What the brain stem tells the frontal cortex. I. Oculomotor signals sent from superior colliculus to frontal eye field via mediodorsal thalamus.

Sommer, Marc A

Wurtz, Robert H

United States

2016-03-25T03:12:34Z

2004-03

Neuronal processing in cerebral cortex and signal transmission from cortex to brain stem have been studied extensively, but little is known about the numerous feedback pathways that ascend from brain stem to cortex. In this study, we characterized the signals conveyed through an ascending pathway coursing from the superior colliculus (SC) to the frontal eye field (FEF) via mediodorsal thalamus (MD). Using antidromic and orthodromic stimulation, we identified SC source neurons, MD relay neurons, and FEF recipient neurons of the pathway in Macaca mulatta. The monkeys performed oculomotor tasks, including delayed-saccade tasks, that permitted analysis of signals such as visual activity, delay activity, and presaccadic activity. We found that the SC sends all of these signals into the pathway with no output selectivity, i.e., the signals leaving the SC resembled those found generally within the SC. Visual activity arrived in FEF too late to contribute to short-latency visual responses there, and delay activity was largely filtered out in MD. Presaccadic activity, however, seemed critical because it traveled essentially unchanged from SC to FEF. Signal transmission in the pathway was fast ( approximately 2 ms from SC to FEF) and topographically organized (SC neurons drove MD and FEF neurons having similarly eccentric visual and movement fields). Our analysis of identified neurons in one pathway from brain stem to frontal cortex thus demonstrates that multiple signals are sent from SC to FEF with presaccadic activity being prominent. We hypothesize that a major signal conveyed by the pathway is corollary discharge information about the vector of impending saccades.

https://www.ncbi.nlm.nih.gov/pubmed/14573558

00738.2003

0022-3077

https://hdl.handle.net/10161/11745

eng

American Physiological Society

J Neurophysiol

10.1152/jn.00738.2003

Animals

Blinking

Brain Stem

Electric Stimulation

Electrodes

Electrophysiology

Feedback

Fixation, Ocular

Frontal Lobe

Macaca mulatta

Mediodorsal Thalamic Nucleus

Neurons

Photic Stimulation

Psychomotor Performance

Saccades

Superior Colliculi

Visual Fields

Visual Pathways

What the brain stem tells the frontal cortex. I. Oculomotor signals sent from superior colliculus to frontal eye field via mediodorsal thalamus.

Journal article

Sommer, Marc A|0000-0001-5061-763X

https://www.ncbi.nlm.nih.gov/pubmed/14573558

1381

1402

3

Basic Science Departments

Biomedical Engineering

Center for Cognitive Neuroscience

Duke

Duke Institute for Brain Sciences

Institutes and Provost's Academic Units

Neurobiology

Pratt School of Engineering

School of Medicine

University Institutes and Centers

Published

91