The long-term goal of this research is to determine the sites and mechanisms of motor learning in a voluntary movement system that depends heavily on inputs from the cerebral cortex and that uses the cortico-ponto-cerebellar pathways. Smooth pursuit eye movements meet these criteria and therefore afford a model system for revealing principles of motor learning that may generalize to learning of somatic movements. Under normal conditions, a moving target is needed to generate pursuit and the onset of target motion evokes and early eye acceleration at an amplitude related to target speed. Preliminary results have demonstrated that the eye acceleration in this early interval can be adapted to be larger or smaller if the target starts at one speed and, after 100ms, undergoes a step increase of decrease in speed. This learning takes about 30 minutes and is reversible and repeatable over the same time course. In this grant, one aim will use measurements of eye movements before and after learning to determine whether learning is also expressed in the response to a brief perturbation of target motion given during sustained pursuit.
A second aim will record the expression of learning in the cerebellar cortex by following the responses of individual Purkinje cells in the floccular lobe before, during, and after learning.
The third aim will use microstimulation and recording in extrastriate visual areas MT and MST. Microstimulation at an individual site before and after learning will reveal whether sites of learning are in the pathways from MT and MST to the cerebellum. Recordings will follow the responses of individual cells before, during, and after learning, to reveal whether learning can occur in the cerebral cortex.
The final aim will develop a new class of pursuit model that is based on realistic visual inputs and that can reproduce the data obtained here. The results will provide insights into the normal processes of motor learning and may provide information about how to treat and reverse motor disorders, especially those that are learned through repetitive use of the same movement.

Project Start
1998-05-01
Project End
1999-04-30
Budget Start
1997-10-01
Budget End
1998-09-30
Support Year
2
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of California San Francisco
Department
Type
DUNS #
073133571
City
San Francisco
State
CA
Country
United States
Zip Code
94143
Zhou, Xiaoming; Merzenich, Michael M (2012) Environmental noise exposure degrades normal listening processes. Nat Commun 3:843
Nagel, Katherine; Kim, Gunsoo; McLendon, Helen et al. (2011) A bird brain's view of auditory processing and perception. Hear Res 273:123-33
Zhou, Xiaoming; Merzenich, Michael M (2009) Developmentally degraded cortical temporal processing restored by training. Nat Neurosci 12:26-8
Heuer, Hilary W; Tokiyama, Stefanie; Lisberger, Stephen G (2008) Doing without learning: stimulation of the frontal eye fields and floccular complex does not instruct motor learning in smooth pursuit eye movements. J Neurophysiol 100:1320-31
de Villers-Sidani, Etienne; Simpson, Kimberly L; Lu, Y-F et al. (2008) Manipulating critical period closure across different sectors of the primary auditory cortex. Nat Neurosci 11:957-65
Nagel, Katherine I; Doupe, Allison J (2008) Organizing principles of spectro-temporal encoding in the avian primary auditory area field L. Neuron 58:938-55
Schoppik, David; Nagel, Katherine I; Lisberger, Stephen G (2008) Cortical mechanisms of smooth eye movements revealed by dynamic covariations of neural and behavioral responses. Neuron 58:248-60
Kojima, Satoshi; Doupe, Allison J (2008) Neural encoding of auditory temporal context in a songbird basal ganglia nucleus, and its independence of birds'song experience. Eur J Neurosci 27:1231-44
de Villers-Sidani, Etienne; Chang, Edward F; Bao, Shaowen et al. (2007) Critical period window for spectral tuning defined in the primary auditory cortex (A1) in the rat. J Neurosci 27:180-9
Amin, Noopur; Doupe, Allison; Theunissen, Frederic E (2007) Development of selectivity for natural sounds in the songbird auditory forebrain. J Neurophysiol 97:3517-31

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