Papers by Taneli Hautaniemi
The Journal of Neuroscience, 2022
Oura Health Ltd.'s provided the surveillance smart rings for the study, but did not participate i... more Oura Health Ltd.'s provided the surveillance smart rings for the study, but did not participate in the analysis. The manuscript in question is published as a preprint in bioRxiv, but we guarantee that it does not infringe any subsequent copyright or license agreement. 3 3 We would like to thank all study subjects for their participation in the study. We also thank Tuomas Konttajärvi for assistance in measurements and preprocessing of EEG data, Jani Häkli, Annastiina Kivipää, Tarja Holtinkoski, Aleksi Rasila, Taneli Hautaniemi, Miia Lampinen and others who assisted in measurements or otherwise contributed. We are grateful for devices and data provided by Oura. We wish to acknowledge Jussi Kantola for data management and reconstruction of MREG data, the CSC-IT Center for Science Ltd.
NeuroImage: Clinical, 2019
Epilepsy causes measurable irregularity over a range of brain signal frequencies, as well as auto... more Epilepsy causes measurable irregularity over a range of brain signal frequencies, as well as autonomic nervous system functions that modulate heart and respiratory rate variability. Imaging dynamic neuronal signals utilizing simultaneously acquired ultra-fast 10 Hz magnetic resonance encephalography (MREG), direct current electroencephalography (DC-EEG), and near-infrared spectroscopy (NIRS) can provide a more comprehensive picture of human brain function. Spectral entropy (SE) is a nonlinear method to summarize signal power irregularity over measured frequencies. SE was used as a joint measure to study whether spectral signal irregularity over a range of brain signal frequencies based on synchronous multimodal brain signals could provide new insights in the neural underpinnings of epileptiform activity. Methods: Ten patients with focal drug-resistant epilepsy (DRE) and ten healthy controls (HC) were scanned with 10 Hz MREG sequence in combination with EEG, NIRS (measuring oxygenated, deoxygenated, and total hemoglobin: HbO, Hb, and HbT, respectively), and cardiorespiratory signals. After pre-processing, voxelwise SE MREG was estimated from MREG data. Different neurophysiological and physiological subfrequency band signals were further estimated from MREG, DC-EEG, and NIRS: fullband (0-5 Hz, FB), near FB (0.08-5 Hz, NFB), brain pulsations in very-low (0.009-0.08 Hz, VLFP), respiratory (0.12-0.4 Hz, RFP), and cardiac (0.7-1.6 Hz, CFP) frequency bands. Global dynamic fluctuations in MREG and NIRS were analyzed in windows of 2 min with 50% overlap. Results: Right thalamus, cingulate gyrus, inferior frontal gyrus, and frontal pole showed significantly higher SE MREG in DRE patients compared to HC. In DRE patients, SE of cortical Hb was significantly reduced in FB (p = .045), NFB (p = .017), and CFP (p = .038), while both HbO and HbT were significantly reduced in RFP (p = .038, p = .045, respectively). Dynamic SE of HbT was reduced in DRE patients in RFP during minutes 2 to 6. Fitting to the frontal MREG and NIRS results, DRE patients showed a significant increase in SE EEG in FB in fronto-central and parieto-occipital regions, in VLFP in parieto-central region, accompanied with a significant decrease in RFP in frontal pole and parietal and occipital (O2, Oz) regions. Conclusion: This is the first study to show altered spectral entropy from synchronous MREG, EEG, and NIRS in DRE patients. Higher SE MREG in DRE patients in anterior cingulate gyrus together with SE EEG and SE NIRS results in 0.12-0.4 Hz can be linked to altered parasympathetic function and respiratory pulsations in the brain. Higher SE MREG in thalamus in DRE patients is connected to disturbances in anatomical and functional connections in epilepsy. Findings suggest that spectral irregularity of both electrophysiological and hemodynamic signals are altered in specific way depending on the physiological frequency range.
Journal of Cerebral Blood Flow & Metabolism, 2018
Ultra-fast functional magnetic resonance encephalography (MREG) enables separate assessment of ca... more Ultra-fast functional magnetic resonance encephalography (MREG) enables separate assessment of cardiovascular, respiratory, and vasomotor waves from brain pulsations without temporal aliasing. We examined effects of breath hold- (BH) related changes on cardiovascular brain pulsations using MREG to study the physiological nature of cerebrovascular reactivity. We used alternating 32 s BH and 88 s resting normoventilation (NV) to change brain pulsations during MREG combined with simultaneously measured respiration, continuous non-invasive blood pressure, and cortical near-infrared spectroscopy (NIRS) in healthy volunteers. Changes in classical resting-state network BOLD-like signal and cortical blood oxygenation were reproduced based on MREG and NIRS signals. Cardiovascular pulsation amplitudes of MREG signal from anterior cerebral artery, oxygenated hemoglobin concentration in frontal cortex, and blood pressure decreased after BH. MREG cardiovascular pulse amplitudes in cortical areas...
Neuroscience, 2012
Enhanced nociceptive firing in trigeminal ganglion neurons is a likely reason for migraine pain. ... more Enhanced nociceptive firing in trigeminal ganglion neurons is a likely reason for migraine pain. In experimental migraine-like conditions induced by the calcitonin gene-related peptide (CGRP), P2X3 receptors abundantly expressed in trigeminal neurons are highly responsive to the excitatory action of extracellular ATP. In this study, we tested whether naproxen, a common antimigraine medicine, could affect the function of P2X3 receptors in the presence or absence of the algogen nerve growth factor (NGF), the level of which is elevated in patients with chronic migraine. We used calcium imaging and patch clamp recordings from rat trigeminal neurons, which were activated by a relative specific P2X3 agonist α,β-meATP or by high potassium-induced depolarization. In the absence of NGF, naproxen dose-dependently (0.1-1 mM) reduced intracellular calcium transients elicited by α,β-meATP. Naproxen also led to a slight, but significant, reduction in calcium transients induced by potassium ions, indicating the involvement of voltage-gated calcium channels. The inhibitory action of 1 mM naproxen was enhanced after NGF pretreatment, suggesting that P2X3 receptors in sensitized neurons are more susceptible to inhibition by high doses of this nonsteroidal anti-inflammatory drug (NSAID). Using patch clamp recordings from HEK293 cells expressing P2X3 receptors, we tested the direct action of naproxen on P2X3 receptor-mediated membrane currents. In clinically relevant concentrations of 0.5 mM, naproxen produced a use-dependent blocking effect on ATP receptors. Kinetic analysis suggests that naproxen inhibited P2X3 receptors via facilitation of fast desensitization, which determines current decay in the continuous presence of the agonist. In summary, we present a novel fast mechanism for the antimigraine action of naproxen, which can act in synergy with the cyclooxygenase inhibition to attenuate headaches.
Journal of Cerebral Blood Flow & Metabolism
Ultra-fast functional magnetic resonance encephalography (MREG) enables separate assessment of ca... more Ultra-fast functional magnetic resonance encephalography (MREG) enables separate assessment of cardiovascular, respiratory, and vasomotor waves from brain pulsations without temporal aliasing. We examined effects of breath hold- (BH) related changes on cardiovascular brain pulsations using MREG to study the physiological nature of cerebrovascular reactivity. We used alternating 32 s BH and 88 s resting normoventilation (NV) to change brain pulsations during MREG combined with simultaneously measured respiration, continuous non-invasive blood pressure, and cortical near-infrared spectroscopy (NIRS) in healthy volunteers. Changes in classical resting-state network BOLD-like signal and cortical blood oxygenation were reproduced based on MREG and NIRS signals. Cardiovascular pulsation amplitudes of MREG signal from anterior cerebral artery, oxygenated hemoglobin concentration in frontal cortex, and blood pressure decreased after BH. MREG cardiovascular pulse amplitudes in cortical areas...
Enhanced nociceptive firing in trigeminal ganglion neurons is a likely reason for migraine pain. ... more Enhanced nociceptive firing in trigeminal ganglion neurons is a likely reason for migraine pain. In experimental migraine-like conditions induced by the calcitonin gene-related peptide (CGRP), P2X3 receptors abundantly expressed in trigeminal neurons are highly responsive to the excitatory action of extracellular ATP. In this study, we tested whether naproxen, a common antimigraine medicine, could affect the function of P2X3 receptors in the presence or absence of the algogen nerve growth factor (NGF), the level of which is elevated in patients with chronic migraine. We used calcium imaging and patch clamp recordings from rat trigeminal neurons, which were activated by a relative specific P2X3 agonist α,β-meATP or by high potassium-induced depolarization. In the absence of NGF, naproxen dose-dependently (0.1-1 mM) reduced intracellular calcium transients elicited by α,β-meATP. Naproxen also led to a slight, but significant, reduction in calcium transients induced by potassium ions, indicating the involvement of voltage-gated calcium channels. The inhibitory action of 1 mM naproxen was enhanced after NGF pretreatment, suggesting that P2X3 receptors in sensitized neurons are more susceptible to inhibition by high doses of this nonsteroidal anti-inflammatory drug (NSAID). Using patch clamp recordings from HEK293 cells expressing P2X3 receptors, we tested the direct action of naproxen on P2X3 receptor-mediated membrane currents. In clinically relevant concentrations of 0.5 mM, naproxen produced a use-dependent blocking effect on ATP receptors. Kinetic analysis suggests that naproxen inhibited P2X3 receptors via facilitation of fast desensitization, which determines current decay in the continuous presence of the agonist. In summary, we present a novel fast mechanism for the antimigraine action of naproxen, which can act in synergy with the cyclooxygenase inhibition to attenuate headaches.
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Papers by Taneli Hautaniemi