Molecular fMRI?

Could Molecular fMRI Revolutionise Neuroscience?

Neuroskeptic [Discover Magazine Blog] | April 20, 2016

In a new paper called Molecular fMRI, MIT researchers Benjamin B. Bartelle, Ali Barandov, and Alan Jasanoff discuss technological advances that could provide neuroscientists with new tools for mapping the brain.
Currently, one of the leading methods of measuring brain activity is functional MRI (fMRI). However, as Bartelle et al. note, it has its limitations:

Because brain activity mapping with fMRI depends on neurovascular coupling, resolution at the level of single cells is out of reach… More importantly, the cellular origins of functional imaging signals are obscured by the fact that many different cells and cell types contribute simultaneously to the observed fMRI data.

Conventional MRI does not allow for MRI imaging of dopamine release. Source: http://blogs.discovermagazine.com/neuroskeptic/2016/04/20/7653/

<more at http://blogs.discovermagazine.com/neuroskeptic/2016/04/20/7653/; related articles and links: http://www.livescience.com/45276-brain-cells-viewed-at-molecular-level.html (Brain Cells Viewed 'Talking' at Molecular Level. May 1, 2014) and http://www.jneurosci.org/content/36/15/4139 (Molecular fMRI. Benjamin B. Bartelle, Ali Barandov, and Alan Jasanoff. The Journal of Neuroscience, 13 April 2016, 36(15): 4139-4148; doi: 10.1523/JNEUROSCI.4050-15.2016. [Abstract: Comprehensive analysis of brain function depends on understanding the dynamics of diverse neural signaling processes over large tissue volumes in intact animals and humans. Most existing approaches to measuring brain signaling suffer from limited tissue penetration, poor resolution, or lack of specificity for well-defined neural events. Here we discuss a new brain activity mapping method that overcomes some of these problems by combining MRI with contrast agents sensitive to neural signaling. The goal of this “molecular fMRI” approach is to permit noninvasive whole-brain neuroimaging with specificity and resolution approaching current optical neuroimaging methods. In this article, we describe the context and need for molecular fMRI as well as the state of the technology today. We explain how major types of MRI probes work and how they can be sensitized to neurobiological processes, such as neurotransmitter release, calcium signaling, and gene expression changes. We comment both on past work in the field and on challenges and promising avenues for future development. SIGNIFICANCE STATEMENT Brain researchers currently have a choice between measuring neural activity using cellular-level recording techniques, such as electrophysiology and optical imaging, or whole-brain imaging methods, such as fMRI. Cellular level methods are precise but only address a small portion of mammalian brains; on the other hand, whole-brain neuroimaging techniques provide very little specificity for neural pathways or signaling components of interest. The molecular fMRI techniques we discuss have particular potential to combine the specificity of cellular-level measurements with the noninvasive whole-brain coverage of fMRI. On the other hand, molecular fMRI is only just getting off the ground. This article aims to offer a snapshot of the status and future prospects for development of molecular fMRI techniques.])>