scholarly journals Sex differences in sucrose reinforcement in Long-Evans rats

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Jeffrey W. Grimm ◽  
Katherine North ◽  
Madeleine Hopkins ◽  
Kyle Jiganti ◽  
Alex McCoy ◽  
...  

Abstract Background There are sex differences in addiction behaviors. To develop a pre-clinical animal model to investigate this, the present study examined sex differences in sucrose taking and seeking using Long-Evans rats. Methods Five experiments were conducted using separate groups of subjects. The first two examined sucrose or saccharin preference in two-bottle home cage choice tests. Experiment three assessed sucrose intake in a binge model with sucrose available in home cage bottles. Experiments four and five utilized operant-based procedures. In experiment four rats responded for sucrose on fixed and progressive ratio (FR, PR) schedules of reinforcement over a range of concentrations of sucrose. A final component of experiment four was measuring seeking in the absence of sucrose challenged with the dopamine D1 receptor antagonist SCH23390. Experiment five assessed responding for water on FR and PR schedules of reinforcement. Results When accounting for body weight, female rats consumed more sucrose than water; but there was no sex difference in saccharin preference over a range of saccharin concentrations. When accounting for body weight, females consumed more sucrose than males in the binge model, and only females increased binge intake over 14 days of the study. Females responded at higher rates for sucrose under both FR and PR schedules of reinforcement. Females responded at higher rates in extinction (seeking); SCH23390 reduced sucrose seeking of both females and males. Females responded at higher rates for water on FR and PR schedules than males, although rates of responding were low and decreased over sessions. Conclusions Across bottle-choice, binge intake, and operant procedures, female Long-Evans rats consumed more sucrose and responded at higher rates for sucrose. Although females also responded more for water, the vigor of responding did not explain the consistent sex difference in sucrose taking and seeking. The sex difference in sucrose taking was also not explained by sweet preference, as there was no sex difference in saccharin preference. These data provide a pre-clinical model to further evaluate sex differences in addiction behaviors and manipulations designed to reduce them.

2021 ◽  
Author(s):  
Jeffrey Grimm ◽  
Katherine North ◽  
Madeleine Hopkins ◽  
Kyle Jiganti ◽  
Alex McCoy ◽  
...  

Abstract Background: There are sex differences in addiction behaviors. To develop a pre-clinical animal model to investigate this, the present study examined sex differences in sucrose taking and seeking using LongEvans rats. Methods: Five experiments were conducted using separate groups of subjects. The first two examined sucrose or saccharin preference in two-bottle home cage choice tests. Experiment three assessed sucrose intake in a binge model with sucrose available in home cage bottles. Experiments four and five utilized operant-based procedures. In Experiment four rats responded for sucrose on fixed and progressive ratio (FR, PR) schedules of reinforcement over a range of concentrations of sucrose. A final component of experiment four was measuring seeking in the absence of sucrose challenged with the dopamine D1 receptor antagonist SCH23390. Experiment five assessed responding for water on FR and PR schedules of reinforcement. Results: When accounting for body weight, female rats consumed more sucrose than water; but there was no sex difference in saccharin preference over a range of saccharin concentrations. When accounting for body weight, females consumed more sucrose than males in the binge model, and only females increased binge intake over the 14 days of the study. Females responded at higher rates for sucrose under both FR and PR schedules of reinforcement. Females responded at higher rates in extinction (seeking); SCH23390 reduced sucrose seeking of both females and males. Females responded at higher rates for water on FR and PR schedules than males, although rates of responding were low and decreased over sessions. Conclusions: Across bottle-choice, binge intake, and operant procedures, female Long-Evans rats consumed more sucrose and responded at higher rates for sucrose. Although females also responded more for water, the vigor of responding did not explain the consistent sex difference in sucrose taking and seeking. The sex difference in sucrose taking was also not explained by sweet preference, as there was no sex difference in saccharin preference. These data corroborate with findings of sex differences in addiction behaviors in humans, providing a pre-clinical model to further evaluate sex differences in these behaviors and manipulations designed to reduce them.


1966 ◽  
Vol 44 (1) ◽  
pp. 95-101 ◽  
Author(s):  
J. R. Beaton ◽  
A. J. Szlavko ◽  
J. A. F. Stevenson

The effect of various factors on excretion of a lipid-mobilizing activity in FMS IA (anorexigenic) and in FMS IB (fat-mobilizing) by the fasting rat has been investigated. During fasting, the greatest excretion of such activity in FMS IA and FMS IB occurred in the first 24 hours and diminished thereafter up to 72 hours; and the specific activity of FMS IB was greatest in the first 24 hours whereas that of FMS IA was constant throughout. The hypothalamicobese rat excretes FMS IA and FMS IB in greater than normal amounts. The alloxan-diabetic rat excretes less total activity of FMS IA and IB than do control animals. Young male rats excrete greater amounts of FMS IB, but not of FMS IA, than do adult rats, the greatest excretion per 100 g body weight being observed at approximately 37 days of age. At 27 days of age (prepuberty), male rats excreted a greater total activity of FMS IB but not of FMS IA than did female rats. At 90 days of age (post-puberty), there was no apparent sex difference in the amount of total activity of FMS IB excreted per rat, but when expressed per 100 g body weight, females excreted more FMS IB than did males.


1968 ◽  
Vol 22 (2) ◽  
pp. 547-554 ◽  
Author(s):  
Jan W. Kakolewski ◽  
Verne C. Cox ◽  
Elliot S. Valenstein

Data are presented to demonstrate that the effects of gonadectomy on body weight and food consumption differ in male and female rats. The findings are related to the authors' report of sex differences in the effects of ventromedial hypothalamic damage. A review of the literature on the relationship of the gonads to body weight in different species is presented.


2004 ◽  
Vol 5 (4) ◽  
pp. 255-264 ◽  
Author(s):  
Terry A. Lennie

Food intake and body weight changes in response to induction of acute inflammation were examined in intact cycling females, ovariectomized females, and sham-operated male rats. In intact females, body weight and feeding responses were compared between rats in which inflammation was induced on day of estrus with rats in which inflammation was induced on day of diestrus. Anorexia and weight loss were more severe in the female rats with inflammation induced on estrus day, which coincides with peak serum estrogen levels. In ovariectomized females, inflammation was induced the day after rats received injections of estrogen, progesterone, or sesame oil (vehicle). Males received vehicle injections. Among female rats, the group that received estradiol injections the previous day displayed the most severe anorexia. The least severe anorexia was observed in female rats that received progesterone the previous day. Food intake of female rats that received vehicle injections prior to induction of inflammation was greater than the rats receiving estrogen but less than the rats receiving progesterone. Male rats displayed the most severe anorexia and greatest weight loss. These data suggest that, although females exposed to estradiol prior to induction of acute inflammation display more severe anorexia than those exposed to progesterone, it may be that progesterone attenuates severity of anorexia rather than estrogen solely potentiating severity. Male rats, however, appear to experience the most severe anorexia in response to this form of inflammation.


PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260577
Author(s):  
Alyssa Bernanke ◽  
Elizabeth Burnette ◽  
Justine Murphy ◽  
Nathaniel Hernandez ◽  
Sara Zimmerman ◽  
...  

Females are more affected by psychiatric illnesses including eating disorders, depression, and post-traumatic stress disorder than males. However, the neural mechanisms mediating these sex differences are poorly understood. Animal models can be useful in exploring such neural mechanisms. Conditioned taste aversion (CTA) is a behavioral task that assesses how animals process the competition between associated reinforcing and aversive stimuli in subsequent task performance, a process critical to healthy behavior in many domains. The purpose of the present study was to identify sex differences in this behavior and associated neural responses. We hypothesized that females would value the rewarding stimulus (Boost®) relative to the aversive stimulus (LiCl) more than males in performing CTA. We evaluated behavior (Boost® intake, LiCl-induced behaviors, ultrasonic vocalizations (USVs), CTA performance) and Fos activation in relevant brain regions after the acute stimuli [acute Boost® (AB), acute LiCl (AL)] and the context-only task control (COT), Boost® only task (BOT) and Boost®-LiCl task (BLT). Acutely, females drank more Boost® than males but showed similar aversive behaviors after LiCl. Females and males performed CTA similarly. Both sexes produced 55 kHz USVs anticipating BOT and inhibited these calls in the BLT. However, more females emitted both 22 kHz and 55 kHz USVs in the BLT than males: the latter correlated with less CTA. Estrous cycle stage also influenced 55 kHz USVs. Fos responses were similar in males and females after AB or AL. Females engaged the gustatory cortex and ventral tegmental area (VTA) more than males during the BOT and males engaged the amygdala more than females in both the BOT and BLT. Network analysis of correlated Fos responses across brain regions identified two unique networks characterizing the BOT and BLT, in both of which the VTA played a central role. In situ hybridization with RNAscope identified a population of D1-receptor expressing cells in the CeA that responded to Boost® and D2 receptor-expressing cells that responded to LiCl. The present study suggests that males and females differentially process the affective valence of a stimulus to produce the same goal-directed behavior.


2021 ◽  
pp. 913-920
Author(s):  
Ľ Janovičová ◽  
B. Gromová ◽  
D. Drobná ◽  
B. Konečná ◽  
E. Renczés ◽  
...  

Extracellular DNA (ecDNA) activates immune cells and is involved in the pathogenesis of diseases associated with inflammation such as sepsis, rheumatoid arthritis or metabolic syndrome. DNA can be cleaved by deoxyribonucleases (DNases), some of which are secreted out of cells. The aim of this experiment was to describe plasma DNase activity in relation to extracellular DNA in adult rats, to analyse potential sex differences and to prove whether they are related to endogenous testosterone. Adult Lewis rats (n=28) of both sexes were included in the experiment. Male rats were gonadectomized or sham-operated and compared to intact female rats. Plasma ecDNA and DNase activity were measured using fluorometry and single radial enzyme diffusion assay, respectively. Concentrations of nuclear ecDNA and mitochondrial ecDNA were determined using real-time PCR. Females had 60% higher plasma DNase activity than males (p=0.03). Gonadectomy did not affect plasma DNase in males. Neither the concentration of total ecDNA, nor nuclear or mitochondrial DNA in plasma differed between the groups. No significant correlations between DNase and ecDNA were found. From previous studies on mice, it was expected, that male rats will have higher DNase activity. In contrast, our study in rats showed the opposite sex difference. This sex difference seems not to be caused by endogenous testosterone. Interestingly, no sex differences were observed in plasma ecDNA suggesting a complex or missing association between plasma ecDNA and DNase. The observed sex difference in plasma DNase should be taken into account in animal models of ecDNA-associated diseases.


Metabolites ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 293
Author(s):  
Jose Manuel Fernandez-Garcia ◽  
Beatriz Carrillo ◽  
Patricia Tezanos ◽  
Paloma Collado ◽  
Helena Pinos

Phytoestrogens are considered beneficial for health, but some studies have shown that they may cause adverse effects. This study investigated the effects of genistein administration during the second week of life on energy metabolism and on the circuits regulating food intake. Two different genistein doses, 10 or 50 µg/g, were administered to male and female rats from postnatal day (P) 6 to P13. Physiological parameters, such as body weight and caloric intake, were then analyzed at P90. Moreover, proopiomelanocortin (POMC) expression in the arcuate nucleus (Arc) and orexin expression in the dorsomedial hypothalamus (DMH), perifornical area (PF) and lateral hypothalamus (LH) were studied. Our results showed a delay in the emergence of sex differences in the body weight in the groups with higher genistein doses. Furthermore, a significant decrease in the number of POMC-immunoreactive (POMC-ir) cells in the Arc in the two groups of females treated with genistein was observed. In contrast, no alteration in orexin expression was detected in any of the structures analyzed in either males or females. In conclusion, genistein can modulate estradiol’s programming actions on the hypothalamic feeding circuits differentially in male and female rats during development.


1979 ◽  
Vol 80 (1) ◽  
pp. 21-26 ◽  
Author(s):  
D. B. ENDRES ◽  
R. J. MILHOLLAND ◽  
F. ROSEN

The effects in rats of adrenalectomy, hypophysectomy, ovariectomy or combinations of these operations on the concentrations of glucocorticoid receptors in the cytosol of liver and thymus were measured. The concentrations of glucocorticoid receptors were lower in cytosols from liver and thymus of female than of male rats. After adrenalectomy, there was a significant increase in the concentrations of receptors measured in the cytoplasm from the liver and thymus of female rats and from the liver of male rats. After adrenalectomy or hypophysectomy, there was no sex difference in the concentrations of glucocorticoid receptors in cytosols of liver or thymus. After ovariectomy, the concentration of receptors in cytosols from the thymus, but not from the liver, increased. Ovariectomized rats responded to adrenalectomy in the same way as intact male rats. The different responses shown by male and female rats to endocrine manipulation probably depend upon associated changes in plasma corticosterone concentrations which are influenced by the ovary. Differences in response between the liver and thymus probably reflect a preferential distribution of corticosterone to the liver rather than to the thymus.


2020 ◽  
Author(s):  
Ying Shi ◽  
Fangzhi Yue ◽  
Lin Xing ◽  
Shanyu Wu ◽  
Lin Wei ◽  
...  

Abstract Background: Sex differences in obesity and related metabolic diseases are well recognized, however, the mechanism has not been elucidated. Gut microbiota and its metabolites may play a vital role in the development of obesity and metabolic diseases. The aim of the present study was to investigate sex differences in gut microbiota and its metabolites in a high-fat-diet (HFD) obesity rats and identify microbiota genera potentially contributing to such differences in obesity and non-alcoholic fatty liver disease (NAFLD) susceptibility.Methods: Sprague–Dawley rats were divided into four groups (eight animals per group): (1) male rats on a normal diet (MND), (2) male rats on HFD (MHFD), (3) female rats on a normal diet (FND), and (4) female rats on HFD (FHFD). Body weight, liver pathology, gut microbiota and short/medium chain fatty acids in colon contents were compared between different sexes.Results: HFD induced more body weight gain and fat storage in female rats, however, lower hepatic steatosis in FHFD than in MHFD rats was observed. When considering gut microbiota composition, FHFD rats had lower microbiome diversity than MHFD. A significant increase of Firmicutes phylum, along with Bilophila and Blautia genus was detected in MHFD rats, as compared with FHFD, which showed increased relative abundance of Murimonas. Moreover, propionic and lauric acid levels were higher in FHFD than those in MHFD rats. Conclusions: HFD induced sex-related alterations in gut microbiome and fatty acids. Furthermore, the genus Bilophila, Blautia and Murimonas might contribute to sex differences observed in obesity and NAFLD susceptibility.


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