title: Noise and non-neuronal contributions to the BOLD signal: applications to and insights from animal studies.
abstract: The BOLD signal reflects hemodynamic events within the brain, which in turn are driven by metabolic changes and neural activity. However, the link between BOLD changes and neural activity is indirect and can be influenced by a number of non-neuronal processes. Motion and physiological cycles have long been known to affect the BOLD signal and are present in both humans and animal models. Differences in physiological baseline can also contribute to intra- and inter-subject variability. The use of anesthesia, common in animal studies, alters neural activity, vascular tone, and neurovascular coupling. Most intriguing, perhaps, are the contributions from other processes that do not appear to be neural in origin but which may provide information about other aspects of neurophysiology. This review discusses different types of noise and non-neuronal contributors to the BOLD signal, sources of variability for animal studies, and insights to be gained from animal models.
authors.affiliation: Wallace H. Coulter Department of Biomedical Engineering, Emory University/Georgia Institute of Technology, Atlanta, GA, United States; Neuroscience Program, Emory University, Atlanta, GA, United States. Electronic address: shella.keilholz@bme.gatech.edu.
authors.forename: Shella D
authors.initials: SD
authors.lastname: Keilholz
authors.affiliation: Wallace H. Coulter Department of Biomedical Engineering, Emory University/Georgia Institute of Technology, Atlanta, GA, United States.
authors.forename: Wen-Ju
authors.initials: WJ
authors.lastname: Pan
authors.affiliation: Neuroscience Program, Emory University, Atlanta, GA, United States.
authors.forename: Jacob
authors.initials: J
authors.lastname: Billings
authors.affiliation: Wallace H. Coulter Department of Biomedical Engineering, Emory University/Georgia Institute of Technology, Atlanta, GA, United States.
authors.forename: Maysam
authors.initials: M
authors.lastname: Nezafati
authors.affiliation: Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA, United States.
authors.forename: Sadia
authors.initials: S
authors.lastname: Shakil
mesh_terms: D000758:Anesthesia; D000818:Animals; D059907:Functional Neuroimaging / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D023421:Models, Animal
keywords: Animal studies; Functional MRI; Functional connectivity; Noise; Non-neuronal contributions; fMRI; rs-fMRI