@article{bbd892591afb4d6db7cb12b02c83d7ee,
title = "Neuropeptide-Y both improves and impairs delayed matching-to-sample performance in rats",
abstract = "Neuropeptide-Y (NPY) was administered intracerebroventricularly to rats performing on delayed matching-to-sample (DMTS) to determine if NPY modulates short-term (working) memory. Rats administered saline demonstrated a characteristic DMTS delay gradient in which accuracy decreased as the delay interval between sample and comparison stimuli increased from 2 to 8 to 16 seconds. At 8- and 16-second delays, low doses of NPY (0.25 and 0.5 nmol/kg) increased matching accuracy. As doses increased from 1 to 16 nmol/kg, accuracy decreased in a dose- and delay-dependent manner. NPY effects were specific to working memory, since NPY did not affect accuracy of responses to the sample stimulus (reference memory). At higher doses, a greater decline in accuracy occured when the correct stimulus was on the opposite side from the response on the previous trial compared to accuracy when the previous response was on the same side. These data show NPY may both improve and impair accuracy on DMTS and that some portion of impairment is due to proactive interference resulting from previous trials.",
keywords = "Matching-to-sample, Memory modulation, NPY, Neuropeptide-Y, Proactive interference, Rats, Reference memory, Short-term memory, Working memory",
author = "Thomas, {John R.} and Ahlers, {Stephen T.}",
note = "Funding Information: As the research on memory modulation by NPY has focussed on long-term memory processes, the aim of the present study was to examine the effects of NPY on short-term or working memory. The highest concentrations of NPY and NPY receptors are in the hippocampus (6, 18, 25), a structure demonstrated to be important in working memory (10, 27, 28). In the present study, the effects of NPY on working memory were measured using a delayed matching-to-sample (DMTS) procedure in which rats were initially presented a sample stimulus and then, after varying delay intervals, required to correctly choose the sample stimulus from two comparison stimuli. In this task, a decline in accuracy is usually obtained as the delay interval between the sample and choice is lengthened, and the slope of the delay function is indicative of the rate of forgetting from working memory (22, 31, 32). The DMTS paradigm developed for rats in our laboratory is similar to others (5, 10, 11, 22), with the important addition that reference memory is also measured on each trial along with working memory (2,38). At the start of each matching trial, one of two lights located over each of two levers is illuminated as the sample stimulus. The animal is re- ~Experiments reported herein were conducted according to the principles set forth in the Guide for the Care and Use of Laboratory Animals, Institute of Laboratory Animal Resources, National Research Council, DHHS Publication (NIH) 86-23 (1985). The research was supported by Naval Medical Research and Development Command Research and Technology Work Unit 61152N.MR00001.001.1383. The opinions and assertions con-rained herein are those of the authors and are not to be construed as official or reflecting the views of the Navy Department or the Naval Service at large.",
year = "1991",
month = oct,
doi = "10.1016/0091-3057(91)90573-K",
language = "English",
volume = "40",
pages = "417--422",
journal = "Pharmacology, Biochemistry and Behavior",
issn = "0091-3057",
number = "2",
}