scholarly journals Intragastric nutrient infusion reduces motivation for food in male and female rats

2018 ◽  
Vol 315 (1) ◽  
pp. E81-E90 ◽  
Author(s):  
Calyn B. Maske ◽  
Gregory C. Loney ◽  
Nicole Lilly ◽  
Sarah J. Terrill ◽  
Diana L. Williams
Keyword(s):  
Receptor Antagonist ◽  
Food Reward ◽  
Fixed Ratio ◽  
Progressive Ratio ◽  
Test Session ◽  
Suppressive Effect ◽  
Female Rats ◽  
Operant Responding ◽  
Male And Female Rats ◽  
Nutrient Infusion

The idea that gut-derived satiation signals influence food reward has recently gained traction, but this hypothesis is largely based on studies focused on neural circuitry, not the peripherally released signals. Here, we directly tested the hypothesis that intragastric (IG) nutrient infusion can suppress motivation for food. In a series of experiments, IG sucrose infusion (15 kcal) significantly and reliably reduced operant responding for a sucrose reward on a progressive ratio (PR) schedule. Moreover, food deprivation for 24 h before the test session did not prevent the suppressive effect of nutrients. The suppressive effect of IG sucrose on fixed ratio 5 (FR5) operant responding was also assessed as a comparison. The effect of IG nutrients to reduce motivation was not limited to sucrose; IG Ensure infusion (9.3 kcal) also significantly reduced PR operant responding for sucrose pellets. To verify that these effects were not secondary to the osmotic challenge of concentrated nutrients, we tested IG infusion of noncaloric saline solutions equiosmolar to 40% sucrose or Ensure and found no effect. Finally, we focused on glucagon-like peptide-1 (GLP-1) and cholecystokinin (CCK) as candidate mediators for the effect of IG nutrients. Pretreatment with exendin-9, a GLP-1 receptor antagonist, delivered intraperitoneally, significantly attenuated the ability of IG nutrients to suppress PR responding and breakpoint in males, but not in females, whereas pretreatment with devazepide, a CCKA receptor antagonist, failed to do so in both sexes. Together, these data support the idea that nutrient-induced satiation signals influence food reward and may implicate GLP-1 in this process.

Further quantification of pigs needs for food using operant conditioning

1989 ◽  
Vol 1989 ◽  
pp. 91-91
Author(s):  
A.B. Lawrence ◽  
A.W. Illius
Keyword(s):  
Operant Conditioning ◽  
Food Restriction ◽  
Food Reward ◽  
Fixed Ratio ◽  
Progressive Ratio ◽  
Operant Responding ◽  
Motivational States ◽  
Feeding Motivation ◽  
Ad Libitum Intake ◽  
High Level

The study of motivational states underlying behaviour is seen as critical to understanding the implications of restricted husbandry conditions on animal welfare. Yet the measurement of the strength of motivation remains a perennial problem in welfare studies. Previous work at Edinburgh using operant conditioning identified an apparently high level of feeding motivation throughout the day in pigs fed [ARC, 1981] recommended levels for sows and boars [Lawrence et al. 1988]. Pigs trained to press a panel consistently 10 times for a food reward (fixed ratio or FR responding) maintained high levels of panel pressing across the day when offered 0.6 of their ad libitum intake approximating to ARC (1981) recommended feeding levels. However, as the level of operant responding required was not great, it is arguable to what extend these results demonstrate a strong need for food by pigs on restricted feeding. The present paper reports on an experiment to test more accutely the strength of feeding motivation in relation to food restriction by comparing responding on FR with that on a progressive ratio (PR) where the animal has to work progressively harder for successive rewards. It was hoped that PR. reputedly a sensitive measure of motivation, would indicate with greater certainty restrict fed pigs need for food.

5-HT1B receptor agonist attenuates cocaine self-administration after protracted abstinence and relapse in rats

2021 ◽  
pp. 026988112110192
Author(s):  
Samantha N Scott ◽  
Raul Garcia ◽  
Gregory L Powell ◽  
Sophia M Doyle ◽  
Brielle Ruscitti ◽  
...  
Keyword(s):  
Cue Reactivity ◽  
Fixed Ratio ◽  
Test Session ◽  
Female Rats ◽  
Male Rats ◽  
Inhibitory Effects ◽  
Self Administration ◽  
Training Dose ◽  
Male And Female Rats ◽  
Cocaine Seeking

Background: The 5-HT1B receptor (5-HT1BR) agonist, CP94253, enhances cocaine intake during maintenance of self-administration (SA) but attenuates intake after 21 days of forced abstinence in male rats. Aims: We examined whether CP94253 attenuates cocaine intake in female rats after a period of abstinence, and if these attenuating effects persist or revert to enhancing cocaine intake during resumption (i.e. relapse) of daily cocaine SA. Methods: Male and female rats trained to lever press on a fixed ratio 5 schedule of cocaine reinforcement underwent ⩾21 days of forced abstinence. They were then tested for the effects of CP94253 (5.6 mg/kg, SC) or vehicle on cocaine SA. During the test session, rats had 1-h access to the training dose of cocaine (0.75 mg/kg, IV) followed by 1-h access to a lower cocaine dose (0.075 mg/kg, IV). Rats then resumed cocaine SA for 15 days to mimic relapse and were retested as done previously. Subsequently, rats underwent abstinence again (21–60 days) and were tested for CP94253 effects on locomotion and cue reactivity (i.e. responding for light/tone cues previously paired with cocaine infusions). Results: Regardless of sex, CP94253 decreased cocaine intake after abstinence and during resumption of SA and decreased cue reactivity while having no effect on locomotion. Conclusions: CP94253 decreases cocaine intake and cocaine seeking in both males and females even after resumption of cocaine SA. These findings suggest that the inhibitory effects of CP94253 observed after abstinence are long-lasting, and therefore, 5-HT1BR agonists may have clinical efficacy as anti-relapse medications for cocaine use disorders.

scholarly journals Sex Differences in Escalated Methamphetamine Self-Administration and Altered Gene Expression Associated With Incubation of Methamphetamine Seeking

2019 ◽  
Vol 22 (11) ◽  
pp. 710-723 ◽  
Author(s):  
Atul P Daiwile ◽  
Subramaniam Jayanthi ◽  
Bruce Ladenheim ◽  
Michael T McCoy ◽  
Christie Brannock ◽  
...  
Keyword(s):  
Sex Differences ◽  
Nucleus Accumbens ◽  
Fixed Ratio ◽  
Female Rats ◽  
Male Rats ◽  
Mrna Levels ◽  
Self Administration ◽  
Male And Female ◽  
Orexin Receptors ◽  
Male And Female Rats

Abstract Background Methamphetamine (METH) use disorder is prevalent worldwide. There are reports of sex differences in quantities of drug used and relapses to drug use among individuals with METH use disorder. However, the molecular neurobiology of these potential sex differences remains unknown. Methods We trained rats to self-administer METH (0. 1 mg/kg/infusion, i.v.) on an fixed-ratio-1 schedule for 20 days using two 3-hour daily METH sessions separated by 30-minute breaks. At the end of self-administration training, rats underwent tests of cue-induced METH seeking on withdrawal days 3 and 30. Twenty-four hours later, nucleus accumbens was dissected and then used to measure neuropeptide mRNA levels. Results Behavioral results show that male rats increased the number of METH infusions earlier during self-administration training and took more METH than females. Both male and female rats could be further divided into 2 phenotypes labeled high and low takers based on the degree of escalation that they exhibited during the course of the METH self-administration experiment. Both males and females exhibited incubation of METH seeking after 30 days of forced withdrawal. Females had higher basal mRNA levels of dynorphin and hypocretin/orexin receptors than males, whereas males expressed higher vasopressin mRNA levels than females under saline and METH conditions. Unexpectedly, only males showed increased expression of nucleus accumbens dynorphin after METH self-administration. Moreover, there were significant correlations between nucleus accumbens Hcrtr1, Hcrtr2, Crhr2, and Avpr1b mRNA levels and cue-induced METH seeking only in female rats. Conclusion Our results identify some behavioral and molecular differences between male and female rats that had self-administered METH. Sexual dimorphism in responses to METH exposure should be considered when developing potential therapeutic agents against METH use disorder.

scholarly journals The Alpha-1 Adrenergic Receptor Antagonist Prazosin Reduces Binge-Like Eating in Rats

Nutrients ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1569
Author(s):  
Callum Hicks ◽  
Valentina Sabino ◽  
Pietro Cottone
Keyword(s):  
Receptor Antagonist ◽  
Adrenergic Receptor ◽  
Fixed Ratio ◽  
Progressive Ratio ◽  
Noradrenergic System ◽  
Palatable Food ◽  
Schedule Of Reinforcement ◽  
Male Wistar Rats

Background: Binge-eating disorder is a pervasive addiction-like disorder that is defined by excessive and uncontrollable consumption of food within brief periods of time. The aim of the current study was to examine the role of the brain noradrenergic system in binge-like eating through the use of the alpha-1 adrenergic receptor antagonist prazosin. Methods: For this purpose, we employed a limited access model whereby male Wistar rats were allowed to nosepoke for either chow (Chow rats) or a sugary, highly palatable food (Palatable rats) for 1 h/day. The effects of prazosin (0, 0.5, 1 and 2 mg/kg, i.p.) were tested in a fixed ratio 1 (FR1) and progressive ratio (PR) schedule of reinforcement. Results: The results show that prazosin preferentially reduced the responses for palatable food in a FR1 reinforcement schedule; when tested in a PR schedule of reinforcement, prazosin increased breakpoint in both Chow and Palatable rats, but more potently and more efficaciously in the latter. Our results suggest that prazosin treatment preferentially increased the motivational properties of the palatable diet. Conclusions: The current findings provide the characterization of the effects of prazosin on binge-like eating and offer support to the existing literature showing the important role of the noradrenergic system in addiction-like behavior.

The effects of pyridostigmine bromide on progressive ratio performance in male and female rats

2001 ◽  
Vol 68 (1) ◽  
pp. 81-85 ◽  
Author(s):  
Frans van Haaren ◽  
Stephen C. Haworth ◽  
Shonnie M. Bennett ◽  
Bethany A. Cody
Keyword(s):  
Progressive Ratio ◽  
Pyridostigmine Bromide ◽  
Female Rats ◽  
Male And Female ◽  
Male And Female Rats

Effects of the glucocorticoid receptor antagonist PT150 on stress-induced fentanyl seeking in male and female rats

2021 ◽  
Author(s):  
Lindsey R. Hammerslag ◽  
Emily D. Denehy ◽  
Benjamin Carper ◽  
Tracy L. Nolen ◽  
Mark A. Prendergast ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Receptor Antagonist ◽  
Female Rats ◽  
Male And Female ◽  
Male And Female Rats

scholarly journals Comparison of chemotherapy effects on mechanical sensitivity and food-maintained operant responding in male and female rats

2019 ◽  
Vol 31 (5) ◽  
pp. 477-490 ◽  
Author(s):  
Luke P. Legakis ◽  
Clare M. Diester ◽  
Edward A. Townsend ◽  
Ladan Karim-Nejad ◽  
Sidney Stevens Negus
Keyword(s):  
Female Rats ◽  
Mechanical Sensitivity ◽  
Male And Female ◽  
Operant Responding ◽  
Male And Female Rats

scholarly journals Sucrose self-administration and CNS activation in the rat

2011 ◽  
Vol 300 (4) ◽  
pp. R876-R884 ◽  
Author(s):  
Dianne P. Figlewicz ◽  
Jennifer L. Bennett-Jay ◽  
Sepideh Kittleson ◽  
Alfred J. Sipols ◽  
Aryana Zavosh
Keyword(s):  
Energy Homeostasis ◽  
Food Reward ◽  
Fixed Ratio ◽  
Progressive Ratio ◽  
Stria Terminalis ◽  
Self Administration ◽  
Bed Nucleus ◽  
Medial Hypothalamus ◽  
Fos Expression

We have previously reported that administration of insulin into the arcuate nucleus of the hypothalamus decreases motivation for sucrose, assessed by a self-administration task, in rats. Because the pattern of central nervous system (CNS) activation in association with sucrose self-administration has not been evaluated, in the present study, we measured expression of c-Fos as an index of neuronal activation. We trained rats to bar-press for sucrose, according to a fixed-ratio (FR) or progressive-ratio (PR) schedule and mapped expression of c-Fos immunoreactivity in the CNS, compared with c-Fos expression in handled controls. We observed a unique expression of c-Fos in the medial hypothalamus (the arcuate, paraventricular, retrochiasmatic, dorsomedial, and ventromedial nuclei) in association with the onset of PR performance, and expression of c-Fos in the lateral hypothalamus and the bed nucleus of stria terminalis in association with the onset of FR performance. c-Fos expression was increased in the nucleus accumbens of both FR and PR rats. Our study emphasizes the importance of both hypothalamic energy homeostasis circuitry and limbic circuitry in the performance of a food reward task. Given the role of the medial hypothalamus in regulation of energy balance, our study suggests that this circuitry may contribute to reward regulation within the larger context of energy homeostasis.

scholarly journals Pain‐Related Depression of Operant Responding Maintained by Social Access or Food in Male and Female Rats

2021 ◽  
Vol 35 (S1) ◽  
Author(s):  
Sidney Negus ◽  
Amber Baldwin ◽  
Samuel Marsh ◽  
Matthew Banks ◽  
Edward Townsend ◽  
...  
Keyword(s):  
Female Rats ◽  
Male And Female ◽  
Operant Responding ◽  
Male And Female Rats
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