Our laboratory is trying to understand how single neurons and populations of neurons encode the information needed to plan and execute limb movements. Our goal is to decipher how the brain represents different movement parameters and then uses this information to control movements. We are investigating both kinematic and dynamic movement parameters, recording the activity of neurons in the cerebellum in primates during motor behaviors. A variety of movements are studied, including reaching to targets in space, tracking moving targets, the learning of new visuomotor relations, and hand movements. Using analytical and statistical techniques, we sort out how information about movement parameters is embedded in the neuronal discharge.
We are also interested in how information in the brain is represented spatially and temporally in populations of neurons. In the cerebellum we are using flavoprotein fluorescence and Ca 2+ dyes to visualize neural activity. We also use optogenetics to perturb the cerebellar circuit. We are able to construct detailed spatial and temporal maps of the neuronal activity in the cerebellar cortex, investigating how the cerebellar circuit functions and how synaptic plasticity modifies circuit properties. In addition, we are using these techniques to examine abnormalities in the cerebellar cortex in the spinocerebellar and episodic ataxias.
(For a comprehensive list of recent publications, refer to PubMed, a service provided by the National Library of Medicine.)
- Hedges VL, Chen G, Yu L, Krentzel AA, Starrett JR, Zhu JN, Suntharalingam P, Remage-Healey L, Wang JJ, Ebner TJ, Mermelstein PG. Local estrogen synthesis regulates parallel fiber-Purkinje cell neurotransmission within the cerebellar cortex. Endocrinology. 2018 Jan 25. doi: 10.1210/en.2018-00039.
- Chen G, Carter RE, Cleary JD, Reid TS, Ranum LP, Swanson MS, Ebner TJ. Altered levels of the splicing factor muscleblind modifies cerebral cortical function in mouse models of myotonic dystrophy. Neurobiol Dis. 2018;112:35-48.
- Streng ML, Popa LS, Ebner TJ. Climbing fibers predict movement kinematics and performance errors. J Neurophysiol. 2017;118:1888-1902
- Popa LS, Streng ML, Ebner TJ. Long-term predictive and feedback encoding of motor signals in the simple spike discharge of Purkinje cells. eNeuro. 2017 Apr;4(2). pii: ENEURO.0036-17.2017.
- Streng ML, Popa LS, Ebner TJ. Climbing fibers control Purkinje cell representations of behavior. J Neurosci. 2017;37(8):1997-2009.
- Lang EJ, Apps R, Bengtsson F, Cerminara NL, De Zeeuw CI, Ebner TJ, Heck DH, Jaeger D, Jörntell H, Kawato M, Otis TS, Ozyildirim O, Popa LS, Reeves AM, Schweighofer N, Sugihara I, Xiao J. The roles of the olivocerebellar pathway in motor learning and motor control. A consensus paper. Cerebellum. 2017;16(1):230-252.
- Popa LS, Streng ML, Hewitt AL, Ebner TJ. The errors of our ways: Understanding error representations in cerebellar-dependent motor learning. Cerebellum. 2016;15:93-103.
- Cramer SW, Popa LS, Carter RE, Chen G, Ebner TJ. Abnormal excitability and episodic low-frequency oscillations in the cerebral cortex of the tottering mouse. J Neurosci. 2015;35:5664-79.
- Popa LS, Hewitt AL, Ebner TJ. The cerebellum for jocks and nerds alike. Front Syst Neurosci. 2014 Jun 17;8:113.
- Hewitt AL, Popa LS, Ebner TJ. Changes in Purkinje cell simple spike encoding of reach kinematics during adaption to a mechanical perturbation. J Neurosci. 2015;35:1106-24.
- Prosise JF, Hendrix CM, Ebner TJ. Joint angles and angular velocities and relevance of eigenvectors during prehension in the monkey. Exp Brain Res. 2015;233:339-50.
- Armbrust KR, Wang X, Hathorn TJ, Cramer SW, Chen G, Zu T, Kangas T, Zink AN, Öz G, Ebner TJ, Ranum LP. Mutant β-III spectrin causes mGluR1α mislocalization and functional deficits in a mouse model of spinocerebellar ataxia type 5. J Neurosci. 2014;34:9891-904.
- Cramer SW, Gao W, Chen G, Ebner TJ. Reevaluation of the beam and radial hypotheses of parallel fiber action in the cerebellar cortex. J Neurosci. 2013;33:11412-11424.
- Popa LS, Hewitt AL, Ebner TJ. Predictive and feedback performance errors are signaled in the simple spike discharge of individual Purkinje cells. J Neurosci. 2012;32:15345-58.
- Barnes JA, Ebner BA, Duvick LA, Gao W, Chen G, Orr HT, Ebner TJ. Abnormalities in the climbing fiber-Purkinje cell circuitry contribute to neuronal dysfunction in ATXN2[82Q] mice. J Neurosci. 2011;31:12778-12789.
- Hewitt A, Popa L, Pasalar S, Hendrix C, Ebner TJ. Representation of limb kinematics in Purkinje cell simple spike discharge is conserved across multiple tasks. J Neurophysiol. 2011;106(5):2232-2247.
- Wang X, Chen G, Gao W, Ebner TJ. Parasagittally aligned, mGluR1-dependent patches are evoked at long latencies by parallel fiber stimulation in the mouse cerebellar cortex in vivo. J Neurophysiol 2011;105:1732-1746.
Current Graduate Students:
Sarah West (Neuroscience, University of Minnesota)
Jodi Prosise (Biomedical Engineering, University of Minnesota).
Former Graduate Students:
Martha Streng (Ph.D. 2017; Neuroscience, University of Minnesota).
Samuel Cramer (Ph.D. 2014, Neuroscience, University of Minnesota).
Angela Hewitt (Ph.D. 2013, Neuroscience, University of Minnesota).
Justin Barnes (Ph.D. 2011, Neuroscience, University of Minnesota).
Kenneth Reinert (Ph.D. 2006, Neuroscience, University of Minnesota).
Robert L. Dunbar (Ph.D. M.A., 2002, Neuroscience, University of Minnesota).
Charles Hanson (Ph.D. 2001, Neuroscience, University of Minnesota).
Jose Gomez (Ph.D. 2000, Neuroscience, University of Minnesota).
Sharad J. Shanbhag (Ph.D. 1999, Neuroscience, University of Minnesota).
Stephen Helms Tillery (Ph.D. 1994, Neuroscience, University of Minnesota).
Catherine Ojakangas (Ph.D. 1992, Neuroscience, University of Minnesota).