1
|
McNealy KR, Oevermann MW, Knabel ML, Fitzwater A, Gipson CD, Barrett ST, Bevins RA. Repeated exposure to physiologically effective doses of contraceptive hormones ethinyl estradiol or levonorgestrel do not alter the reinforcing effects of a brief visual stimulus in ovary-intact rats. Horm Behav 2024; 161:105506. [PMID: 38387104 DOI: 10.1016/j.yhbeh.2024.105506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 02/09/2024] [Accepted: 02/14/2024] [Indexed: 02/24/2024]
Abstract
Estradiol and progesterone potentiate and attenuate reward processes, respectively. Despite these well-characterized effects, there is minimal research on the effects of synthetic estrogens (e.g., ethinyl estradiol, or EE) and progestins (e.g., levonorgestrel, or LEVO) contained in clinically-utilized hormonal contraceptives. The present study characterized the separate effects of repeated exposure to EE or LEVO on responding maintained by a reinforcing visual stimulus. Forty ovary-intact female Sprague-Dawley rats received either sesame oil vehicle (n = 16), 0.18 μg/day EE (n = 16), or 0.6 μg/day LEVO (n = 8) subcutaneous injections 30-min before daily one-hour sessions. Rats' responding was maintained by a 30-sec visual stimulus on a Variable Ratio-3 schedule of reinforcement. The day after rats' last session, we determined rats estrous cycle phase via vaginal cytology before sacrifice and subsequently weighing each rat's uterus to further verify the contraceptive hormone manipulation. The visual stimulus functioned as a reinforcer, but neither EE nor LEVO enhanced visual stimulus maintained responding. Estrous cytology was consistent with normal cycling in vehicle rats and halting of normal cycling in EE and LEVO rats. EE increased uterine weights consistent with typical uterotrophic effects observed with estrogens, further confirming the physiological impacts of our EE and LEVO doses. In conclusion, a physiologically effective dose of neither EE nor LEVO did not alter the reinforcing efficacy of a visual stimulus reinforcer. Future research should characterize the effects of hormonal contraceptives on responding maintained by other reinforcer types to determine the generality of the present findings.
Collapse
Affiliation(s)
- Kathleen R McNealy
- University of Nebraska-Lincoln, Department of Psychology, 238 Burnett Hall, Lincoln, NE 68588, USA.
| | - Matthew W Oevermann
- University of Nebraska-Lincoln, Department of Psychology, 238 Burnett Hall, Lincoln, NE 68588, USA
| | - MacKenzie L Knabel
- University of Nebraska-Lincoln, Department of Psychology, 238 Burnett Hall, Lincoln, NE 68588, USA
| | - Anna Fitzwater
- University of Nebraska-Lincoln, Institutional Animal Care Program, 2200 Vine Street, 278 Prem S. Paul Research Center at Whittier School, Lincoln, NE 68583, USA
| | - Cassandra D Gipson
- University of Kentucky, Department of Pharmacology and Nutrition Sciences, 780 Rose Street, MS305, Lexington, KY 40536, USA
| | - Scott T Barrett
- University of Nebraska-Lincoln, Department of Psychology, 238 Burnett Hall, Lincoln, NE 68588, USA
| | - Rick A Bevins
- University of Nebraska-Lincoln, Department of Psychology, 238 Burnett Hall, Lincoln, NE 68588, USA
| |
Collapse
|
2
|
Klappenbach CM, Wang Q, Jensen AL, Glodosky NC, Delevich K. Sex and timing of gonadectomy relative to puberty interact to influence weight, body composition, and feeding behaviors in mice. Horm Behav 2023; 151:105350. [PMID: 36996734 DOI: 10.1016/j.yhbeh.2023.105350] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 03/14/2023] [Accepted: 03/17/2023] [Indexed: 04/01/2023]
Abstract
Gonadal sex steroids are important regulators of energy balance in adult rodents, and gonadectomy (GDX) has opposing effects on weight gain in sexually mature males and females. Puberty is associated with the emergence of sex differences in weight, body composition, and feeding behaviors, yet the role of gonadal hormones at puberty remains unclear. To address this, we performed GDX or sham surgery in male and female C57Bl/6 mice at postnatal day (P)25 (prepubertal) or P60 (postpubertal) timepoints and measured weight and body composition for 35 days, after which ad libitum and operant food intake was measured using Feeding Experimentation Device 3 (FED3s) in the home cage. Consistent with previous studies, postpubertal GDX caused weight gain in females and weight loss in males and increased adiposity in both sexes. However, prepubertal GDX decreased weight gain and altered body composition across the adolescent transition (P25 to P60) in males but had no effect in females. Despite the varied effects on weight, GDX decreased food intake and motivation for food as assessed in operant tasks regardless of sex or timing of surgery relative to puberty. Our findings indicate that GDX interacts with both sex and age at surgery to influence weight, body composition, and feeding behavior.
Collapse
Affiliation(s)
- Courtney M Klappenbach
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| | - Qing Wang
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| | - Allison L Jensen
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA
| | - Nicholas C Glodosky
- Department of Psychology Washington State University, Pullman, WA 99164, USA
| | - Kristen Delevich
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA.
| |
Collapse
|
3
|
Smarr B, Rowland NE, Zucker I. Male and female mice show equal variability in food intake across 4-day spans that encompass estrous cycles. PLoS One 2019; 14:e0218935. [PMID: 31306437 PMCID: PMC6629064 DOI: 10.1371/journal.pone.0218935] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 06/04/2019] [Indexed: 11/19/2022] Open
Abstract
The exclusion of female rodents from biomedical research is well documented and persists in large part due to perceptions that ovulatory cycles render female traits more variable than those of males, and females must be tested at each of four stages of the estrous cycle to generate reliable data. These beliefs are not empirically based. The magnitude of trait variance associated with the estrous cycle may be sufficiently low and of little impact, or trait variability of males tested on 4 consecutive days may be as great as that of females over the 4 days of the estrous cycle. Here, we analyzed food intake data from mice in 4-day blocks, corresponding to the females' 4-day estrous cycle in several schedules of food procurement or reward. Variance was compared within and across individual mice. In no instance did the overall variance differ by sex under any of the food reward schedules. This extends earlier observations of trait variability in body temperature and locomotor activity of mice and supports the claim that there is no empirical basis for excluding female rodents from biomedical research.
Collapse
Affiliation(s)
- Benjamin Smarr
- Department of Psychology, University of California, Berkeley, United States of America
- * E-mail:
| | - Neil E. Rowland
- Department of Psychology, University of Florida, Gainesville, United States of America
| | - Irving Zucker
- Department of Psychology, University of California, Berkeley, United States of America
- Department of Integrative Biology, University of California, Berkeley, United States of America
| |
Collapse
|
4
|
Plessow F, Singhal V, Toth AT, Micali N, Eddy KT, Misra M. Estrogen administration improves the trajectory of eating disorder pathology in oligo-amenorrheic athletes: A randomized controlled trial. Psychoneuroendocrinology 2019; 102:273-280. [PMID: 30639922 PMCID: PMC6664444 DOI: 10.1016/j.psyneuen.2018.11.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 10/12/2018] [Accepted: 11/08/2018] [Indexed: 01/04/2023]
Abstract
OBJECTIVE Estrogen replacement prevents worsening body dissatisfaction with weight gain in adolescents with anorexia nervosa. However, the impact of estrogen administration on eating disorder (ED) pathology in normal-weight young women with exercise-induced amenorrhea is unknown. We hypothesized that (1) normal-weight oligo-amenorrheic athletes (OA) would show greater ED pathology than eumenorrheic athletes (EA) and non-athletes (NA), and (2) 12 months of estrogen replacement would improve those symptoms. TRIAL DESIGN Randomized trial. METHODS One hundred seventeen OA, 50 EA, and 41 NA completed the Eating Disorder Inventory-2 (EDI-2) for measures of Drive for Thinness (DT) and Body Dissatisfaction (BD) and the Three-Factor Eating Questionnaire-R18 (TFEQ-R18). OA were then randomized to receive 100 mcg transdermal 17β-estradiol with cyclic progesterone (PATCH), an oral contraceptive pill (30 mcg ethinyl estradiol + 0.15 mg desogestrel) (PILL), or no estrogen (E-) for 12 months. Data are reported for the subset that completed questionnaires at 0 and 12 months between 11/2009 and 10/2016. RESULTS OA showed higher EDI-2 DT and TFEQ-R18 Cognitive Restraint scores than EA and NA and higher EDI-2 BD scores than EA. Over 12 months, the E+ group (PATCH+PILL), compared to E-, showed improved trajectories for EDI-2 DT and BD scores. In 3-group comparisons, PATCH outperformed E- for decreases in EDI-2 DT and BD, and the PILL for TFEQ-R18 Uncontrolled Eating. CONCLUSION In OA, 12 months of estrogen replacement improves ED pathology trajectories, emphasizing the broad importance of normalizing estrogen levels. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov identifier: NCT00946192.
Collapse
Affiliation(s)
- Franziska Plessow
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| | - Vibha Singhal
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA,Division of Pediatric Endocrinology, Massachusetts General Hospital for Children and Harvard Medical School, Boston, MA, USA
| | - Alexander T. Toth
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Nadia Micali
- Child and Adolescent Psychiatry Division, Department of Psychiatry, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Kamryn T. Eddy
- Eating Disorders Clinical and Research Program, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Madhusmita Misra
- Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA,Division of Pediatric Endocrinology, Massachusetts General Hospital for Children and Harvard Medical School, Boston, MA, USA
| |
Collapse
|
5
|
Rowland NE, Atalayer D, Cervantez MR, Minaya DM, Splane EC. Cost-based anorexia: A novel framework to model anorexia nervosa. Appetite 2018; 130:50-58. [PMID: 30075177 DOI: 10.1016/j.appet.2018.07.034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 07/26/2018] [Accepted: 07/30/2018] [Indexed: 10/28/2022]
Abstract
Anorexia nervosa (AN) is an eating disorder that is thought to emerge through biological predisposition(s) within sociocultural context(s). Practical and ethical concerns limit study of the etiology of this disorder in humans, and in particular the biological aspects. Laboratory animal models have a pivotal role in advancing our understanding of the neurobiological, physiological and behavioral aspects of this disorder, and developing new treatment strategies. One shortcoming of animal models, including activity based anorexia (ABA) in rodents, is that they cannot fully capture the contextual aspects of AN. In this article we discuss the merits of an alternate approach, cost-based anorexia (CBA). CBA is conceptually founded in behavioral economics and its magnitude is influenced by several relevant contextual aspects of feeding.
Collapse
Affiliation(s)
- Neil E Rowland
- Department of Psychology, University of Florida, Gainesville, FL, 32611-2250, USA.
| | - Deniz Atalayer
- Department of Psychology, Sabancı University, Istanbul, Turkey
| | - Melissa R Cervantez
- Department of Psychology, University of Florida, Gainesville, FL, 32611-2250, USA
| | - Dulce M Minaya
- Department of Psychology, University of Florida, Gainesville, FL, 32611-2250, USA
| | - Emily C Splane
- Department of Social Sciences, Flagler College, St. Augustine, FL, USA
| |
Collapse
|
6
|
Rowland NE, Cervantez MR, Robertson KL. Temporal relationships between food acquisition and voluntary exercise in mice. Behav Processes 2017; 145:37-43. [PMID: 29017874 DOI: 10.1016/j.beproc.2017.09.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 09/05/2017] [Accepted: 09/28/2017] [Indexed: 01/13/2023]
Abstract
Patterns of operant food acquisition in a closed economy and bouts of either voluntary wheel running (WR) or spontaneous locomotor activity in a standard condition (SC) with no wheel were examined in young adult male and female C57BL/6 mice across a range of nose poke prices (FUP) per food pellet. Both sexes showed vigorous WR or locomotor activity. At each FUP, WR groups had higher food intake than SC groups. Despite substantially higher mean body weight of males compared with females, intakes and activity did not differ by sex in the SC groups and males lost weight more rapidly as FUP increased. In contrast, WR males ran ∼33% further per day than females, increased their food intake (above that of SC counterparts) more than females, and lost less body weight than SC males. By parsing the night in four 3h epochs it was found that food intake declined progressively through the night in both WR and SC mice and that the hyperphagia of WR relative to SC groups was most evident early in the night, coincident with highest activity. No large or systematic sex differences were revealed in these temporal analyses. Analysis of data at 60s resolution showed that pellet acquisition occurred in many small or short bouts, the timing of which was either intercalated or concurrent with either locomotor activity or WR. The results show that increased eating due to WR occurs concurrently with maximum running, and with no evidence of delayed compensation.
Collapse
Affiliation(s)
- Neil E Rowland
- University of Florida, Department of Psychology, Gainesville, United States.
| | | | | |
Collapse
|
7
|
Kyonka EGE, Subramaniam S, Bell-Garrison D, Eckard ML. Commentary “A Crisis in Comparative Psychology: Where have all the Undergraduates Gone?” Collaborating with Behavior Analysts Could Avert a Crisis in Comparative Psychology. Front Psychol 2015; 6:1743. [PMID: 26617562 PMCID: PMC4643129 DOI: 10.3389/fpsyg.2015.01743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 10/30/2015] [Indexed: 11/13/2022] Open
|