TY - JOUR
T1 - Laminar fMRI
T2 - What can the time domain tell us?
AU - Petridou, Natalia
AU - Siero, JCW
N1 - Funding Information:
This work has supported by a Netherlands Organisation for Scientific Research Vidi Grant 13339 (N?P.) and the National Institute of Mental Health of the National Institutes of Health under award number R01MH111417. The Spinoza Center is a joint initiative of the University of Amsterdam, Academic Medical Center, VU University, VU University Medical Center, Netherlands Institute for Neuroscience and the Royal Netherlands Academy of Sciences.
Funding Information:
This work has supported by a Netherlands Organisation for Scientific Research Vidi Grant 13339 (N·P.) and the National Institute of Mental Health of the National Institutes of Health under award number R01MH111417 . The Spinoza Center is a joint initiative of the University of Amsterdam, Academic Medical Center, VU University, VU University Medical Center, Netherlands Institute for Neuroscience and the Royal Netherlands Academy of Sciences.
Publisher Copyright:
© 2017 Elsevier Inc.
PY - 2019/8/15
Y1 - 2019/8/15
N2 - The rapid developments in functional MRI (fMRI) acquisition methods and hardware technologies in recent years, particularly at high field (≥7 T), have enabled unparalleled visualization of functional detail at a laminar or columnar level, bringing fMRI close to the intrinsic resolution of brain function. These advances highlight the potential of high resolution fMRI to be a valuable tool to study the fundamental processing performed in cortical micro-circuits, and their interactions such as feedforward and feedback processes. Notably, because fMRI measures neuronal activity via hemodynamics, the ultimate resolution it affords depends on the spatial specificity of hemodynamics to neuronal activity at a detailed spatial scale, and by the evolution of this specificity over time. Several laminar (≤1 mm spatial resolution) fMRI studies have examined spatial characteristics of the measured hemodynamic signals across cortical depth, in light of understanding or improving the spatial specificity of laminar fMRI. Few studies have examined temporal features of the hemodynamic response across cortical depth. Temporal features of the hemodynamic response offer an additional means to improve the specificity of fMRI, and could help target neuronal processes and neurovascular coupling relationships across laminae, for example by differences in the onset times of the response across cortical depth. In this review, we discuss factors that affect the timing of neuronal and hemodynamic responses across laminae, touching on the neuronal laminar organization, and focusing on the laminar vascular organization. We provide an overview of hemodynamics across the cortical vascular tree based on optical imaging studies, and review temporal aspects of hemodynamics that have been examined across cortical depth in high spatiotemporal resolution fMRI studies. Last, we discuss the limits and potential of high spatiotemporal resolution fMRI to study laminar neurovascular coupling and neuronal processes.
AB - The rapid developments in functional MRI (fMRI) acquisition methods and hardware technologies in recent years, particularly at high field (≥7 T), have enabled unparalleled visualization of functional detail at a laminar or columnar level, bringing fMRI close to the intrinsic resolution of brain function. These advances highlight the potential of high resolution fMRI to be a valuable tool to study the fundamental processing performed in cortical micro-circuits, and their interactions such as feedforward and feedback processes. Notably, because fMRI measures neuronal activity via hemodynamics, the ultimate resolution it affords depends on the spatial specificity of hemodynamics to neuronal activity at a detailed spatial scale, and by the evolution of this specificity over time. Several laminar (≤1 mm spatial resolution) fMRI studies have examined spatial characteristics of the measured hemodynamic signals across cortical depth, in light of understanding or improving the spatial specificity of laminar fMRI. Few studies have examined temporal features of the hemodynamic response across cortical depth. Temporal features of the hemodynamic response offer an additional means to improve the specificity of fMRI, and could help target neuronal processes and neurovascular coupling relationships across laminae, for example by differences in the onset times of the response across cortical depth. In this review, we discuss factors that affect the timing of neuronal and hemodynamic responses across laminae, touching on the neuronal laminar organization, and focusing on the laminar vascular organization. We provide an overview of hemodynamics across the cortical vascular tree based on optical imaging studies, and review temporal aspects of hemodynamics that have been examined across cortical depth in high spatiotemporal resolution fMRI studies. Last, we discuss the limits and potential of high spatiotemporal resolution fMRI to study laminar neurovascular coupling and neuronal processes.
KW - Journal Article
KW - Review
KW - Ultra-high field
KW - Laminar fMRI
KW - Spatiotemporal characteristics
KW - 7T
KW - Hemodynamic response
KW - Onset
UR - http://www.scopus.com/inward/record.url?scp=85026459582&partnerID=8YFLogxK
U2 - 10.1016/j.neuroimage.2017.07.040
DO - 10.1016/j.neuroimage.2017.07.040
M3 - Review article
C2 - 28736308
SN - 1053-8119
VL - 197
SP - 761
EP - 771
JO - NeuroImage
JF - NeuroImage
ER -