Timothy J. Ebner, MD, PhD
Head, Department of Neuroscience
Professor, Department of Neuroscience
Max E. and Mary LaDue Pickworth Endowed Chair in Neuroscience
Neurophysiology of cerebellum and motor cortex.
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 and cerebral cortex 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.
At a higher level of integration, we are 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++ dyes to visualize neural activity. Using epifluorescence and multi-photon imaging, we are able to construct detailed spatial and temporal maps of the neuronal activity in the cerebellar cortex. One major question is to understand the spatial patterns of activity generated during behavior. We are also using optical imaging to examine the abnormalities in the cerebellar cortex in the spinocerebellar and episodic ataxias.
For a list of publications, see PubMed.
- Ebner BA, Ingram MA, Barnes JA, Duvick LA, Frisch JL, H Clark B, et al. Purkinje cell ataxin-1 modulates climbing fiber synaptic input in developing and adult mouse cerebellum. J Neurosci. 2013;33(13):5806-20.
- Popa LS, Hewitt AL, Ebner TJ. Purkinje cell simple spike discharge encodes error signals consistent with a forward internal model. Cerebellum. 2013;12(3):331-3.
- 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(28):11412-24.
- Hedges VL, Ebner TJ, Meisel RL, Mermelstein PG. The cerebellum as a target for estrogen action. Front Neuroendocrinol. 2012;33(4):403-11.
- 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(44):15345-58.
- 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(4):1732-46.
- Ebner TJ, Hewitt AL, Popa LS. What features of limb movements are encoded in the discharge of cerebellar neurons? Cerebellum. 2011;10(4):683-93.
- Barnes JA, Ebner BA, Duvick LA, Gao W, Chen G, Orr HT, et al. Abnormalities in the climbing fiber-Purkinje cell circuitry contribute to neuronal dysfunction in ATXN1[82Q] mice. J Neurosci. 2011;31(36):12778-89.
- Hewitt AL, Popa LS, Pasalar S, Hendrix CM, Ebner TJ. Representation of limb kinematics in Purkinje cell simple spike discharge is conserved across multiple tasks. J Neurophysiol. 2011;106(5):2232-47.
Ranum LP, Daughters RS, Tuttle DL, Gao W, Ikeda Y, Moseley ML, et al. Double the trouble: bidirectional expression of the SCA8 CAG/CTG expansion mutation - evidence for RNA and protein gain of function effects. Rinsho Shinkeigaku. 2010;50(11):982-3.
- Roitman AV, Pasalar S, Ebner TJ. Single trial coupling of Purkinje cell activity to speed and error signals during circular manual tracking. Exp Brain Res. 2009;192(2):241-51.
- Wang X, Chen G, Gao W, Ebner T. Long-term potentiation of the responses to parallel fiber stimulation in mouse cerebellar cortex in vivo. Neuroscience. 2009;162(3):713-22.
- Ebner TJ, Hendrix CM, Pasalar S. Past, present, and emerging principles in the neural encoding of movement. Adv Exp Med Biol. 2009;629:127-37.
- Hendrix CM, Mason CR, Ebner TJ. Signaling of grasp dimension and grasp force in dorsal premotor cortex and primary motor cortex neurons during reach to grasp in the monkey.J Neurophysiol. 2009;102(1):132-45.
- Daughters RS, Tuttle DL, Gao W, Ikeda Y, Moseley ML, Ebner TJ, et al. RNA gain-of-function in spinocerebellar ataxia type 8. PLoS Genet. 2009;5(8):e1000600.
- Reinert KC, Gao W, Chen G, Ebner TJ. Flavoprotein autofluorescence imaging in the cerebellar cortex in vivo. J Neurosci Res. 2007;85(15):3221-32.
- Moseley ML, Zu T, Ikeda Y, Gao W, Mosemiller AK, Daughters RS, et al. Bidirectional expression of CUG and CAG expansion transcripts and intranuclear polyglutamine inclusions in spinocerebellar ataxia type 8. Nat Genet. 2006;38(7):758-69.
- MacNabb C, Schmitt L, Michlin M, Harris I, Thomas L, Chittendon D, et al. Neuroscience in middle schools: a professional development and resource program that models inquiry-based strategies and engages teachers in classroom implementation. CBE Life Sci Educ. 2006;5(2):144-57.
- Mason CR, Hendrix CM, Ebner TJ. Purkinje cells signal hand shape and grasp force during reach-to-grasp in the monkey. J Neurophysiol. 2006;95(1):144-58.
- Theverapperuma LS, Hendrix CM, Mason CR, Ebner TJ. Finger movements during reach-to-grasp in the monkey: amplitude scaling of a temporal synergy. Exp Brain Res. 2006;169(4):433-48.
- Gao W, Chen G, Reinert KC, Ebner TJ. Cerebellar cortical molecular layer inhibition is organized in parasagittal zones. J Neurosci. 2006;26(32):8377-87.
- Pasalar S, Roitman AV, Durfee WK, Ebner TJ. Force field effects on cerebellar Purkinje cell discharge with implications for internal models. Nat Neurosci. 2006;9(11):1404-11.
Pasalar S, Roitman AV, Ebner TJ. Effects of speeds and force fields on submovements during circular manual tracking in humans. Exp Brain Res. 2005;163(2):214-25.
- Chen G, Gao W, Reinert KC, Popa LS, Hendrix CM, M Ross E, et al. Involvement of kv1 potassium channels in spreading acidification and depression in the cerebellar cortex. J Neurophysiol. 2005;94(2):1287-98.
- Roitman AV, Pasalar S, Johnson MT, Ebner TJ. Position, direction of movement, and speed tuning of cerebellar Purkinje cells during circular manual tracking in monkey. J Neurosci. 2005;25(40):9244-57.
- Ebner TJ, Chen G, Gao W, Reinert K. Optical imaging of cerebellar functional architectures: parallel fiber beams, parasagittal bands and spreading acidification. Prog Brain Res. 2005;148:125-38.
Dunbar RL, Chen G, Gao W, Reinert KC, Feddersen R, Ebner TJ. 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.
- Maschke M, Gomez CM, Ebner TJ, Konczak J. Hereditary cerebellar ataxia progressively impairs force adaptation during goal-directed arm movements. J Neurophysiol. 2004;91(1):230-8.
- Roitman AV, Massaquoi SG, Takahashi K, Ebner TJ. Kinematic analysis of manual tracking in monkeys: characterization of movement intermittencies during a circular tracking task. J Neurophysiol. 2004;91(2):901-11.
- Mason CR, Theverapperuma LS, Hendrix CM, Ebner TJ. Monkey hand postural synergies during reach-to-grasp in the absence of vision of the hand and object. J Neurophysiol. 2004;91(6):2826-37.
- Reinert KC, Dunbar RL, Gao W, Chen G, Ebner TJ. Flavoprotein autofluorescence imaging of neuronal activation in the cerebellar cortex in vivo. J Neurophysiol. 2004;92(1):199-211.
Eriksen SK, Tuite PJ, Maxwell RE, Sullivan M, Low WC, Ebner TJ. Bilateral subthalamic nucleus stimulation for the treatment of Parkinson's disease: results of six patients. J Neurosci Nurs. 2003;35(4):223-31.
- Gao W, Dunbar RL, Chen G, Reinert KC, Oberdick J, Ebner TJ. Optical imaging of long-term depression in the mouse cerebellar cortex in vivo. J Neurosci. 2003;23(5):1859-66.
- Ebner TJ, Chen G. Spreading acidification and depression in the cerebellar cortex.Neuroscientist. 2003;9(1):37-45.
Mason CR, Gomez JE, Ebner TJ. Primary motor cortex neuronal discharge during reach-to-grasp: controlling the hand as a unit. Arch Ital Biol. 2002;140(3):229-36.
- Ebner TJ, Johnson MT, Roitman A, Fu Q. What do complex spikes signal about limb movements? Ann N Y Acad Sci. 2002;978:205-18.
- Mason CR, Gomez JE, Ebner TJ. Hand synergies during reach-to-grasp. J Neurophysiol. 2001;86(6):2896-910.
- Johnson MT, Mason CR, Ebner TJ. Central processes for the multiparametric control of arm movements in primates. Curr Opin Neurobiol. 2001;11(6):684-8.
- Chen G, Dunbar RL, Gao W, Ebner TJ. Role of calcium, glutamate neurotransmission, and nitric oxide in spreading acidification and depression in the cerebellar cortex. J Neurosci. 2001;21(24):9877-87.
Coltz JD, Johnson MT, Ebner TJ. Population code for tracking velocity based on cerebellar Purkinje cell simple spike firing in monkeys. Neurosci Lett. 2000;296(1):1-4.
- Hanson CL, Chen G, Ebner TJ. Role of climbing fibers in determining the spatial patterns of activation in the cerebellar cortex to peripheral stimulation: an optical imaging study.Neuroscience. 2000;96(2):317-31.
- Johnson MT, Ebner TJ. Processing of multiple kinematic signals in the cerebellum and motor cortices. Brain Res Brain Res Rev. 2000;33(2-3):155-68.
- Gomez JE, Fu Q, Flament D, Ebner TJ. Representation of accuracy in the dorsal premotor cortex. Eur J Neurosci. 2000;12(10):3748-60.
Johnson MT, Coltz JD, Ebner TJ. Encoding of target direction and speed during visual instruction and arm tracking in dorsal premotor and primary motor cortical neurons. Eur J Neurosci. 1999;11(12):4433-45.
- Yang G, Chen G, Ebner TJ, Iadecola C. Nitric oxide is the predominant mediator of cerebellar hyperemia during somatosensory activation in rats. Am J Physiol. 1999;277(6 Pt 2):R1760-70.
- Johnson MT, Coltz JD, Hagen MC, Ebner TJ. Visuomotor processing as reflected in the directional discharge of premotor and primary motor cortex neurons. J Neurophysiol. 1999;81(2):875-94.
- Coltz JD, Johnson MT, Ebner TJ. Cerebellar Purkinje cell simple spike discharge encodes movement velocity in primates during visuomotor arm tracking. J Neurosci. 1999;19(5):1782-803.
- Chen G, Hanson CL, Dunbar RL, Ebner TJ. Novel form of spreading acidification and depression in the cerebellar cortex demonstrated by neutral red optical imaging. J Neurophysiol. 1999;81(4):1992-8.
Chen G, Hanson CL, Ebner TJ. Optical responses evoked by cerebellar surface stimulation in vivo using neutral red. Neuroscience. 1998;84(3):645-68.