Autofluorescence Imaging of the Cerebellar Cortex In Vivo: Properties, Functions and Cellular Origins
Systems Neuroscience Institute
University of Pittsburg, PA
- Timothy J. Ebner, M.D., Ph.D.
- Daniel Boley
My primary research interests are in learning and memory, escpecially in the cerebellar cortex. The lab I am currently working in uses optical imaging techniques to study population level dynamics of the inputs to the cerebellum, climbing fibers from the inferior olive and the mossy fiber/parallel fiber system from the pons, the interactions between them and their plasticity. My current research project focuses on examining the exact timing requirements for parallel fiber-Purkinje cell long term depression (PF-PC LTD) in the cerebellum. The result of this study will resolve a long debate among cerebellar physiologists as to the nature of cerebellar motor learning.
We have recently discovered a new imaging technique involving the use of endogenous fluorescent compounds that are intrinsic to all cells. These compounds, called flavoproteins, are part of the metabolic machinery of the cell's mitochondria. As neurons depolarize, they use signalling molecules such as calcium ions and ADP to signal a change in the energy requirements of the cell. The mitochondria detect these changes and go through a transient oxidative phase to generate the needed energy and then a reductive phase to build up stores for future use. The flavoproteins in the mitochondria fluoresce when oxidized, so we can detect this oxidative phase as an increase in fluorescence in the tissue. Thus we have a non-invasive means of recording neuronal activity at a subcellular level without the need for dyes or contrast agents (see citation below). We are currently using this technique for my LTD timing study as well as a study of the patterns of inhibition on the cerebellar cortex.
- K.C. Reinert, W. Gao, G. Chen, X. Wang, Y.P. Peng, T.J. Ebner. Cellular and Metabolic Origins of
Flavoprotein Autofluorescence in the Cerebellar Cortex In Vivo. Cerebellum. 2011 Sep;10(3):585-99.
- K.C. Reinert, W. Gao, G. Chen, T.J. Ebner. Flavoprotein Autofluorescence Imaging in the Cerebellar Cortex In Vivo. J Neurosci Res 2007 Nov 15; 85(15):3221-3232.
- W. Gao, G. Chen, K.C. Reinert, T.J. Ebner. Cerebellar cortical molecular layer inhibition is organized into parasagittal zones. J Neurosci 2006 Aug 9; 26(32):8377-8387.
- G. Chen, W. Gao, K.C. Reinert, L.S. Popa, C.M. Hendrix, M.E. Ross, T.J. Ebner. Involvement of
Kv1 potassium channels in spreading acidification and depression in the cerebellar cortex. J
Neurophysiol. 2005 Aug; 94(2):1287-98. Epub 2005 Apr 20.
- T.J. Ebner, G. Chen, W. Gao, K.C. Reinert. Optical imaging of cerebellar functional architectures: parallel fiber beams, parasagittal bands and spreading acidification. Prog Brain Res. 2005; 148:125-38.
- K.C. Reinert, R.L. Dunbar, W. Gao, G. Chen, T.J. Ebner. Flavoprotein autofluorescence imaging of neuronal activation in the cerebellar cortex in vivo. J Neurophysiol 2004 Jul; 92(1):199-211.
Epub 2004 Feb 25.
- R.L. Dunbar, G. Chen, W. Gao, K.C. Reinert, R. Feddersen, T.J. Ebner. Imaging parallel fiber and climbing fiber responses and their short-term interactions in the mouse cerebellar cortex in vivo. Neuroscience 2004; 126(1):213-27.
- W. Gao, R.L. Dunbar, G. Chen, K. Reinert, J. Oberdick, T.J. Ebner. Optical imaging of long-term depression in the mouse cerebellar cortex in vivo. J Neurosci 2003; 23:1859-1866.