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"Exposing the truth to wipe
out animal experimentation"
Government Grants Promoting Cruelty to Animals
Smith - Kettlewell Eye Research Institute, San Francisco, CA
ROBERT M. MCPEEK - Primate Testing - 2006
|Grant Number: 5R01EY014885-04
Project Title: Cortical & Subcortical Control of Saccades
PI Information: ROBERT M. MCPEEK,
Abstract: DESCRIPTION (provided by applicant): To survive,
animals must orient toward important stimuli while ignoring
irrelevant ones. Our long-term goal is to understand how the
brain selects targets for visual orienting, including saccadic
eye movements and shifts of attention without eye movements.
Saccade target selection lies at the interface between sensory
and motor systems. This project probes the functions of two
structures traditionally regarded as motor areas: the superior colliculus (SC), a subcortical region important for saccades,
and the frontal eye field (FEF), an anatomically connected
cortical region. Activity correlated with target selection has
been observed in both areas. However, it is still debatable,
particularly for the SC, whether these areas are involved in
selecting where to look, or simply receive selection-related
activity in preparation for generating a movement. We will test
the hypothesis that these areas play functional roles in target
selection by temporarily inactivating small regions of either
the SC or FEF and testing performance in tasks that distinguish
purely sensory or motor deficits from deficits in target
selection. Comparisons will reveal how the two structures differ
from each other in their contributions to target selection (Aim
1). We will also study the interactions of the SC and the FEF.
It is usually assumed that the SC is under the control of
cortical regions such as FEF, even though anatomical pathways
also lead from the SC back to the FEF. We will test the
hypothesis that SC activity influences target selection in the
FEF, using single-unit recording and inactivation. This will
reveal whether the two areas interact primarily in a
feed-forward manner, or whether feedback from the SC influences
cortical target selection (Aim 2). Evidence suggests that some
of the same brain areas control both eye movements and attention
shifts. We will test this hypothesis by investigating the
consequences of temporarily disrupting activity in the SC or FEF
on tasks requiring shifts of focal attention (Aim 3). These
experiments will help to reveal the architecture of the visual
orienting system, leading to a better understanding of human
neurological syndromes that disrupt eye movements and attention.
attention, cerebral cortex, neural information processing,
neurophysiology, orientation, saccade, superior colliculus,
brain electrical activity, central neural pathway /tract, visual
Macaca mulatta, electronic recording system, histology
Institution: SMITH-KETTLEWELL EYE RESEARCH INSTITUTE
SAN FRANCISCO, CA 94115
Fiscal Year: 2006
Project Start: 01-AUG-2003
Project End: 31-AUG-2007
ICD: NATIONAL EYE INSTITUTE
J Neurophysiol 88: 2019-2034, 2002;
The Journal of Neurophysiology Vol. 88 No. 4 October 2002, pp.
Copyright ©2002 by the American Physiological Society
Saccade Target Selection in the Superior Colliculus During a
Visual Search Task
Robert M. McPeek and Edward L. Keller
The Smith-Kettlewell Eye Research Institute, San Francisco,
A scleral eye coil and a head-holder system were implanted under
isofluorane anesthesia and aseptic surgical conditions.
Anesthesia was induced with an intramuscular injection of
ketamine. Heart rate, blood pressure, respiratory rate, and body
temperature were monitored for the duration of the surgery. A
coil made of four turns of Teflon-coated stainless-steel wire
was implanted under the conjunctiva of one eye using the
procedure described by Fuchs and Robinson (1966) as modified by
Judge et al. (1980) . At the completion of the surgery, animals
were returned to their home cages. After 2-3 mo of training in
behavioral tasks, described in the following text, the monkeys
were prepared for chronic single-unit recording in a second
aseptic surgery. A stainless steel recording chamber (12 mm ID),
tilted 38° posterior from vertical, was positioned above a
craniotomy centered on the midline. Antibiotics (Cefazolin) and
analgesics (Buprenex) were administered as needed during the
recovery period under the direction of a veterinarian.
We used standard methods to record single neurons in the
superior colliculi of three rhesus monkeys. Neural activity was
recorded using tungsten microelectrodes with impedances ranging
from 0.8 to 2.5 M at 1 kHz lowered into the brain by a hydraulic
microdrive. The microelectrode signal was amplified, band-pass
filtered, and displayed on a digital storage oscilloscope.
Action potentials were discriminated and converted into TTL
pulses using a time-amplitude window discriminator. The computer
data-acquisition system registered the occurrence of spikes with
a resolution of 1 kHz, and the neural data were stored in
register with the behavioral measurements.
Testing was performed in a dimly illuminated room. Data
collection and storage were controlled by a custom real-time
program running on a PC. Eye position and velocity were sampled
at 1 kHz and digitally stored on disk. A Macintosh computer,
which was interfaced with the PC, generated the visual displays
with software constructed using the Video Toolbox library (Pelli
1997 ). Visual stimuli were presented on a 29-in color CRT (Viewsonic
GA29) in synchronization with the monitor's vertical refresh.
The monitor had a spatial resolution of 800 × 600 pixels and a
noninterlaced refresh rate of 75 Hz. The monitor was positioned
33 cm in front of the monkey and allowed stimuli to be presented
in a field of view of approximately ±32° along the horizontal
meridian and ±30° along the vertical meridian.
The monkeys were seated in a primate chair with their heads
restrained for the duration of the testing sessions. They
executed behavioral tasks for liquid reward and were allowed to
work to satiation. Records of each animal's weight and health
status were kept, and supplemental water was given as necessary.
The animals typically worked for 5 days and were allowed free
access to water on weekends.
Please email: ROBERT M. MCPEEK,
[email protected] to protest the inhumane use of animals in this
experiment. We would also love to know about your efforts with this
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Rats, mice, birds, amphibians and other animals have
been excluded from coverage by the Animal Welfare Act. Therefore research
facility reports do not include these animals. As a result of this
situation, a blank report, or one with few animals listed, does not mean
that a facility has not performed experiments on non-reportable animals. A
blank form does mean that the facility in question has not used covered
animals (primates, dogs, cats, rabbits, guinea pigs, hamsters, pigs,
sheep, goats, etc.). Rats and mice alone are believed to comprise over 90%
of the animals used in experimentation. Therefore the majority of animals
used at research facilities are not even counted.