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The subcortical cocktail problem; mixed signals from the subthalamic nucleus and substantia nigra.

de Hollander G, Keuken MC, Forstmann BU - PLoS ONE (2015)

Bottom Line: The subthalamic nucleus and the directly adjacent substantia nigra are small and important structures in the basal ganglia.Functional magnetic resonance imaging studies have shown that the subthalamic nucleus and substantia nigra are selectively involved in response inhibition, conflict processing, and adjusting global and selective response thresholds.Here, we investigated the consistency in localization of these nuclei in BOLD fMRI studies, comparing reported coordinates with probabilistic atlas maps of young human participants derived from ultra-high resolution 7T MRI scanning.

View Article: PubMed Central - PubMed

Affiliation: Amsterdam Brain & Cognition Center, University of Amsterdam, Amsterdam, Netherlands.

ABSTRACT
The subthalamic nucleus and the directly adjacent substantia nigra are small and important structures in the basal ganglia. Functional magnetic resonance imaging studies have shown that the subthalamic nucleus and substantia nigra are selectively involved in response inhibition, conflict processing, and adjusting global and selective response thresholds. However, imaging these nuclei is complex, because they are in such close proximity, they can vary in location, and are very small relative to the resolution of most fMRI sequences. Here, we investigated the consistency in localization of these nuclei in BOLD fMRI studies, comparing reported coordinates with probabilistic atlas maps of young human participants derived from ultra-high resolution 7T MRI scanning. We show that the fMRI signal reported in previous studies is likely not unequivocally arising from the subthalamic nucleus but represents a mixture of subthalamic nucleus, substantia nigra, and surrounding tissue. Using a simulation study, we also tested to what extent spatial smoothing, often used in fMRI preprocessing pipelines, influences the mixture of BOLD signals. We propose concrete steps how to analyze fMRI BOLD data to allow inferences about the functional role of small subcortical nuclei like the subthalamic nucleus and substantia nigra.

No MeSH data available.


Location of individual peak coordinates of the STN and SN.Coronal slices in anterior to posterior direction are displayed together with functional coordinates of the STN, SN, SN/VTA, and SN/STN as reported in Table 1. Overlaid onto these coordinates is the probabilistic atlas of the STN and SN. The isolines reflect the percentage overlap across the 30 young subjects taken from Keuken et al. [28]. The outermost isolines reflects a 10% probability of containing the SN at the population level, the more inner lines represent 30%, 50%, and 70% probability of containing the SN. The outermost isolines for the STN reflects a probability of 20% containing the STN, the inner line represent 40% probability of containing the STN. The grid size corresponds to a voxel size of 3x3 mm. All coordinates are in MNI standard space.
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pone.0120572.g001: Location of individual peak coordinates of the STN and SN.Coronal slices in anterior to posterior direction are displayed together with functional coordinates of the STN, SN, SN/VTA, and SN/STN as reported in Table 1. Overlaid onto these coordinates is the probabilistic atlas of the STN and SN. The isolines reflect the percentage overlap across the 30 young subjects taken from Keuken et al. [28]. The outermost isolines reflects a 10% probability of containing the SN at the population level, the more inner lines represent 30%, 50%, and 70% probability of containing the SN. The outermost isolines for the STN reflects a probability of 20% containing the STN, the inner line represent 40% probability of containing the STN. The grid size corresponds to a voxel size of 3x3 mm. All coordinates are in MNI standard space.

Mentions: ±: coordinates not displayed in Fig. 1. The age is given in the mean years if provided, otherwise the range is given. N.S. not specified.


The subcortical cocktail problem; mixed signals from the subthalamic nucleus and substantia nigra.

de Hollander G, Keuken MC, Forstmann BU - PLoS ONE (2015)

Location of individual peak coordinates of the STN and SN.Coronal slices in anterior to posterior direction are displayed together with functional coordinates of the STN, SN, SN/VTA, and SN/STN as reported in Table 1. Overlaid onto these coordinates is the probabilistic atlas of the STN and SN. The isolines reflect the percentage overlap across the 30 young subjects taken from Keuken et al. [28]. The outermost isolines reflects a 10% probability of containing the SN at the population level, the more inner lines represent 30%, 50%, and 70% probability of containing the SN. The outermost isolines for the STN reflects a probability of 20% containing the STN, the inner line represent 40% probability of containing the STN. The grid size corresponds to a voxel size of 3x3 mm. All coordinates are in MNI standard space.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4368736&req=5

pone.0120572.g001: Location of individual peak coordinates of the STN and SN.Coronal slices in anterior to posterior direction are displayed together with functional coordinates of the STN, SN, SN/VTA, and SN/STN as reported in Table 1. Overlaid onto these coordinates is the probabilistic atlas of the STN and SN. The isolines reflect the percentage overlap across the 30 young subjects taken from Keuken et al. [28]. The outermost isolines reflects a 10% probability of containing the SN at the population level, the more inner lines represent 30%, 50%, and 70% probability of containing the SN. The outermost isolines for the STN reflects a probability of 20% containing the STN, the inner line represent 40% probability of containing the STN. The grid size corresponds to a voxel size of 3x3 mm. All coordinates are in MNI standard space.
Mentions: ±: coordinates not displayed in Fig. 1. The age is given in the mean years if provided, otherwise the range is given. N.S. not specified.

Bottom Line: The subthalamic nucleus and the directly adjacent substantia nigra are small and important structures in the basal ganglia.Functional magnetic resonance imaging studies have shown that the subthalamic nucleus and substantia nigra are selectively involved in response inhibition, conflict processing, and adjusting global and selective response thresholds.Here, we investigated the consistency in localization of these nuclei in BOLD fMRI studies, comparing reported coordinates with probabilistic atlas maps of young human participants derived from ultra-high resolution 7T MRI scanning.

View Article: PubMed Central - PubMed

Affiliation: Amsterdam Brain & Cognition Center, University of Amsterdam, Amsterdam, Netherlands.

ABSTRACT
The subthalamic nucleus and the directly adjacent substantia nigra are small and important structures in the basal ganglia. Functional magnetic resonance imaging studies have shown that the subthalamic nucleus and substantia nigra are selectively involved in response inhibition, conflict processing, and adjusting global and selective response thresholds. However, imaging these nuclei is complex, because they are in such close proximity, they can vary in location, and are very small relative to the resolution of most fMRI sequences. Here, we investigated the consistency in localization of these nuclei in BOLD fMRI studies, comparing reported coordinates with probabilistic atlas maps of young human participants derived from ultra-high resolution 7T MRI scanning. We show that the fMRI signal reported in previous studies is likely not unequivocally arising from the subthalamic nucleus but represents a mixture of subthalamic nucleus, substantia nigra, and surrounding tissue. Using a simulation study, we also tested to what extent spatial smoothing, often used in fMRI preprocessing pipelines, influences the mixture of BOLD signals. We propose concrete steps how to analyze fMRI BOLD data to allow inferences about the functional role of small subcortical nuclei like the subthalamic nucleus and substantia nigra.

No MeSH data available.