnins.2018.00810},
            issn = {1662-4548},
        keywords = {sodium imaging, functional imaging, neuronal activity, BOLD, MRI},
        abstract = {Brain function has been investigated via the blood oxygenation level dependent (BOLD) effect using magnetic resonance imaging (MRI) for the past decades. Advances in sodium imaging offer the unique chance to access signal changes directly linked to sodium ions (23Na) flux across the cell membrane, which generates action potentials, hence signal transmission in the brain. During this process 23Na transiently accumulates in the intracellular space. Here we show that quantitative functional sodium imaging (fNaI) at 3T is potentially sensitive to 23Na concentration changes during finger tapping, which can be quantified in gray and white matter regions key to motor function. For the first time, we measured a 23Na concentration change of 0.54 mmol/l in the ipsilateral cerebellum, 0.46 mmol/l in the contralateral primary motor cortex (M1), 0.27 mmol/l in the corpus callosum and -11 mmol/l in the ipsilateral M1, suggesting that fNaI is sensitive to distributed functional alterations. Open issues persist on the role of the glymphatic system in maintaining 23Na homeostasis, the role of excitation and inhibition as well as volume distributions during neuronal activity. Haemodynamic and physiological signal recordings coupled to realistic models of tissue function will be critical to understand the mechanisms of such changes and contribute to meeting the overarching challenge of measuring neuronal activity in vivo.},
          author = {Wheeler-Kingshott, CAM and Riemer, F and Palesi, F and Ricciardi, A and Castellazzi, G and Golay, X and Prados Carrasco, F and Solanky, B and D'Angelo, EU}
}