The overall goal of my research program is to understand the role of the basal ganglia (BG) and superior colliculus (SC) in target selection for saccadic eye movements. In this application we are focused on the relationship of one output nucleus of the BG, the substantia nigra pars reticulata (SNr) to the SC and their combined role in processing events related to choosing a goal for a saccadic eye movement. A central question in cognitive neuroscience is how visual stimuli are identified as objects for perceptual processing or as goals for movements. Historically, the cortico-BG-SC pathway is considered `passive'in the sense that it receives processed cortical information and through a series of sign changes in nuclei that inhibit their targets, provides a transient, disinhibition to the SC to initiate a saccade. In this application we propose that the BG also play an active role in decisions related to selecting where and when to make a saccade. This proposal has two specific aims;1) determine whether saccade selection results from SC neuronal activity increasing to a threshold and 2) determine whether the inhibitory output of the SNr influences neuronal processing within the SC and the evolution of saccade choice. During the last award cycle, we demonstrated that selecting a saccade resolved competition between movement goals by biasing stimulus interactions within the SC, as seen in extrastriate cortex. Based on those results and our preliminary data, we propose that saccade selection results from interactions among SC neuronal populations. Further, we propose that the BG input biases these competitive interactions. The current proposal extends our work in important ways. First, the experiments proposed here will build on the growing body of evidence suggesting motor areas play an active role in selection for perception and action. Second, the results will provide necessary and detailed information about the relationship of the SNr to the SC and how this pathway contributes to saccade choices. Furthermore, since saccadic eye movement abnormalities are a prominent symptom in a number of diseases involving the BG and cortico-BG circuits, such as Parkinson's disease, Huntington's disease, obsessive-compulsive disorder, attention deficit disorder and Tourette Syndrome, our results should provide important insights into the mechanisms of symptomology in these disease states. The overall goal of my research program is to understand the role of the basal ganglia and superior colliculus in target selection for saccadic (rapid) eye movements. In this application we focus on understanding the relationship of one output nucleus of the basal ganglia and its target structure, the superior colliculus and their combined role in processing events related to choosing a goal for a saccadic eye movement. Because saccadic eye movement abnormalities are a prominent symptom in a number of diseases involving the basal ganglia and cortico-basal ganglia circuits, such as Parkinson's disease, Huntington's disease, obsessive-compulsive disorder, attention deficit disorder and Tourette Syndrome, we expect our results to provide important insights into the underlying physiological mechanisms of symptoms seen in these disease states.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY013692-10
Application #
8265286
Study Section
Central Visual Processing Study Section (CVP)
Program Officer
Steinmetz, Michael A
Project Start
2001-12-01
Project End
2014-05-31
Budget Start
2012-06-01
Budget End
2014-05-31
Support Year
10
Fiscal Year
2012
Total Cost
$356,662
Indirect Cost
$119,062
Name
University of California Los Angeles
Department
Psychiatry
Type
Schools of Medicine
DUNS #
092530369
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Basso, M A; Sommer, M A (2011) Exploring the role of the substantia nigra pars reticulata in eye movements. Neuroscience 198:205-12
Kim, Byounghoon; Basso, Michele A (2010) A probabilistic strategy for understanding action selection. J Neurosci 30:2340-55
Shires, Joel; Joshi, Siddhartha; Basso, Michele A (2010) Shedding new light on the role of the basal ganglia-superior colliculus pathway in eye movements. Curr Opin Neurobiol 20:717-25
Gooding, Diane C; Basso, Michele A (2008) The tell-tale tasks: a review of saccadic research in psychiatric patient populations. Brain Cogn 68:371-90
Wark, H A C; Garell, P C; Walker, A L et al. (2008) A case report on fixation instability in Parkinson's disease with bilateral deep brain stimulation implants. J Neurol Neurosurg Psychiatry 79:443-7
Li, Xiaobing; Kim, Byounghoon; Basso, Michele A (2006) Transient pauses in delay-period activity of superior colliculus neurons. J Neurophysiol 95:2252-64
Smith, Joshua J; Hadzic, Vezira; Li, Xiaobing et al. (2006) Objective measures of health and well-being in laboratory rhesus monkeys (Macaca mulatta). J Med Primatol 35:388-96
Williamson, Shawn S; Zivotofsky, Ari Z; Basso, Michele A (2005) Modulation of gaze-evoked blinks depends primarily on extraretinal factors. J Neurophysiol 93:627-32
Basso, Michele A; Pokorny, Jennifer J; Liu, Ping (2005) Activity of substantia nigra pars reticulata neurons during smooth pursuit eye movements in monkeys. Eur J Neurosci 22:448-64
Li, Xiaobing; Basso, Michele A (2005) Competitive stimulus interactions within single response fields of superior colliculus neurons. J Neurosci 25:11357-73