Editorial: Current advances in multimodal human brain imaging and analysis across the lifespan: From mapping to state prediction

Abstract

In preclinical animal models, researchers can, within the same thin slice of tissue, probe activity within neurons [e.g., immediate early gene protein products (Mcreynolds et al., [15]; Aparicio et al., [1])], examine neurons' projections and/or synaptic innervations [e.g., tract or viral tracing (Card and Enquist, [5]; Saleeba et al., [20])] and determine neurochemical phenotypes [e.g., immunohistochemistry (Magaki et al., [14])]. Great mechanistic specificity can be achieved with preclinical approaches. In understanding the human brain, neuroimaging affords researchers the opportunity to noninvasively probe brain structure, function and connectivity, but is not without limitations. For example, the blood oxygen level-dependent (BOLD) signal in functional magnetic resonance imaging (fMRI) is a proxy for neural activation based on the displacement of deoxygenated by oxygenated hemoglobin and is not, itself, neural activity (Huettel et al., [11]). Further, diffusion-weighted imaging (DWI) and derived tractography provide inferences of white matter structure based on the diffusion of water molecules restricted by neural components and do not represent specific neuronal targets or synaptic innervations. Thus, interpretation of neuroimaging findings is greatly enhanced by known neuroanatomical and functional literature from preclinical models, and efforts to find convergence across these approaches are highly important (e.g., Folloni et al., [7]; Haber et al., [9]). Similarly, a consensus between anatomical techniques in preclinical models or post-mortem human brain (e.g., blunt and/or fiber dissection) and neuroimaging (e.g., tractography) is also significant (Wu et al., [24]; Oler et al., [17]; Pascalau et al., [19]). Despite limitations of neuroimaging, there is great potential to leverage the advantages of, and integrate distinct neuroimaging modalities to achieve a broader picture of neural dynamics and a greater mechanistic understanding of myriad developmental, affective, cognitive and clinical issues. Distinct neuroimaging modalities may reveal relationships with different dimensions of early experience providing insights into neurodevelopment.