Medical College of Georgia Animal Behavior Center
The
Medical College of Georgia Animal Behavior Center has considerable
experience testing the short-term memory and attention capabilities of
non-human primates. Testing programs are available to MCG faculty on a
collaborative basis, and they are available for contractual agreements with
pharmaceutical companies and other external research programs.
Short-term memory and attention capabilities are similar in their (1)
neuroanatomical underpinnings, (2) neurochemical regulation, and (3)
relevance to a discrete set of human diseases such as Alzheimer's Type
Dementia (ATC), attention-deficit hyperactivity disorder (ADHD), and
schizophrenia.
A wealth of behavioral data in this area has been documented using
delayed-response tasks. Elderly humans perform markedly worse than young
subjects on mnemonic facets of such tasks and are more distraction-prone
while taking the tests. ATD patients display similar, but more dramatic,
memory and attention impairment and both ADHD and schizophrenic patients
perform consistently worse on such tasks than their age-matched controls.
Delayed-response testing is a well-established means of examining
neurochemical, neuroanatomical and therapeutic aspects of ATD, ADHD and
schizophrenia. Behavioral paradigms at the Animal Behavior Center are
designed around an automated
delayed-response task assessing the function of mnemonic and attention
processes. Particularly significant is the fact that each paradigm differs
regarding the relative emphasis on these two different, yet interdependent,
cognitive constructs.
The Animal Behavior Center also is experienced in stereotaxic
implantation of intracranial electrodes and cannulas in rodents and
non-human primates.
The basic approaches and procedures of the Animal Behavior Center
include:
Delayed Matching-to-Sample (DMTS)
Testing sessions consist of 96 trials five days a week. Test panels,
attached to subjects' home cages, have disks that flash red, green and
yellow. To begin the test, a sample key is illuminated by one of the
colored lights. The sample remains illuminated until the animal responds
to the sample key. When the animal presses the key, the light disappears
and initiates one of four pre-programmed delay intervals, during which no
keys are illuminated. Then, two lights located below the sample key are
illuminated. One is the color of the original sample light; the other is a
different color. The key remains illuminated until the animal presses a
key. If he presses the matching color, he is rewarded; if not, a new trial
begins. Delays between illuminating the sample and choice lights vary from
0 to 160 seconds, depending on the skill of the animal and purpose of the
test; for instance, DMTS can test not only memory, but also attention by
varying the delay interval. Aged rhesus monkeys (20-45 years old) are
significantly impaired in DMTS performance compared with younger animals.
View how the standard
DMTS task works.
DMTS With a Distractor During the Delay Interval
During this test, a random array of flashing colored lights appears on
the test panel for a pre-programmed duration during the DMTS delay
interval to assess the animal's ability to ignore irrelevant stimuli and
retain the information needed to succeed in the test. Aged monkeys perform
more poorly on this test and are more distractable than younger monkeys. A
significant advantage of this automated distraction paradigm is that,
while performing the task, subjects are not exposed to experimenters or
other extraneous stimuli, improving experimental control. Drugs used
clinically for the treatment of ADHD significantly reverse the distractor-medicated
impairment of DMTS performance in monkeys.
DMTS With a Titrated Delay Interval
Another DMTS variation is to titrate the delay interval in response to
the monkey's ongoing ability to accurately retain and recall information.
In this test, delay intervals are not pre-programmed; the delay interval
is determined by a monkey's response to a previous trial. Intervals
following a correct match increase in duration so that highly successful
monkeys operate at longer delay intervals than less successful monkeys.
This test has the advantage, particularly in testing the effects of
chronic drug administration, of providing a very selective and sensitive
measure of a monkey's maximal performance level over time. Performance can
be measured by a single statistic, such as average length of delay
interval per session, number of trials to maximal delay and/or duration of
maximal delay interval on which performance was significantly greater than
chance.
LET'S
TEAM UP!
Do you have a need for primate testing in your research programs?
If so, we can perform these tests in cost effective manner - much less
than developing your own in-house facility.
All of our protocols have been approved by our institutional animal
assurances committee and conform to all federal standards for the physical
and psychological care and well being of non-human primates.
For more information about the Medical College Animal Behavior Center and
its capabilities, contact:
Dr. Jerry J. Buccafusco
Professor of Pharmacology and Toxicology
Department of Pharmacology and Toxicology
Medical College of Georgia
Augusta, GA 30912-2300
Phone: (706) 721-6355
FAX: (706) 721-9861
Email:
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