April 21
@
12:00 PM
–
1:00 PM
Analyzing Brain-Wide Function Using New Molecular Imaging Tools
Alan Jasanoff, PhD
Professor of Biological Engineering and Brain and Cognitive Sciences
Massachusetts Institute of Technology
Abstract:
Behavior and cognition depend on the integrated action of neural structures and populations distributed throughout the brain. Deciphering mechanisms by which this takes this place is both a tremendous scientific problem and a major engineering challenge, because of the need to establish suitable measurement technologies. We are creating a set of molecular imaging tools that enable multiregional neural processing to be studied at a brain-wide scale in rodents and nonhuman primates. Here we will describe how a novel genetically encoded activity reporter we have engineered enables information flow in virally labeled neural circuitry to be monitored by fMRI. Using the reporter to perform functional imaging of synaptically defined cell populations in the rat somatosensory system, we show how activity is transformed within brain regions to yield characteristics specific to distinct output projections. We also show how this approach enables regional activity phenomena to be modeled in terms of inputs, in a paradigm that we are extending to address circuit-level origins of functional specialization in marmoset brains. In the second part of the talk, we will discuss how some of our MRI tools now enable the detection of optical reporters in deep neural tissue. We use novel imaging probes to detect luminescent proteins, yielding a hybrid optical/MRI noninvasive imaging modality that surpasses limitations of conventional methods. This work demonstrates the possibility of investigating diverse brain-wide processing phenomena using advanced molecular neuroimaging methods.
Print PDF