Functional development of the olfactory system in the developing rat



The objective of this project is to characterize functional changes in the rat olfactory system during normal and disrupted postnatal development using high-resolution MRI techniques. The techniques we plan to use include manganese-enhanced MRI, fMRI and DTI. Preliminary findings have been reported as an abstract.

Collaborators: Marla Luskin

____________________________________________

Manganese-enhanced MRI of olfactory pathway after fear conditioning



Manganese Enhanced MRI is a relatively new area of research which uses manganese to trace complex neural pathways. Manganese is a calcium analogue taken up by activated neurons and transported transynaptically; manganese also shortens the MRI T1 relaxation time wherever present.  We are interested in the olfactory neural network of mice, specifically manganese transport dependence upon controlled variables in this system.  3-D T1 weighted anatomical scans of mice which have been nasally injected with manganese will be collected for normal mice, odor conditioned mice, and mice which have been fear conditioned with a specific odor. Analysis methods will be implemented to determine alterations in transport due to odor administration and fear conditioning.

Collaborators: Michael Davis, Kerry Ressler, Seth Jones (Emory Psychiatry Department)


____________________________________________

Social network analysis of functional connectivity



One of the challenges of mapping functional connectivity with fMRI lies in interpreting large amounts of data. We are developing social network analysis techniques to identify groups of strongly correlated pixels and to define the relationship between different groups. Ideally this will extract maximal information from the data and display it in a easily understood manner.


____________________________________________

MRSI for glioma treatment planning and evaluation



Gliomas account for over half of primary brain tumors in adults, most of which are high grade with median survival times of 6-24 months. Target delineation is difficult because of spatial heterogeneity, complicated infiltration patterns, and poorly defined margins on conventional MR and CT images. Within a tumor may also be areas with markedly different biologic and metabolic characteristics. Current treatment planning ignores biologic information about extent and degree of malignancy of tumor. Specialized techniques such as magnetic resonance spectroscopic imaging (MRSI) and diffusion tensor imaging (DTI) can provide information about tumor activity and infiltration based upon the levels of cellular metabolites and tumor microstructure. Our collaboration with Emory Radiation Oncology is creating software that will incorporate findings from these methods to better guide dose prescription and to evaluate tumor response. Statistical techniques evaluating biologic and metabolic characteristics before and after tumor treatment are being developed to quantitatively describe tumor progression.

Collaborators: Tim Fox, Ian Crocker, Hui-Kuo Shu (Radiation Oncology)


____________________________________________