Rats were trained over 40 days to lever-press for food reward under a schedule of differential reinforcement of low rates of response with a 20-s criterion (DRL 20), following seven sessions of continuous reinforcement. The effect of injecting a beta-adrenergic blocker, propranolol (5 mg/kg IP), before and at two different delays after each daily session of DRL were investigated. In Experiment I, rats drugged 5-8 min before every session earned fewer reinforcements compared to controls, and showed impaired temporal discrimination. In Experiment II, this result was not replicated, but similar effects were clear in animals drugged pre-session from the 15th day of acquisition. By contrast, an improved temporal discrimination, and increased number of reinforcements were seen in rats drugged 5-8 min after every session. In Experiment III, the post-session effects were replicated and found also in rats drugged 4-5.5 h after each session. These results suggest that propranolol has an acute effect on DRL responding which resembles that of anxiolytics, and a chronic effect which opposes the acute one.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1007/BF00427913 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
A preliminary study on the effects of Xiang Shao granules on reproductive endocrinology in drugged ovariectomised rats.
J Ovarian Res
October 2024
Department of Obstetrics and Gynecology, The Affiliated Changzhou Second People's Hospital of Nanjing Medical University, Changzhou, Jiangsu Province, 213000, PR China.
Objective: To establish a rat model of pharmacological ovariectomy by GnRH-a injection and to preliminarily investigate the reproductive endocrine effects of Xiangshao granules on pharmacologically ovariectomized rats.
Methods: A rat model of pharmacological ovariectomy was established by injecting female rats with Gonadotropin-releasing hormone agonist(GnRH-a).The rats were randomly divided into four groups: GnRH-a injected saline group (GnRH-a + NS); GnRH-a injected oestradiol group (GnRH-a + E2); GnRH-a injected Xiangshao granule group (GnRH-a + Xiangshao), and the control group of saline-injected rats (NS + NS).
The neuropharmacological profile of interval responding during operant tasks.
Naunyn Schmiedebergs Arch Pharmacol
October 2024
Laboratoire "Stress, Immunité, Pathogènes" EA 7300, Université de Lorraine, Campus Santé, 9 avenue de la Forêt de Haye, Vandoeuvre-les-Nancy, 54500, France.
Responses occurring during intervals of operant tasks have been subdivided as interim, facultative, and terminal, depending on the time between response onset and reward. Although interval responses, also known as adjunctive responses, have been described in pigeons, rats, mice, monkeys, and humans, most experiments have been conducted in rats. We review the neurochemical basis of interval responses and examine the hypothesis that these responses modulate operant performance.
View Article and Find Full Text PDFCyclophosphamide enfeebles myocardial isometric contraction force via RIP1/RIP3/MLKL/TRPM7-mediated necroptosis.
Biomed Pharmacother
July 2023
Department of Mechanical Engineering, School of Sciences and Engineering, The American University in Cairo, New Cairo 11835, Egypt. Electronic address:
This study explores the negative impact of cyclophosphamide (CP) on cardiac contractility by specifically examining its effect on the active and passive tension of the cardiac muscle in-vitro and revealing the mechanism through which CP induces myocardial insult in-vivo. In young male Sprague-Dawley rats, cardiac toxicity was induced by a single intraperitoneal injection of CP (150 mg/kg body weight). Axial heart tissue slices were electrically stimulated, and the total isometric contraction force was measured at varying pretension levels.
View Article and Find Full Text PDFEffects of Early Risperidone Treatment on Metabolic Parameters in Socially Isolated Rats-Implication of Antipsychotic Intervention across Developmental Stages of Schizophrenia.
J Integr Neurosci
January 2023
Department of Physiology and Biophysics, National Defense Medical Center, 114 Taipei, Taiwan.
Background: Second-generation antipsychotics (SGAs) is thought responsible for the metabolic abnormalities of schizophrenic patients, however, some untreated schizophrenic patients had already developed problems with glucose metabolism. The present study examined the hypothesis that schizophrenia itself but not risperidone, an extensively employed SGA, is accountable for metabolic abnormalities.
Methods: A 56-day risperidone regimen (1 mg/kg/day) was employed for rats of social isolation rearing (SIR) beginning at different developmental stage (28 or 56 days after weaning, i.
Increased mGlu5 mRNA expression in BLA glutamate neurons facilitates resilience to the long-term effects of a single predator scent stress exposure.
Brain Struct Funct
September 2021
Psychology Department, Behavioral and Cognitive Neuroscience Program, University of Florida, 114 Psychology Building, 945 Center Drive, Gainesville, FL, 32611-2250, USA.
Post-traumatic stress disorder (PTSD) develops in a subset of individuals exposed to a trauma with core features being increased anxiety and impaired fear extinction. To model the heterogeneity of PTSD behavioral responses, we exposed male Sprague-Dawley rats to predator scent stress once for 10 min and then assessed anxiety-like behavior 7 days later using the elevated plus maze and acoustic startle response. Rats displaying anxiety-like behavior in both tasks were classified as stress Susceptible, and rats exhibiting behavior no different from un-exposed Controls were classified as stress Resilient.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!