Plasma corticosterone increases produced by extinction of operant behavior in rats

Coover, Gary D.; Goldman, Larry; Levine, Seymour

doi:10.1016/0031-9384(71)90037-0

Cited by 106 publications

(39 citation statements)

References 5 publications

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“…The same effect is observed after the omission of reinforcement during extinction (Coover, Goldman, & Levine, 1971;Davis, Memmott, McFadden, & Levine, 1976;Levine, Goldman, & Cooper, 1972). Thus, given the fact that the enhanced performance in stimulated rats appeared only during the transitions between behavioral states, it is possible that these effects were due only to a reduced stress reac-tion, with a consequently better adaptation to a new experimental situation by the stimulated rats.…”

Section: Discussionmentioning

confidence: 66%

Long-term modulation of learning following locus coeruleus stimulation: Behavioral and neurochemical data

Velly

Kempf²,

Cardo³

et al. 1985

Psychobiology

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This paper summarizes some behavioral and neurochemical data relating to the delayed effect oflocus coeruleus stimulation on the learning capabilities ofthe rat. The first observation showed that electrical stimulation of the locus coeruleus of a 15-day-old rat improved the acquisition and extinction of a food-reinforced operant task performed 4 weeks later. The neurochemical lesion of the dorsal noradrenergic bundle, 10 days before the stimulation, did not decrease the behavioral effect, whereas the neurochemical lesion of the locus coeruleus proper suppressed the improvement. Furthermore, we studied the long-term effect of the stimulation on some biochemical parameters of the coerulean system: First, the turnover of noradrenaline increased in the locus coeruleus 4 days after the stimulation, whereas it decreased 4 weeks after the treatment in the nucleus proper and in the hippocampus. Second, 4 weeks after the stimulation, the characteristics of some adrenoceptor populations were significantly changed, in particular regions of the brain. The number of al"adrenoceptors was increased in the cortex, the hippocampus, and particularly the hypothalamus. The number of al-adrenoceptors was increased in the cortex. Neither the number nor the affinity of {3 receptors was altered by the stimulation. Likewise, the number of al-, a,-, and {3-adrenoceptors in the brainstem was not changed. These results are discussed. To explain our behavioral data, we assume that the performance improvement in prestimulated rats is due, for the most part, to a reduced reaction to stressful situations. On this basis, the stressreduction hypothesis is tentatively related to the binding data showing that the most significant increase of the a2-receptors was observed in the hypothalamus.In previous studies, we showed that electrical stimulation of the lateral hypothalamus of 15-day-old rats significantly enhanced the learning of various tasks examined 4 weeks later. We first demonstrated that this stimulation improved the acquisition and extinction of a foodreinforced task (Velley & Cardo, 1977). In subsequent experiments, we observed the same effect on the acquisition and reversal of a light-dark discrimination, whether appetitively or aversively reinforced, as well as on the acquisition of a one-way avoidance task (Velley, Chassaing, & Cardo, 1981).

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Section: Discussionmentioning

confidence: 66%

Long-term modulation of learning following locus coeruleus stimulation: Behavioral and neurochemical data

Velly

Kempf²,

Cardo³

et al. 1985

Psychobiology

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“…All analyses of adrenocortical response to stress in hippocampal animals indicated normal levels (Coover et al, 1971;Jackson & Regestein, 1974;Knigge, 1961;Lanier, Van Hartesveldt, Weiss, & Isaacson, 1975;Nakadate & de Groot, 1963;Wilson & Critchlow, 1973). Most analyses of basal levels also were within normal limits (Coover et al, 1971;Jackson & Regestein, 1974;Kearley, Van Hartesveldt, & Woodruff, 1974;Lanier et al, 1975;Lengvari & Halasz, 1973;Wilson & Critchlow, 1973). Those studies reported elevated basal levels of either ACTH or corticosterone generally involved assays conducted relatively soon after surgery (Moberg, Scapagnini, de Groot, & Ganong, 1971;Nakadate & de Groot, 1963).…”

Section: Discussionmentioning

confidence: 92%

“…Mason's (1957) report of decreased levels of ACTH following stimulation of the hippocampus led to speculation that hippocampal damage might produce chronic elevation of ACTH levels. Analysis of plasma levels of ACTH or associated steroids in hippocampally damaged animals has produced reports of both elevated (Fendler, Karmos, & Telegdy, 1961;Knigge, 1961) and normal (Coover, Goldman, & Levine, 1971) levels.…”

mentioning

confidence: 99%

Neural and endocrine effects on classical conditioning: A comparison of ACTH and hippocampectomy

et al. 1985

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The effects of bilateral hippocampal lesions and systemic elevation of ACTH were compared using the classically conditioned rabbit nictitating membrane response. Animals with hippocampal lesions and unoperated animals that received ACTH (5I.U. /kg) exhibited a facilitated rate of acquisition and decreased conditioned response onset latency relative to normal control groups or animals with cortical lesions. The administration of ACTH did not alter performance in animals with hippocampal damage, indicating that the effects of these treatments are not additive. The performance of a second group of animals that was treated with a smaller dosage of ACTH (2.5 I.U./kg) was no different from that of any other group, suggesting a dose-dependent effect of the hormone. The selective replication of hippocampal deficits ascribed to a loss of response modulation suggests that ACTH may influence learning by stimulating hippocampal neurons.

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“…However, all of these experiments used shock, which releases steroids and unequivocal support for the uncertainty argu ment can only come from studies using appetitive reinforcement. In a study of Coover et al (1971), uncertainty was introduced by changing the rat's schedule of reinforcement after training; rats were trained to lever press on a continuous reinforcement schedule, and then reinforcement was withheld. Measures of the stress steroids demonstrated a rise in plasma corticosterone during extinction.…”

Section: Corticosteroids and Animal Behaviourmentioning

confidence: 99%

Modern Biochemical Concepts of Anxiety

Dm¹

1974

Int Pharmacopsychiatry

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Evidence from clinical studies suggest that corticosteroids produce agitation and enhance anxiety. It is proposed that anxiety results from the neurochemical changes induced by corticosteroids. Evidence was presented to show that the critical changes for anxiety are due to modifications in serotonin pathways in the tegmental region of the midbrain. In support of this, known antianxiety agents block these changes and so it is argued that the future search for anxiolytic drugs should focus on these neurochemical pathways.

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Plasma corticosterone increases produced by extinction of operant behavior in rats

Cited by 106 publications

References 5 publications

Long-term modulation of learning following locus coeruleus stimulation: Behavioral and neurochemical data

Long-term modulation of learning following locus coeruleus stimulation: Behavioral and neurochemical data

Neural and endocrine effects on classical conditioning: A comparison of ACTH and hippocampectomy

Modern Biochemical Concepts of Anxiety

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