LONG-TERM CHOLINERGIC STIMULATION OF PONTINE NUCLEI: EFFECTS ON PARADOXICAL SLEEP AND MEMORY.
Item
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Title
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LONG-TERM CHOLINERGIC STIMULATION OF PONTINE NUCLEI: EFFECTS ON PARADOXICAL SLEEP AND MEMORY.
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Identifier
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AAI8319799
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identifier
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8319799
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Creator
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SHIROMANI, PRIYATTAM J.
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Contributor
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William Fishbein | S t e v e n E l l m a n
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Date
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1983
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Language
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English
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Publisher
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City University of New York.
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Subject
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Psychology, Psychobiology
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Abstract
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A number of studies have shown that acute administration of cholinergic agonists into the brainstem produces some or all of the tonic and phasic aspects of paradoxical sleep (PS). While these studies support the hypothesis that alterations in activity of a discrete set of reticular neurons might trigger PS, no study has charted long-term alterations in PS induced by chronic infusions of cholinergic agonist-antagonists into the pons. In this study, an Alzet osmotic mini-pump is used to infuse either carbachol (0.5 (mu)g/hr), scopolamine (9.0 (mu)g/hr) or saline into the brainstem or fourth ventricle.;In Experiment 1, 51 male rats are implanted with chronic indwelling EEG and EMG electrodes and an L-shaped cannula aimed at various brainstem sites or the fourth ventricle. Following recovery from surgery, a 24 hr baseline sleep record is obtained. The next morning the Alzet mini-pump is implanted and nine consecutive 24 hr sleep records obtained (7 days drug + 2 days post-drug). Two weeks later a 24 hr post-experimental record is obtained. Within groups repeated measures ANOVAs show that midline infusions of carbachol into the area around the genu of the VII nerve produce an 88% increase in PS. Midline infusions into other brainstem areas or the fourth ventricle do not alter PS. The PS increase occurs only during the night cycle and is due to an increase in PS frequency. Scopolamine, on the other hand, decreases PS by an average of 60% and the effect is not site-specific. The PS decrease occurs during the day cycle and it is due to a decrease in PS frequency and duration.;In Experiment 2, the period of carbachol infusion is increased to two weeks. Midline infusions into areas caudal to the genu of the VII nerve produce contradictory results in that PS is increased during the day cycle and decreased during the night cycle. It is suggested that the day cycle PS increase might be a PS rebound.;Experiment 3 tests the effects of such chronic infusions on retention of a learned response. Independent groups of rats are implanted with pumps containing either carbachol, scopolamine or saline. Subsequently the rats are given 50 consecutive trials in a shuttlebox and tested for retention 7 or 21 days later. At 7 days the scopolamine animals show significantly poor retention compared to carbachol or saline animals. At 21 days, however, all animals show good retention. It is suggested that scopolamine may have produced a retrieval failure at 7 days.;The results of this dissertation provide further evidence of the important role of the cholinergic system in PS and memory.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Psychology
