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Emser SV, Schaschl H, Millesi E, Steinborn R. Corrigendum: Extension of mitogenome enrichment based on single long-range PCR: mtDNAs and putative mitochondrial-derived peptides of five rodent hibernators. Front Genet 2024; 15:1386502. [PMID: 38533204 PMCID: PMC10963594 DOI: 10.3389/fgene.2024.1386502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 02/29/2024] [Indexed: 03/28/2024] Open
Abstract
[This corrects the article DOI: 10.3389/fgene.2021.685806.].
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Affiliation(s)
- Sarah V. Emser
- Genomics Core Facility, VetCore, University of Veterinary Medicine, Vienna, Austria
- Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
| | - Helmut Schaschl
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
| | - Eva Millesi
- Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
| | - Ralf Steinborn
- Genomics Core Facility, VetCore, University of Veterinary Medicine, Vienna, Austria
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2
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Nemeth M, Meidlinger B, Barnreiter E, Wallner B, Millesi E. Metabolic rates in female guinea pigs during different reproductive stages. ZOOLOGY 2023; 161:126132. [PMID: 37931560 DOI: 10.1016/j.zool.2023.126132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 10/26/2023] [Accepted: 10/28/2023] [Indexed: 11/08/2023]
Abstract
Reproduction in female mammals is characterized by major changes in steroid hormone concentrations, which can be linked to fluctuations in energy expenditure (EE). Estradiol and cortisol can increase EE and metabolic rates (MRs), but knowledge on MR changes during the estrous cycle and gestation is scarce for many species. This also applies to the domestic guinea pig, a species exhibiting an exceptional estrous cycle among rodents. In this study, MRs were measured through oxygen (O2) consumption in female guinea pigs during different reproductive stages. Mean O2 consumption over 2.5 h, resting metabolic rate (RMR, lowest and most stable O2 consumption over 3 min), body mass, fecal estrogen and progesterone, and saliva cortisol concentrations were measured in twelve female guinea pigs in a repeated measurements design during diestrus, estrus, and the second trimester of gestation. In estrus, body mass was significantly lower and estrogen and cortisol concentrations were significantly higher compared to diestrus and gestation. Mean O2 consumption and RMR both were significantly increased in estrus compared to diestrus. Additionally, a positive effect of body mass on MRs detected during diestrus and gestation was not found during estrus. Mean O2 consumption was also higher during gestation compared to diestrus, and a significant increase in cortisol concentrations during the 2.5-h MR measurement was recorded. The results indicate that estrus in guinea pigs is energetically demanding, which probably reflects catabolic effects of estrogens and cortisol that uncoupled MRs from body mass. Knowledge on the energetic requirements associated with different reproductive stages is important for future physiological and behavioral studies on female guinea pigs.
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Affiliation(s)
- Matthias Nemeth
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, University of Vienna Biology Building, Djerassiplatz 1, 1030 Vienna, Austria.
| | - Bettina Meidlinger
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, University of Vienna Biology Building, Djerassiplatz 1, 1030 Vienna, Austria
| | - Elisabeth Barnreiter
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, University of Vienna Biology Building, Djerassiplatz 1, 1030 Vienna, Austria
| | - Bernard Wallner
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, University of Vienna Biology Building, Djerassiplatz 1, 1030 Vienna, Austria
| | - Eva Millesi
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, University of Vienna Biology Building, Djerassiplatz 1, 1030 Vienna, Austria
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3
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Stocker M, O’Sullivan EP, Palme R, Millesi E, Sonnweber R. Measurement of Salivary Cortisol in Two New World Primate Species. Biology (Basel) 2023; 12:1181. [PMID: 37759581 PMCID: PMC10525777 DOI: 10.3390/biology12091181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 08/10/2023] [Accepted: 08/28/2023] [Indexed: 09/29/2023]
Abstract
Glucocorticoids (GCs) are mammalian steroid hormones involved in a variety of physiological processes, including metabolism, the immune response, and cardiovascular functions. Due to their link to the physiological stress response, GC measurement is a valuable tool for conservation and welfare assessment in animal populations. GC levels can be measured from different matrices, such as urine and feces. Moreover, especially in captive settings, measuring GCs from saliva samples proved particularly useful as those samples can be collected non-invasively and easily from trained animals. Salivary GC levels can be measured using a variety of analytical methods, such as enzyme immunoassays. However, it is crucial to validate the analytical method for each specific application and species when using a new matrix. Using high-pressure liquid chromatography and a cortisol enzyme immunoassay, we show that the main glucocorticoids secreted in the saliva of squirrel monkeys and brown capuchin monkeys are cortisol and cortisone. Our biological validation found the expected salivary cortisol level to decline throughout the day. Our findings support the reliability of salivary cortisol measurements and their potential to be used as a valid tool in research and welfare assessment for these non-human primates.
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Affiliation(s)
- Martina Stocker
- Animal Science Department, Biomedical Primate Research Centre, 2288 GJ Rijswijk, The Netherlands
- Department of Behavioral and Cognitive Biology, University of Vienna, 1030 Vienna, Austria
| | - Eoin P. O’Sullivan
- School of Psychology and Neuroscience, University of St Andrews, St Andrews KY16 9JP, UK
| | - Rupert Palme
- Unit of Physiology, Pathophysiology and Experimental Endocrinology, Department of Biomedical Sciences, University of Veterinary Medicine, 1210 Vienna, Austria
| | - Eva Millesi
- Department of Behavioral and Cognitive Biology, University of Vienna, 1030 Vienna, Austria
| | - Ruth Sonnweber
- Department of Behavioral and Cognitive Biology, University of Vienna, 1030 Vienna, Austria
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4
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Emser SV, Spielvogel CP, Millesi E, Steinborn R. Mitochondrial polymorphism m.3017C>T of SHLP6 relates to heterothermy. Front Physiol 2023; 14:1207620. [PMID: 37675281 PMCID: PMC10478271 DOI: 10.3389/fphys.2023.1207620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 07/31/2023] [Indexed: 09/08/2023] Open
Abstract
Heterothermic thermoregulation requires intricate regulation of metabolic rate and activation of pro-survival factors. Eliciting these responses and coordinating the necessary energy shifts likely involves retrograde signalling by mitochondrial-derived peptides (MDPs). Members of the group were suggested before to play a role in heterothermic physiology, a key component of hibernation and daily torpor. Here we studied the mitochondrial single-nucleotide polymorphism (SNP) m.3017C>T that resides in the evolutionarily conserved gene MT-SHLP6. The substitution occurring in several mammalian orders causes truncation of SHLP6 peptide size from twenty to nine amino acids. Public mass spectrometric (MS) data of human SHLP6 indicated a canonical size of 20 amino acids, but not the use of alternative translation initiation codons that would expand the peptide. The shorter isoform of SHLP6 was found in heterothermic rodents at higher frequency compared to homeothermic rodents (p < 0.001). In heterothermic mammals it was associated with lower minimal body temperature (T b, p < 0.001). In the thirteen-lined ground squirrel, brown adipose tissue-a key organ required for hibernation, showed dynamic changes of the steady-state transcript level of mt-Shlp6. The level was significantly higher before hibernation and during interbout arousal and lower during torpor and after hibernation. Our finding argues to further explore the mode of action of SHLP6 size isoforms with respect to mammalian thermoregulation and possibly mitochondrial retrograde signalling.
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Affiliation(s)
- Sarah V. Emser
- Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
- Genomics Core Facility, VetCore, University of Veterinary Medicine, Vienna, Austria
| | - Clemens P. Spielvogel
- Department of Biomedical Imaging and Image-Guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Eva Millesi
- Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
| | - Ralf Steinborn
- Genomics Core Facility, VetCore, University of Veterinary Medicine, Vienna, Austria
- Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna, Austria
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Siutz C, Nemeth M, Quint R, Wagner KH, Millesi E. PUFA changes in white adipose tissue during hibernation in common hamsters. Physiol Biochem Zool 2022; 95:525-535. [DOI: 10.1086/721444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Emser SV, Schaschl H, Millesi E, Steinborn R. Extension of Mitogenome Enrichment Based on Single Long-Range PCR: mtDNAs and Putative Mitochondrial-Derived Peptides of Five Rodent Hibernators. Front Genet 2021; 12:685806. [PMID: 35027919 PMCID: PMC8749263 DOI: 10.3389/fgene.2021.685806] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 11/10/2021] [Indexed: 12/14/2022] Open
Abstract
Enriching mitochondrial DNA (mtDNA) for sequencing entire mitochondrial genomes (mitogenomes) can be achieved by single long-range PCR. This avoids interference from the omnipresent nuclear mtDNA sequences (NUMTs). The approach is currently restricted to the use of samples collected from humans and ray-finned fishes. Here, we extended the use of single long-range PCR by introducing back-to-back oligonucleotides that target a sequence of extraordinary homology across vertebrates. The assay was applied to five hibernating rodents, namely alpine marmot, Arctic and European ground squirrels, and common and garden dormice, four of which have not been fully sequenced before. Analysis of the novel mitogenomes focussed on the prediction of mitochondrial-derived peptides (MDPs) providing another level of information encoded by mtDNA. The comparison of MOTS-c, SHLP4 and SHLP6 sequences across vertebrate species identified segments of high homology that argue for future experimentation. In addition, we evaluated four candidate polymorphisms replacing an amino acid in mitochondrially encoded subunits of the oxidative phosphorylation (OXPHOS) system that were reported in relation to cold-adaptation. No obvious pattern was found for the diverse sets of mammalian species that either apply daily or multiday torpor or otherwise cope with cold. In summary, our single long-range PCR assay applying a pair of back-to-back primers that target a consensus sequence motif of Vertebrata has potential to amplify (intact) mitochondrial rings present in templates from a taxonomically diverse range of vertebrates. It could be promising for studying novel mitogenomes, mitotypes of a population and mitochondrial heteroplasmy in a sensitive, straightforward and flexible manner.
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Affiliation(s)
- Sarah V. Emser
- Genomics Core Facility, VetCore, University of Veterinary Medicine, Vienna, Austria
- Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
| | - Helmut Schaschl
- Department of Evolutionary Anthropology, University of Vienna, Vienna, Austria
| | - Eva Millesi
- Department of Behavioral and Cognitive Biology, University of Vienna, Vienna, Austria
| | - Ralf Steinborn
- Genomics Core Facility, VetCore, University of Veterinary Medicine, Vienna, Austria
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7
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Siutz C, Ruf T, Monecke S, Millesi E. Morphometric parameters predict body fat proportions in common hamsters. J Mammal 2021; 103:471-480. [PMID: 35418810 PMCID: PMC8996034 DOI: 10.1093/jmammal/gyab137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 10/02/2021] [Indexed: 12/01/2022] Open
Abstract
Common hamsters (Cricetus cricetus) are hibernators that rely both on body fat reserves and food stores for the winter period. They face an ongoing population decline in most parts of their distribution and recently were classified as critically endangered. Knowledge on individual body fat proportions in this species is of particular interest for conservation, because it could contribute to better understand the high plasticity in overwintering strategies, overwinter mortality rates, individual variations in reproductive output, and give information on the animals’ health state. To calculate body fat proportions, we validated a method that can be applied in the field without the use of anesthesia. To develop this method, we first analyzed the body fat in carcasses of common hamsters using Soxhlet extractions and measured four morphometric parameters (body mass, head length, tibia length, foot length). The morphometric measurements were then integrated in a linear regression model to predict body fat proportions based on the measured values. The morphometric variables yielded an explained variance (adjusted R2) of 96.42% and body fat proportions were predicted with a mean absolute error of 1.27 ± 0.11% from measured values. We applied the model to predict body fat for available field data, which consistently produced reliable values. By measuring the four morphometric parameters and following the provided instructions, body fat proportions can be reliably and noninvasively estimated in captive or free-ranging common hamsters. Furthermore, the method could be applicable to other rodents after species-specific validation.
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Affiliation(s)
- Carina Siutz
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Thomas Ruf
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Savoyenstraße 1, 1160 Vienna, Austria
| | - Stefanie Monecke
- Institut des Neurosciences Cellulaires et Intégratives (INCI), Neurobiologie des Rythmes, CNRS UPR-3212, Université de Strasbourg, 8 allée du général Rouvillois, 67000 Strasbourg, France
- Institute of Medical Psychology, Medical Faculty, Ludwig-Maximilians-University Munich, Goethestrasse 31/ I, 80336 Munich, Germany
| | - Eva Millesi
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
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Nemeth M, Eisenschenk I, Engelmann A, Esser FM, Kokodynska M, Szewczak VF, Barnreiter E, Wallner B, Millesi E. Flaxseed oil as omega-3 polyunsaturated fatty acid source modulates cortisol concentrations and social dominance in male and female guinea pigs. Horm Behav 2021; 134:105025. [PMID: 34242874 DOI: 10.1016/j.yhbeh.2021.105025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 06/01/2021] [Accepted: 06/25/2021] [Indexed: 12/14/2022]
Abstract
Flaxseed oil is an excellent source of the essential omega-3 polyunsaturated fatty acid (PUFA) alpha-linolenic acid (ALA). Omega-3 PUFAs are important neuronal components and can counteract aggressive, depressive, and anxiety-like behavior, reduce glucocorticoid (e.g. cortisol) concentrations under chronic stress but also increase acute glucocorticoid responses. As glucocorticoids per se and glucocorticoid responsiveness can modulate the establishment of dominance hierarchies, we investigated if flaxseed oil high in ALA can promote social dominance through effects on glucocorticoid concentrations. Two male and two female groups of domestic guinea pigs (n = 9 per group) were maintained on a control or a 5% (w/w) flaxseed oil diet for four weeks. Social behaviors, hierarchy indices, locomotion, and saliva cortisol concentrations were determined during basal group housing conditions and stressful social confrontations with unfamiliar individuals of the other groups. Flaxseed groups had increased basal cortisol concentrations and showed no cortisol increase during social confrontations. Cortisol concentrations in control groups significantly increased during social confrontations. Such higher cortisol responses positively affected individual hierarchy indices in control males. However, flaxseed males became dominant irrespective of cortisol concentrations. In females, the opposite was detected, namely a higher dominant status in control compared to flaxseed females. Open-field- and dark-light-tests for anxiety-like behavior revealed no pronounced differences, but flaxseed males showed the highest locomotor activity. Flaxseed oil as an ALA source sex-specifically promoted social dominance irrespective of cortisol concentrations and responses. The underlying neuronal mechanisms remain to be determined, but a sex-specific energetic advantage may have accounted for this effect.
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Affiliation(s)
- Matthias Nemeth
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.
| | - Isabelle Eisenschenk
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Anna Engelmann
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Fey Maria Esser
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Michelle Kokodynska
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Veronika Francesca Szewczak
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Elisabeth Barnreiter
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Bernard Wallner
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Eva Millesi
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
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9
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Nemeth M, Wallner B, Schuster D, Siutz C, Quint R, Wagner KH, Millesi E. Effects of dietary fatty acids on the social life of male Guinea pigs from adolescence to adulthood. Horm Behav 2020; 124:104784. [PMID: 32504693 DOI: 10.1016/j.yhbeh.2020.104784] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 05/29/2020] [Accepted: 05/30/2020] [Indexed: 12/19/2022]
Abstract
Dietary intake of polyunsaturated fatty acids (PUFAs) or saturated fatty acids (SFAs) differently modulates neurophysiological and behavioral functions in response to altered hypothalamic-pituitary-adrenal (HPA)-axis activity and an individual's development. In this context, an individual's social environment, including social interactions and social hierarchies, is closely related to hormone concentrations and possibly interacts with dietary fatty acid effects. We investigated if dietary supplementation with walnut oil (high in PUFAs) and coconut fat (high in SFAs), compared to a control group, affects body mass gain, cortisol and testosterone concentrations, plasma fatty acids, and social behavior in male domestic guinea pigs from adolescence to adulthood. For analyses of cortisol and testosterone concentrations, social interactions were included as covariates in order to consider effects of social behavior on hormone concentrations. Our results revealed that SFAs increased escalated conflicts like fights and stimulated cortisol and testosterone concentrations, which limited body mass gain and first-year survival. PUFAs did not remarkably affect social behavior and hormone concentrations, but enabled the strongest body mass gain, which probably resulted from an energetic advantage. Neither sociopositive nor agonistic behaviors explained age-specific differences in hormone concentrations between groups. However, a high number of subdominant individuals and lower testosterone concentrations were related to increased cortisol concentrations in adult PUFA males. Our findings demonstrate the importance of dietary fatty acids regarding behavioral and endocrine developmental processes and adaptations to the social environment by modulating HPA-axis function and body homeostasis.
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Affiliation(s)
- Matthias Nemeth
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.
| | - Bernard Wallner
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Daniela Schuster
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Carina Siutz
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Ruth Quint
- Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Karl-Heinz Wagner
- Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Eva Millesi
- Department of Behavioral and Cognitive Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
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Flamand A, Rebout N, Bordes C, Guinnefollau L, Bergès M, Ajak F, Siutz C, Millesi E, Weber C, Petit O. Hamsters in the city: A study on the behaviour of a population of common hamsters (Cricetus cricetus) in urban environment. PLoS One 2019; 14:e0225347. [PMID: 31751416 PMCID: PMC6872164 DOI: 10.1371/journal.pone.0225347] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 11/01/2019] [Indexed: 11/18/2022] Open
Abstract
Animals in urban environments face challenging situations and have to cope with human activities. This study investigated the ecology and behaviour of a population of European hamsters (Cricetus cricetus) living in the city centre of Vienna (Austria). We recorded the surface activities of 35 hamsters in May 2015. Each focal animal was observed for 15 minutes, and a total of 66 focal samples were analysable. As a prey species in an environment teeming with human activities, we predicted a high level of vigilance by the hamsters. The results show that while animals dedicated a lot of time to vigilance, most of their time was spent foraging. The study also explores whether the frequency of vigilance behaviours differ between males and females. We found that vigilance behaviours were expressed in a different manner by males and females. Finally, we investigated the distribution of the burrows on green spaces depending on proximity to trees and on noise levels. We found a biased distribution of burrows, with a spatial preference for location protected by the vegetation and distant to noise sources. Although burrows were located preferentially under vegetation cover, levels of noise did not determine their positions. Moreover, this species does not respond to disturbances like daily urban noises, probably due to habituation. The common hamster is an endangered species; our results lead to a greater knowledge of its behaviour in a persistent urban population.
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Affiliation(s)
- Anna Flamand
- Laboratoire Image Ville Environnement, UMR 7362, Faculté de Géographie et de l’aménagement, Strasbourg, France
- Cognitive and Social Ethology Group, UMR Physiologie de la Reproduction et des Comportements, CNRS, IFCE, INRA, Université de Tours, Nouzilly, France
| | - Nancy Rebout
- Cognitive and Social Ethology Group, UMR Physiologie de la Reproduction et des Comportements, CNRS, IFCE, INRA, Université de Tours, Nouzilly, France
| | - Camille Bordes
- Ecole Nationale Supérieure Agronomique de Toulouse, Castanet-Tolosan Cedex, France
| | | | | | - Fanny Ajak
- IPHC- DEPE, UMR 7178, Université de Strasbourg-CNRS, Strasbourg Cedex 2, France
| | - Carina Siutz
- Department of Behavioural Biology, University of Vienna, Althanstrasse, Vienna, Austria
| | - Eva Millesi
- Department of Behavioural Biology, University of Vienna, Althanstrasse, Vienna, Austria
| | | | - Odile Petit
- Cognitive and Social Ethology Group, UMR Physiologie de la Reproduction et des Comportements, CNRS, IFCE, INRA, Université de Tours, Nouzilly, France
- * E-mail:
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Naber A, Kreuzer L, Zink R, Millesi E, Palme R, Hediger K, Glenk LM. Heart rate, heart rate variability and salivary cortisol as indicators of arousal and synchrony in clients with intellectual disability, horses and therapist during equine-assisted interventions. Pet Behav Sci 2019. [DOI: 10.21071/pbs.v0i7.11801] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The aim of the study was to analyse interaction processes in equine-assisted therapy (EAT) sessions with ten female clients in the period of emerging adulthood with intellectual disability (ID). Heart rate (HR), heart rate variability and salivary cortisol levels have been analysed in humans and horses before, during and after a standardised therapy session as well as in a control condition. There was a trend of lower cortisol levels and higher variability and parasympathetic tone induced by horses. During challenge however, there was a significant lower HR in the horse condition. Significant correlations in heart rate between therapist, client and horse were found with stronger interaction with a familiar horse. Our findings suggest that EAT may effectively modulate stress in humans with ID. Our results further elucidate synchronisation patterns in HR highlighting the pivotal role of relationship quality and intensity as modulators of synchrony.
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12
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Wallner B, Windhager S, Schaschl H, Nemeth M, Pflüger LS, Fieder M, Domjanić J, Millesi E, Seidler H. Sexual Attractiveness: a Comparative Approach to Morphological, Behavioral and Neurophysiological Aspects of Sexual Signaling in Women and Nonhuman Primate Females. Adaptive Human Behavior and Physiology 2019. [DOI: 10.1007/s40750-019-00111-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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13
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Scheiber IBR, Weiß BM, de Jong ME, Braun A, van den Brink NW, Loonen MJJE, Millesi E, Komdeur J. Stress behaviour and physiology of developing Arctic barnacle goslings ( Branta leucopsis) is affected by legacy trace contaminants. Proc Biol Sci 2018; 285:20181866. [PMID: 30963902 PMCID: PMC6304058 DOI: 10.1098/rspb.2018.1866] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 11/12/2018] [Indexed: 11/23/2022] Open
Abstract
Natural populations are persistently exposed to environmental pollution, which may adversely impact animal physiology and behaviour and even compromise survival. Responding appropriately to any stressor ultimately might tip the scales for survival, as mistimed behaviour and inadequate physiological responses may be detrimental. Yet effects of legacy contamination on immediate physiological and behavioural stress coping abilities during acute stress are virtually unknown. Here, we assessed these effects in barnacle goslings ( Branta leucopsis) at a historical coal mine site in the Arctic. For three weeks we led human-imprinted goslings, collected from nests in unpolluted areas, to feed in an abandoned coal mining area, where they were exposed to trace metals. As control we led their siblings to feed on clean grounds. After submitting both groups to three well-established stress tests (group isolation, individual isolation, on-back restraint), control goslings behaved calmer and excreted lower levels of corticosterone metabolites. Thus, legacy contamination may decisively change stress physiology and behaviour in long-lived vertebrates exposed at a young age.
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Affiliation(s)
- Isabella B. R. Scheiber
- Behavioural and Physiological Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands
- Department of Behavioural Biology, Faculty of Life Sciences, University of Vienna, 1090 Vienna, Austria
| | - Brigitte M. Weiß
- Behavioural Ecology Research Group, University of Leipzig, 04103 Leipzig, Germany
- Department of Primatology, Max Planck Institute for Evolutionary Anthropology, 04103 Leipzig, Germany
| | - Margje E. de Jong
- Arctic Centre, University of Groningen, 9718 CW Groningen, The Netherlands
| | - Anna Braun
- Behavioural and Physiological Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Nico W. van den Brink
- Department of Toxicology, Wageningen University, 6700 EA Wageningen, The Netherlands
| | | | - Eva Millesi
- Department of Behavioural Biology, Faculty of Life Sciences, University of Vienna, 1090 Vienna, Austria
| | - Jan Komdeur
- Behavioural and Physiological Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9747 AG Groningen, The Netherlands
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Siutz C, Ammann V, Millesi E. Shallow Torpor Expression in Free-Ranging Common Hamsters With and Without Food Supplements. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00190] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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15
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Siutz C, Valent M, Ammann V, Niebauer A, Millesi E. Sex-specific effects of food supplementation on hibernation performance and reproductive timing in free-ranging common hamsters. Sci Rep 2018; 8:13082. [PMID: 30166598 PMCID: PMC6117252 DOI: 10.1038/s41598-018-31520-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/20/2018] [Indexed: 02/03/2023] Open
Abstract
Hibernation is characterized by reduced metabolism and body temperature during torpor bouts. Energy reserves available during winter play an important role for hibernation and some species respond to high energy reserves with reduced torpor expression. Common hamsters are food-storing hibernators and females hibernate for shorter periods than males, probably related to larger food stores. In this study, we provided free-ranging common hamsters with sunflower seeds shortly before winter and recorded body temperature using subcutaneously implanted data loggers. We compared hibernation patterns and body mass changes between individuals with and without food supplements and analysed reproductive onset in females. Supplemented males delayed hibernation onset, hibernated for much shorter periods, and emerged in spring with higher body mass than unsupplemented ones. Additional food did not affect hibernation performance in females, but supplemented females emerged earlier and preceded those without food supplements in reproductive onset. Thus, males and females differently responded to food supplementation: access to energy-rich food stores enabled males to shorten the hibernation period and emerge in better body condition, probably enhancing mating opportunities and reproductive success. Females did not alter hibernation patterns, but started to reproduce earlier than unsupplemented individuals, enabling reproductive benefits by an extended breeding period.
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Affiliation(s)
- Carina Siutz
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria.
| | - Margit Valent
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Viktoria Ammann
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Ariane Niebauer
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Eva Millesi
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
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Roswag A, Becker NI, Millesi E, Otto MS, Ruoss S, Sander M, Siutz C, Weinhold U, Encarnação JA. Stable isotope analysis as a minimal-invasive method for dietary studies on the highly endangered Common hamster (Cricetus cricetus). MAMMALIA 2018. [DOI: 10.1515/mammalia-2017-0097] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
This study applied the analysis of stable isotope ratios as a minimally-invasive tool to estimate the diet of Cricetus cricetus for the first time. We took hair and food samples of three different populations of C. cricetus and analyzed stable carbon and nitrogen ratios. The stable isotope ratios in hamster hairs differed significantly within and between populations according to different sampling seasons and animal ages. Additionally, the isotopic signatures of potential food samples differed between sampling sites and food categories. The isotopic mixing models illustrated that diet composition varied with season and food availability. During the summer season hamsters living in agricultural areas mainly fed on green and ripe crop. In contrast to this, during the winter season ripe crop was the main food component for hamsters in agricultural areas while hamsters living in urban areas fed almost exclusively on nuts. These are, despite a wide variety of available food sources, most suitable for hoarding in the burrow. We conclude that stable isotope analysis of hamster hairs is an appropriate minimal-invasive method to investigate correlations between available and consumed food sources throughout the overall distribution of this species.
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Affiliation(s)
- Anna Roswag
- Mammalian Ecology Group , Department of Animal Ecology and Systematics , Justus-Liebig-University of Giessen, Heinrich-Buff-Ring 26 (IFZ) , 35392 Gießen , Germany
| | - Nina I. Becker
- Mammalian Ecology Group , Department of Animal Ecology and Systematics , Justus-Liebig-University of Giessen, Heinrich-Buff-Ring 26 (IFZ) , 35392 Gießen , Germany
- inatu.re, Institute for Applied Animal Ecology and Ecoinformatics, Im Brühl 2 , 35457 Lollar , Germany
| | - Eva Millesi
- Department of Behavioural Biology , University of Vienna, Althanstrasse 14 , 1090 Vienna , Austria
| | - Matthias S. Otto
- Mammalian Ecology Group , Department of Animal Ecology and Systematics , Justus-Liebig-University of Giessen, Heinrich-Buff-Ring 26 (IFZ) , 35392 Gießen , Germany
| | - Sara Ruoss
- Mammalian Ecology Group , Department of Animal Ecology and Systematics , Justus-Liebig-University of Giessen, Heinrich-Buff-Ring 26 (IFZ) , 35392 Gießen , Germany
| | - Marco Sander
- Institute for Faunistics, Silberne Bergstr. 24 , 69253 Heiligkreuzsteinach , Germany
| | - Carina Siutz
- Department of Behavioural Biology , University of Vienna, Althanstrasse 14 , 1090 Vienna , Austria
| | - Ulrich Weinhold
- Institute for Faunistics, Silberne Bergstr. 24 , 69253 Heiligkreuzsteinach , Germany
| | - Jorge A. Encarnação
- Mammalian Ecology Group , Department of Animal Ecology and Systematics , Justus-Liebig-University of Giessen, Heinrich-Buff-Ring 26 (IFZ) , 35392 Gießen , Germany
- inatu.re, Institute for Applied Animal Ecology and Ecoinformatics, Im Brühl 2 , 35457 Lollar , Germany
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17
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Nemeth M, Wallner B, Siutz C, Pschernig E, Wagner KH, Millesi E. Steroid hormone concentrations and body mass are differently affected by polyunsaturated fatty acids during the oestrous cycle in guinea pigs. Reprod Fertil Dev 2018; 30:1077-1086. [PMID: 29306361 DOI: 10.1071/rd17242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 12/04/2017] [Indexed: 11/23/2022] Open
Abstract
Reproductive functions in female mammals can be significantly affected by the actions of dietary polyunsaturated fatty acids (PUFAs) on steroid hormone secretion rates. Nevertheless, the effects of plasma free PUFAs on the oestrous cycle have seldom been considered. Therefore, in the present study, the diet of domestic guinea pigs was supplemented with high concentrations of different PUFAs and the effects of altered plasma PUFA patterns on steroid hormone concentrations, measured non-invasively, and body mass during oestrus and dioestrus were analysed. The oestrous cycle was characterised by increased oestrogen and cortisol concentrations in oestrus, corroborated by lowest bodyweight, whereas progesterone concentrations were highest in dioestrus. Plasma concentrations of the long-chain PUFAs docosahexaenoic acid (DHA; 22:6 ω3) and arachidonic acid (AA; 20:5 ω6) affected steroid hormone concentrations differently in oestrus and dioestrus. DHA positively affected oestrogen and progesterone concentrations and diminished cortisol concentrations only in oestrus. In contrast, AA negatively affected oestrogen and stimulated cortisol concentrations in oestrus and reduced progesterone concentrations in general. These findings imply selective and opposite contributions of DHA and AA to ovarian functions during different stages of the oestrous cycle, indicating a high biological relevance of plasma free PUFAs in female reproductive function.
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Affiliation(s)
- Matthias Nemeth
- Department of Behavioural Biology, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria
| | - Bernard Wallner
- Department of Behavioural Biology, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria
| | - Carina Siutz
- Department of Behavioural Biology, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria
| | - Elisabeth Pschernig
- Department of Behavioural Biology, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria
| | - Karl-Heinz Wagner
- Department of Nutritional Sciences, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria
| | - Eva Millesi
- Department of Behavioural Biology, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria
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18
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Siutz C, Nemeth M, Wagner KH, Quint R, Ruf T, Millesi E. Effects of food store quality on hibernation performance in common hamsters. PLoS One 2017; 12:e0185913. [PMID: 29045417 PMCID: PMC5646777 DOI: 10.1371/journal.pone.0185913] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Accepted: 09/21/2017] [Indexed: 11/18/2022] Open
Abstract
Hibernating animals can adjust torpor expression according to available energy reserves. Besides the quantity, the quality of energy reserves could play an important role for overwintering strategies. Common hamsters are food-storing hibernators and show high individual variation in hibernation performance, which might be related to the quality of food hoards in the hibernacula. In this study, we tested the effects of food stores high in fat content, particularly polyunsaturated fatty acids (PUFAs), on hibernation patterns under laboratory conditions. Control animals received standard rodent pellets only, while in the other group pellets were supplemented with sunflower seeds. We recorded body temperature during winter using subcutaneously implanted data loggers, documented total food consumption during winter, and analysed PUFA proportions in white adipose tissue (WAT) before and after the winter period. About half of the individuals in both groups hibernated and torpor expression did not differ between these animals. Among the high-fat group, however, individuals with high sunflower seeds intake strongly reduced the time spent in deep torpor. PUFA proportions in WAT decreased during winter in both groups and this decline was positively related to the time an individual spent in deep torpor. Sunflower seeds intake dampened the PUFA decline resulting in higher PUFA levels in animals of the high-fat group after winter. In conclusion, our results showed that common hamsters adjusted torpor expression and food intake in relation to the total energy of food reserves, underlining the importance of food hoard quality on hibernation performance.
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Affiliation(s)
- Carina Siutz
- Department of Behavioural Biology, Faculty of Life Sciences, University of Vienna, Vienna, Austria
- * E-mail:
| | - Matthias Nemeth
- Department of Behavioural Biology, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Karl-Heinz Wagner
- Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Ruth Quint
- Department of Nutritional Sciences, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Thomas Ruf
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Eva Millesi
- Department of Behavioural Biology, Faculty of Life Sciences, University of Vienna, Vienna, Austria
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19
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Nemeth M, Millesi E, Siutz C, Wagner KH, Quint R, Wallner B. Reproductive performance and gestational effort in relation to dietary fatty acids in guinea pigs. J Anim Sci Biotechnol 2017; 8:28. [PMID: 28373905 PMCID: PMC5376286 DOI: 10.1186/s40104-017-0158-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 03/14/2017] [Indexed: 11/29/2022] Open
Abstract
Background Dietary saturated (SFAs) and polyunsaturated (PUFAs) fatty acids can highly affect reproductive functions by providing additional energy, modulating the biochemical properties of tissues, and hormone secretions. In precocial mammals such as domestic guinea pigs the offspring is born highly developed. Gestation might be the most critical reproductive period in this species and dietary fatty acids may profoundly influence the gestational effort. We therefore determined the hormonal status at conception, the reproductive success, and body mass changes during gestation in guinea pigs maintained on diets high in PUFAs or SFAs, or a control diet. Results The diets significantly affected the females’ plasma fatty acid status at conception, while cortisol and estrogen levels did not differ among groups. SFA females exhibited a significantly lower body mass and litter size, while the individual birth mass of pups did not differ among groups and a general higher pup mortality rate in larger litters was diminished by PUFAs and SFAs. The gestational effort, determined by a mother’s body mass gain during gestation, increased with total litter mass, whereas this increase was lowest in SFA and highest in PUFA individuals. The mother’s body mass after parturition did not differ among groups and was positively affected by the total litter mass in PUFA females. Conclusions While SFAs reduce the litter size, but also the gestational effort as a consequence, PUFA supplementation may contribute to an adjustment of energy accumulations to the total litter mass, which may both favor a mother’s body condition at parturition and perhaps increase the offspring survival at birth. Electronic supplementary material The online version of this article (doi:10.1186/s40104-017-0158-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Matthias Nemeth
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Eva Millesi
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Carina Siutz
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Karl-Heinz Wagner
- Department of Nutritional Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Ruth Quint
- Department of Nutritional Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Bernard Wallner
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.,Department of Anthropology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
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20
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Windhager S, Bookstein FL, Millesi E, Wallner B, Schaefer K. Patterns of correlation of facial shape with physiological measurements are more integrated than patterns of correlation with ratings. Sci Rep 2017; 7:45340. [PMID: 28349947 PMCID: PMC5368612 DOI: 10.1038/srep45340] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 02/27/2017] [Indexed: 11/30/2022] Open
Abstract
This article exploits a method recently incorporated in the geometric morphometric toolkit that complements previous approaches to quantifying the facial features associated with specific body characteristics and trait attribution during social perception. The new method differentiates more globally encoded from more locally encoded information by a summary scaling dimension that is estimated by fitting a line to the plot of log bending energy against log variance explained, partial warp by partial warp, for some sample of varying shapes. In the present context these variances come from the regressions of shape on some exogenous cause or effect of form. We work an example involving data from male faces. Here the regression slopes are steepest, and the sums of explained variances over the uniform component, partial warp 1 and partial warp 2 are greatest, for the conventional body mass index, followed by cortisol and, lastly, perceived health. This suggests that physiological characteristics may be represented at larger scale (global patterns), whereas cues in perception are of smaller scale (local patterns). Such a polarity within psychomorphospace, the global versus the focal, now has a metric by which patterns of morphology can be modeled in both biological and psychological studies.
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Affiliation(s)
- S Windhager
- Department of Anthropology, University of Vienna, Althanstrasse 14, 1090 Wien, Austria.,Department of Theoretical Biology, University of Vienna, Althanstrasse 14, 1090 Wien, Austria
| | - F L Bookstein
- Department of Anthropology, University of Vienna, Althanstrasse 14, 1090 Wien, Austria.,Department of Statistics, University of Washington, Box 354322, Seattle, WA 98195-4322, USA
| | - E Millesi
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090 Wien, Austria
| | - B Wallner
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090 Wien, Austria
| | - K Schaefer
- Department of Anthropology, University of Vienna, Althanstrasse 14, 1090 Wien, Austria
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21
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Nemeth M, Millesi E, Puehringer-Sturmayr V, Kaplan A, Wagner KH, Quint R, Wallner B. Sex-specific effects of dietary fatty acids on saliva cortisol and social behavior in guinea pigs under different social environmental conditions. Biol Sex Differ 2016; 7:51. [PMID: 27688870 PMCID: PMC5034672 DOI: 10.1186/s13293-016-0107-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 09/13/2016] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Unbalanced dietary intakes of saturated (SFAs) and polyunsaturated (PUFAs) fatty acids can profoundly influence the hypothalamic-pituitary-adrenal (HPA)-axis and glucocorticoid secretions in relation to behavioral performances. The beneficial effects of higher dietary PUFA intakes and PUFA:SFA ratios may also affect social interactions and social-living per se, where adequate physiological and behavioral responses are essential to cope with unstable social environmental conditions. METHODS Effects of diets high in PUFAs or SFAs and a control diet were investigated in male and female guinea pigs after 60 days of supplementation. Plasma fatty acid patterns served as an indicator of the general fatty acid status. HPA-axis activities, determined by measuring saliva cortisol concentrations, social behaviors, and hierarchy ranks were analyzed during group housing of established single-sexed groups and during challenging social confrontations with unfamiliar individuals of the other groups. RESULTS The plasma PUFA:SFA ratio was highest in PUFA supplemented animals, with female levels significantly exceeding males, and lowest in SFA animals. SFA males and females showed increased saliva cortisol levels and decreased aggressiveness during group housing, while sociopositive behaviors were lowest in PUFA males. Males generally showed higher cortisol increases in response to the challenging social confrontations with unfamiliar individuals than females. While increasing cortisol concentrations were detected in control and PUFA animals, no such effect was found in SFA animals. During social confrontations, PUFA males showed higher levels of agonistic and sociopositive behaviors and also gained higher dominance ranks among males, which was not detected for females. CONCLUSIONS While SFAs seemingly impaired cortisol responses and social behaviors, PUFAs enabled adequate behavioral responses in male individuals under stressful new social environmental conditions. This sex-specific effect was possibly related to a general sex difference in the n-3 PUFA bioavailability and cortisol responses, which may indicate that males are more susceptible to changing environmental conditions, and shows how dietary fatty acids can shape social systems.
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Affiliation(s)
- Matthias Nemeth
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Eva Millesi
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | | | - Arthur Kaplan
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Karl-Heinz Wagner
- Department of Nutritional Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Ruth Quint
- Department of Nutritional Sciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Bernard Wallner
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
- Department of Anthropology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
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Siutz C, Franceschini C, Millesi E. Sex and age differences in hibernation patterns of common hamsters: adult females hibernate for shorter periods than males. J Comp Physiol B 2016; 186:801-11. [PMID: 27138337 PMCID: PMC4933728 DOI: 10.1007/s00360-016-0995-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 04/18/2016] [Accepted: 04/23/2016] [Indexed: 11/04/2022]
Abstract
In this study, we investigated the timing and duration of hibernation as well as body temperature patterns in free-ranging common hamsters (Cricetus cricetus) with regard to sex and age differences. Body temperature was recorded using subcutaneously implanted data loggers. The results demonstrate that although immergence and vernal emergence sequences of sex and age groups resembled those of most hibernators, particularly adult females delayed hibernation onset until up to early January. Thus, in contrast to other hibernators, female common hamsters hibernated for shorter periods than males and correspondingly spent less time in torpor. These sex differences were absent in juvenile hamsters. The period between the termination of hibernation and vernal emergence varied among individuals but did not differ between the sex and age groups. This period of preemergence euthermy was related to emergence body mass: individuals that terminated hibernation earlier in spring and had longer euthermic phases prior to emergence started the active season in a better condition. In addition, males with longer periods of preemergence euthermy had larger testes at emergence. In conclusion, females have to rely on sufficient food stores but may adjust the use of torpor in relation to the available external energy reserves, whereas males show a more pronounced energy-saving strategy by hibernating for longer periods. Nonetheless, food caches seem to be important for both males and females as indicated by the euthermic preemergence phase and the fact that some individuals, mainly yearlings, emerged with a higher body mass than shortly before immergence in autumn.
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Affiliation(s)
- Carina Siutz
- Department of Behavioral Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria.
| | - Claudia Franceschini
- Department of Behavioral Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Eva Millesi
- Department of Behavioral Biology, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
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Nemeth M, Pschernig E, Wallner B, Millesi E. Non-invasive cortisol measurements as indicators of physiological stress responses in guinea pigs. PeerJ 2016; 4:e1590. [PMID: 26839750 PMCID: PMC4734438 DOI: 10.7717/peerj.1590] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 12/21/2015] [Indexed: 12/19/2022] Open
Abstract
Non-invasive measurements of glucocorticoid (GC) concentrations, including cortisol and corticosterone, serve as reliable indicators of adrenocortical activities and physiological stress loads in a variety of species. As an alternative to invasive analyses based on plasma, GC concentrations in saliva still represent single-point-of-time measurements, suitable for studying short-term or acute stress responses, whereas fecal GC metabolites (FGMs) reflect overall stress loads and stress responses after a species-specific time frame in the long-term. In our study species, the domestic guinea pig, GC measurements are commonly used to indicate stress responses to different environmental conditions, but the biological relevance of non-invasive measurements is widely unknown. We therefore established an experimental protocol based on the animals' natural stress responses to different environmental conditions and compared GC levels in plasma, saliva, and fecal samples during non-stressful social isolations and stressful two-hour social confrontations with unfamiliar individuals. Plasma and saliva cortisol concentrations were significantly increased directly after the social confrontations, and plasma and saliva cortisol levels were strongly correlated. This demonstrates a high biological relevance of GC measurements in saliva. FGM levels measured 20 h afterwards, representing the reported mean gut passage time based on physiological validations, revealed that the overall stress load was not affected by the confrontations, but also no relations to plasma cortisol levels were detected. We therefore measured FGMs in two-hour intervals for 24 h after another social confrontation and detected significantly increased levels after four to twelve hours, reaching peak concentrations already after six hours. Our findings confirm that non-invasive GC measurements in guinea pigs are highly biologically relevant in indicating physiological stress responses compared to circulating levels in plasma in the short- and long-term. Our approach also underlines the importance of detailed investigations on how to use and interpret non-invasive measurements, including the determination of appropriate time points for sample collections.
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Affiliation(s)
- Matthias Nemeth
- Department of Behavioural Biology, University of Vienna , Vienna , Austria
| | | | - Bernard Wallner
- Department of Behavioural Biology, University of Vienna, Vienna, Austria; Department of Anthropology, University of Vienna, Vienna, Austria
| | - Eva Millesi
- Department of Behavioural Biology, University of Vienna , Vienna , Austria
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Gratzer B, Millesi E, Walzl M, Herler J. Skin toxins in coral-associated Gobiodon species (Teleostei: Gobiidae) affect predator preference and prey survival. Mar Ecol (Berl) 2015; 36:67-76. [PMID: 26074654 PMCID: PMC4459215 DOI: 10.1111/maec.12117] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 08/24/2013] [Indexed: 06/04/2023]
Abstract
Predation risk is high for the many small coral reef fishes, requiring successful sheltering or other predator defence mechanisms. Coral-dwelling gobies of the genus Gobiodon live in close association with scleractinian corals of the genus Acropora. Earlier studies indicated that the low movement frequency of adult fishes and the development of skin toxins (crinotoxicity) are predation avoidance mechanisms. Although past experiments showed that predators refuse food prepared with goby skin mucus, direct predator-prey interactions have not been studied. The present study compares the toxicity levels of two crinotoxic coral gobies - Gobiodon histrio, representative of a conspicuously coloured species, and Gobiodon sp.3 with cryptic coloration - using a standard bioassay method. The results show that toxin levels of both species differ significantly shortly after mucus release but become similar over time. Predator preferences were tested experimentally in an aquarium in which the two gobies and a juvenile damselfish Chromis viridis were exposed to the small grouper Epinephelus fasciatus. Video-analysis revealed that although coral gobies are potential prey, E. fasciatus clearly preferred the non-toxic control fish (C. viridis) over Gobiodon. When targeting a goby, the predator did not prefer one species over the other. Contrary to our expectations that toxic gobies are generally avoided, gobies were often captured, but they were expelled quickly, repeatedly and alive. This unusual post-capture avoidance confirms that these gobies have a very good chance of surviving attacks in the field due to their skin toxins. Nonetheless, some gobies were consumed: the coral shelter may therefore also provide additional protection, with toxins protecting them mainly during movement between corals. In summary, chemical deterrence by crinotoxic fishes seems to be far more efficient in predation avoidance than in physical deterrence involving body squamation and/or strong fin spines.
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Affiliation(s)
- Barbara Gratzer
- Department of Integrative Zoology, University of ViennaVienna, Austria
| | - Eva Millesi
- Department of Ethology, University of ViennaVienna, Austria
| | - Manfred Walzl
- Department of Integrative Zoology, University of ViennaVienna, Austria
| | - Juergen Herler
- Department of Integrative Zoology, University of ViennaVienna, Austria
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Nemeth M, Millesi E, Wagner KH, Wallner B. Effects of diets high in unsaturated Fatty acids on socially induced stress responses in Guinea pigs. PLoS One 2014; 9:e116292. [PMID: 25551380 PMCID: PMC4281161 DOI: 10.1371/journal.pone.0116292] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Accepted: 12/06/2014] [Indexed: 02/01/2023] Open
Abstract
Unsaturated fatty acids (UFAs), such as omega-3 and omega-6 poly- and omega-9 monounsaturated fatty acids are important nutrients and major components of neuronal cell membranes. They play a major role in modulating brain functions and physiology and may therefore diminish behavioral and physiological stress reactions in corroboration with decreased cortisol concentrations. Functionally, cortisol itself can modulate several behaviors and also the fatty acid metabolism in the long term. But only little is known about the behavioral and physiological influences of dietary UFAs in a social group, where individuals are regularly exposed to stressful situations. Therefore, the aim of this study was to determine the effects of dietary UFAs on saliva cortisol concentrations and behavioral responses in socially confronted guinea pigs. Three groups of animals were additionally supplemented with 500 mg chia seeds (high in omega-3), walnuts (high in omega-6), or peanuts (high in omega-9) per kg bodyweight each day and compared to a control group. During social confrontation saliva cortisol concentrations significantly increased in all groups, which was accompanied by a loss in bodyweight. However, cortisol levels remained lower in the chia and walnut groups compared to controls. Additionally, the walnut group displayed significantly increased locomotion, while no differences between groups were detected in socio-positive, sexual, or aggressive behaviors. Total plasma omega-3, omega-6, and omega-9 fatty acids were significantly increased in the corresponding groups, due to the dietary supplementations. However, a significant decrease in plasma omega-3 and an increase in plasma n-6 fatty acids were detected in the chia group when comparing the measurements before and after social confrontation. We conclude that both omega-3 and omega-6 polyunsaturated fatty acids can diminish behavioral and physiological stress responses to the social environment, enabling individuals to cope with social stressors, but at the expense of plasma derived omega-3 fatty acids.
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Affiliation(s)
- Matthias Nemeth
- Department of Behavioural Biology, University of Vienna, Vienna, Austria
| | - Eva Millesi
- Department of Behavioural Biology, University of Vienna, Vienna, Austria
| | - Karl-Heinz Wagner
- Department of Nutritional Science, University of Vienna, Vienna, Austria
| | - Bernard Wallner
- Department of Behavioural Biology, University of Vienna, Vienna, Austria
- Cognitive Science Research Platform, University of Vienna, Vienna, Austria
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Zöttl M, Lienert R, Clutton-Brock T, Millesi E, Manser MB. The effects of recruitment to direct predator cues on predator responses in meerkats. Behav Ecol 2012. [DOI: 10.1093/beheco/ars154] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Siutz C, Millesi E. Effects of birth date and natal dispersal on faecal glucocorticoid concentrations in juvenile Common hamsters. Gen Comp Endocrinol 2012; 178:323-9. [PMID: 22732077 PMCID: PMC3423633 DOI: 10.1016/j.ygcen.2012.06.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Revised: 06/04/2012] [Accepted: 06/08/2012] [Indexed: 11/21/2022]
Abstract
In seasonally breeding animals, timing of reproduction in females can influence offspring development and survival. Temporal and energetic constraints are often more pronounced in juveniles born late in the season, and could activate the stress axis. Common hamsters (Cricetus cricetus) are hibernating rodents, and adult females produce up to three litters during the active season. Birth dates range from May to September, and shortly after natal emergence pups are weaned and start to disperse. In this study, we used faecal cortisol metabolites (FCM) as a non-invasive measure of recent glucocorticoid exposure. We compared FCM levels between early- (June/July) and late- (August/September) born juvenile Common hamsters during their first weeks after natal emergence. We further compared FCM levels in juveniles born in the study area and individuals that immigrated either early or late in the season. Additionally, we investigated potential effects of human disturbances on cortisol secretion patterns. FCM levels in late-born juveniles increased during the first weeks post-emergence and were significantly higher than those in early-born individuals during the post-weaning period. Late-immigrating juveniles had significantly higher FCM levels than early immigrants and residents during the same time period. Individuals that inhabited areas frequently used by humans had higher FCM levels than those in low-impact areas. These results indicate that the seasonal timing of birth and dispersal affect cortisol secretion patterns in juvenile Common hamsters. As all juveniles immerged into their hibernacula during early October, we assume that late-born and late-immigrated individuals have less time to prepare for hibernation. This could elevate energetic demands and increase exposure to predators and/or humans during food caching. These factors might lead to increased adrenal activity and thus, elevated FCM concentrations in these individuals. Potential consequences of these time constraints and associated physiological effects could be reflected in the lower overwinter survival rates of juveniles born late in the season.
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Affiliation(s)
- Carina Siutz
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
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Machatschke IH, Bauer B, Glenk LM, Millesi E, Wallner B. Spatial learning and memory differs between single and cohabitated guinea pigs. Physiol Behav 2010; 102:311-6. [PMID: 21145334 DOI: 10.1016/j.physbeh.2010.12.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 11/15/2010] [Accepted: 12/01/2010] [Indexed: 11/26/2022]
Abstract
In socially-living animals, social enrichment enhances spatial learning and memory while separation from conspecifics can severely impair these abilities. In the present work, guinea pigs were kept in isolation or cohabitated in heterosexual pairs and then subjected to a labyrinth task. Latency-time to bait, error-rate, amount of movement and pre- and post-experimental cortisol (CORT) were registered. During a 5d-acquisition phase, single animals (N=19) showed a more efficient encoding of spatial information, with significantly decreased latency-time and error-rate over the time course. In contrast, cohabitated animals (N=19) did not show a significant improvement. Three days after acquisition, memory was tested in a retention test, under the same conditions. With regard to behavioral performance, there was no significant difference between cohabitated and single animals. Pre-experimental CORT was significantly higher in cohabitated animals when compared to single ones. Post-experimentally, CORT increased significantly in singles but not in cohabitated animals when compared to pre-experimental values. Thus, both groups did not differ from each other at that point. Social condition seemed to be an important modulator, in that learning and memory were more impaired in paired animals than in single ones. The failure of cohabitated animals to encode spatial memory more quickly may have been caused by a more chronically up-regulated HPA-axis. The post-experimental CORT increase of singles may be due to more efficient handling of short-term stress exposure.
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Wallner B, Aspernig D, Millesi E, Machatschke IH. Non-lactating versus lactating females: a comparison of sex steroids, sexual coloration, and sexual behavior in Japanese macaques. Primates 2010; 52:69-75. [PMID: 20878441 DOI: 10.1007/s10329-010-0221-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Accepted: 09/02/2010] [Indexed: 11/28/2022]
Abstract
Female Japanese macaques are seasonal breeders distinguished by their red-colored hindquarters, face, and nipple skin areas. Intensity of coloration seems to be associated with sexual attractiveness, behavior, and fluctuating sex steroids. Our aim was to investigate whether the color intensity of these regions differed between lactating (LA) and non-lactating (NLA) females during sexually inactive (SI) and active (SA) phases. Coloration scores of 19 adult females were classified using color tables. Estrogen and progesterone metabolites were determined in fecal samples. Weekly comparison between both groups revealed significantly increased coloration of the hindquarters area from week 13 (SI) until the end of the observation period, and for the nipple skin throughout the SI and SA periods. Face coloration differed marginally. Hormonally, NLA females showed significantly increased excretion rates of sex steroids at the end of the SI phase and throughout the whole SA period. Logistic regression analyses between elevated fecal steroids and nipple coloration disclosed a significant relationship for NLA females during the SI period. This connection persisted and included hindquarter coloration during the SA period. NLA females showed increased intromission with ejaculation, but no difference was found for intromission without ejaculation. In conclusion, results demonstrate increased endocrine excretion rates for NLA females during the whole observation period, paralleled by an enhanced, fertility-signaling sexual attractiveness.
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Affiliation(s)
- Bernard Wallner
- Department of Anthropology, University of Vienna, Althanstr. 14, 1090, Vienna, Austria.
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Goldenberg M, Goldenberg F, Funk SM, Henschel J, Millesi E. Diet composition of black-backed jackals,Canis mesomelasin the Namib Desert. Folia Zoologica 2010. [DOI: 10.25225/fozo.v59.i2.a3.2010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Martina Goldenberg
- Department of Behavioural Biology, University of Vienna, Vienna, Austria;,
- Gobabeb Training and Research Centre (GTRC), Namibia
| | - Florian Goldenberg
- Department of Behavioural Biology, University of Vienna, Vienna, Austria;,
- Gobabeb Training and Research Centre (GTRC), Namibia
| | - Stephan M. Funk
- Nature Heritage, St. John, Jersey, Channel Islands
- present address: Durrell Wildlife Conservation Trust, Jersey, Channel Islands
| | - Joh Henschel
- Gobabeb Training and Research Centre (GTRC), Namibia
| | - Eva Millesi
- Department of Behavioural Biology, University of Vienna, Vienna, Austria;,
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Millesi E, Huber S, Dittami J, Hoffmann I, Daan S. Parameters of Mating Effort and Success in Male European Ground Squirrels, Spermophilus citellus. Ethology 2010. [DOI: 10.1111/j.1439-0310.1998.tb00070.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Strauss A, Hoffmann IE, Walzl M, Millesi E. Vaginal oestrus during the reproductive and non-reproductive period in European ground squirrels. Anim Reprod Sci 2008; 112:362-70. [PMID: 18585876 DOI: 10.1016/j.anireprosci.2008.05.068] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2007] [Revised: 04/26/2008] [Accepted: 05/21/2008] [Indexed: 11/16/2022]
Abstract
Most hibernating animals are thought to be monoestrous because reproductive activity is subject to strong time constraints. In previous studies, female European ground squirrels (Spermophilus citellus) turned out to have elevated oestradiol levels during late lactation and after weaning, indicating ovarian activity during summer. Therefore, we monitored vaginal cytology, endocrine changes, and vulval development in semi-free-living female European ground squirrels throughout one active season. Vaginal oestrus, defined by the predominance of cornified cells in smear samples, was found during the mating period shortly after vernal emergence. This phase was followed by metoestrus, characterised by the appearance of leukocytes, and a subsequent anoestrous phase. During weaning or postlactation, a second vaginal oestrus was documented in all experimental females, again followed by a metoestrous and an anoestrous phase lasting until hibernation. In line with the second vaginal oestrus, plasma oestradiol concentrations peaked during postlactation. Progesterone levels were elevated from gestation to postlactation, and titres were marginally higher during vaginal oestrus in summer than in spring. Vulval swelling was more pronounced during the first than the second vaginal oestrus. The second oestrous cycle was non-reproductive, as males were sexually inactive with regressed testes during summer. We assume that the second oestrous cycle and the accompanying endocrine changes have beneficial effects on prehibernatory fattening and reproductive performance in the subsequent season. This might allow females to become oestrous immediately after emergence from hibernation in spring.
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Affiliation(s)
- Anna Strauss
- Department of Behavioural Biology, University of Vienna, Althanstr. 14, 1090 Vienna, Austria.
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Millesi E, Strauss A, Burger T, Hoffmann IE, Walzl M. Follicular development in European ground squirrels (Spermophilus citellus) in different phases of the annual cycle. Reproduction 2008; 136:205-10. [PMID: 18469039 DOI: 10.1530/rep-08-0090] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In seasonally breeding mammals, in particular hibernators, reproduction underlies severe energetic and temporal constraints to enable the allocation of sufficient body fat reserves before winter. Thus, the timing of conception in spring can be crucial in terms of reproductive success. This study investigates follicular development in European ground squirrels (Spermophilus citellus) in three phases of the annual cycle: at vernal emergence, after weaning the offspring and shortly before hibernation. The animals were kept in outdoor enclosures within the natural habitat of the species. They were captured in weekly intervals, weighed and reproductive status was determined. Unilateral ovariectomy was scheduled such that the three periods were sampled. Numbers and diameters of tertiary follicles (TF) and corpora lutea (CL) in each ovary were determined, and plasma oestradiol and progesterone levels were analysed. The highest numbers of TF, including Graafian follicles, were found in ovaries at vernal emergence. During post-lactation, the number of TF was lower and active CL appeared in the investigated ovaries. Shortly before hibernation, active CL were present, but luteolysis had started in some individuals. Both oestradiol and progesterone secretion peaked after the termination of lactation and decreased before hibernation. The results demonstrate a second oestrus cycle in European ground squirrels after weaning, including an active luteal phase. This non-reproductive oestrus cycle with its endocrine output is an intriguing phenomenon. It may positively affect both prehibernatory fattening and reproduction in the subsequent season.
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Affiliation(s)
- Eva Millesi
- Department of Behavioural Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria.
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Strauss A, Mascher E, Palme R, Millesi E. Sexually mature and immature yearling male European ground squirrels: a comparison of behavioral and physiological parameters. Horm Behav 2007; 52:646-52. [PMID: 17927989 DOI: 10.1016/j.yhbeh.2007.08.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Revised: 08/07/2007] [Accepted: 08/08/2007] [Indexed: 11/23/2022]
Abstract
Early puberty may increase lifetime reproductive success, but may also entail diverse costs. In male European ground squirrels (Spermophilus citellus), age at sexual maturity varies among individuals. We compared sexually active and inactive yearling males under standardized conditions in outdoor enclosures. Non-reproductive yearling males hibernated significantly longer than mature males and emerged when the mating period had already started. Testosterone concentrations peaked in the precocious males during premating and mating, and were depressed in the non-reproductive individuals throughout the study period. Emergence body mass was similar in both groups, although sexually immature males were significantly heavier at the end of the active season. Additionally, non-reproductive yearlings grew faster than precocious individuals. Male-male aggression peaked during mating and the following 4 weeks. Intense aggressive interactions like chases and fights were mostly initiated by reproductive males and were directed towards mature competitors. Aggressive behavior in immature males was mainly expressed as spatial displacements. Non-agonistic interactions with females were only observed in sexually active males. Concentrations of fecal cortisol metabolites did not differ between the two male groups and were elevated in the second half of the active season. Leucocyte numbers were reduced during mating in mature males, whereas in immature animals, cell numbers did not change significantly. Our results indicate that early puberty in European ground squirrels involves lower growth rates, high intrasexual aggression, lower prehibernatory body mass, and probably worse immunological condition during mating.
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Affiliation(s)
- Anna Strauss
- Department of Behavioural Biology, University of Vienna, Althanstr 14, A-1090 Vienna, Austria.
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Franceschini C, Siutz C, Palme R, Millesi E. Seasonal changes in cortisol and progesterone secretion in Common hamsters. Gen Comp Endocrinol 2007; 152:14-21. [PMID: 17408667 DOI: 10.1016/j.ygcen.2007.02.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2006] [Revised: 02/05/2007] [Accepted: 02/07/2007] [Indexed: 11/16/2022]
Abstract
In this study, we investigated endocrine factors and behaviour in free-living Common hamsters (Cricetus cricetus) during reproductive and non-reproductive periods of the annual cycle. We applied a non-invasive method to gain information on seasonal changes in adrenocortical activity in male and female hamsters by analysing faecal glucocorticoid metabolite concentrations (FCM). In addition, plasma progesterone concentrations were monitored in females throughout the non-hibernation season. The animals were live-trapped from spring emergence until the onset of hibernation in autumn. Reproductive status was determined at capture and blood and faecal samples were collected. During behavioural observations, agonistic and sexual interactions were recorded. FCM concentrations were significantly higher in males than in females during the reproductive period. In males, a pronounced increase in FCM during the reproductive period coincided with high frequencies of intrasexual aggression. In females, FCM levels remained relatively constant. Aggressive behaviour in females increased during the reproductive period, but was much less frequent than in males. Females, which successfully raised a second litter after a postpartum oestrus and concurrent lactation and gestation had lower FCM levels than individuals, which lost their second litter after parturition. As expected, plasma progesterone concentrations were low before and after the reproductive period. During gestation, levels peaked and remained elevated during lactation. The results of this field study provide insight in critical periods associated with reproduction in male and female Common hamsters.
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Affiliation(s)
- Claudia Franceschini
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria.
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Aschauer A, Hoffmann IE, Millesi E. Endocrine profiles and reproductive output in European ground squirrels after unilateral ovariectomy. Anim Reprod Sci 2005; 92:392-400. [PMID: 16046255 DOI: 10.1016/j.anireprosci.2005.06.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2004] [Revised: 05/02/2005] [Accepted: 06/10/2005] [Indexed: 10/25/2022]
Abstract
In the course of a long-term study on reproductive physiology and behaviour in female European ground squirrels (Spermophilus citellus) we investigated interactions among reproductive timing, maternal effort and hibernation. To gain information on the state of follicular development shortly before hibernation, histological investigations of ovaries were carried out. To collect the ovaries, unilateral ovariectomy was chosen as the least invasive method. The aim of this study was to monitor patterns of hormone secretion, behavioural parameters and reproductive output in females after unilateral ovariectomy, and compare them with intact individuals to assess potential effects of the treatment. Reproductive performance including duration of gestation and lactation, litter size, and offspring mass at natal emergence were similar in treated and untreated individuals. Before weaning, plasma estradiol levels were higher in the hemicastrated group than in intact females. Progesterone concentrations tended to be lower in unilaterally ovariectomized females during gestation and postlactation. In both groups we measured cortisol metabolites in fecal samples to estimate basal adrenal activity. Untreated individuals had significantly higher cortisol levels than hemicastrated females during lactation. In all other phases no significant differences in patterns of cortisol excretion were found between the two groups. Prehibernatory body-mass did not differ between treated and untreated females. These results indicate that unilateral ovariectomy had no significant negative effects on reproductive timing and output in female European ground squirrels. Compensatory activity of the remaining ovary does occur, concerning estradiol secretion even a kind of overcompensation was reported. These elevated estradiol levels in unilaterally ovariectomized females could play a role in limiting the degree of follicular compensation.
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Affiliation(s)
- Anna Aschauer
- Department of Neurobiology and Behavioural Sciences, University of Vienna, Althanstr. 14, 1090 Vienna, Austria.
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Everts LG, Strijkstra AM, Hut RA, Hoffmann IE, Millesi E. Seasonal variation in daily activity patterns of free-ranging European ground squirrels (Spermophilus citellus). Chronobiol Int 2004; 21:57-71. [PMID: 15129824 DOI: 10.1081/cbi-120027982] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Daily aboveground activity of European ground squirrels (Spermophilus citellus) in their natural habitat was recorded with a visual scanning procedure during the active seasons of 1992 and 1993. Activity patterns were analyzed with respect to time of year and to the animal's reproductive state. Aboveground activity started on average 3.9 h (SD 0.6 h, n = 37 days) after civil twilight at dawn and ended on average 3.2 h (SD 0.9 h, n = 37 days) before civil twilight at dusk. Between onset and offset of activity, 54% was spent aboveground, of which 73% was spent foraging. Activity patterns were influenced by photoperiod, rainfall, and by reproductive state. During mating, reproductively active males started activity earlier than females and reproductively inactive males. For females, time spent foraging was high during lactation. The midpoint of daily activity was at 12:16 h (SD 0.37 h, n = 37 days). Activity patterns of European ground squirrels thus appear robustly positioned in the middle of the photoperiod.
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Affiliation(s)
- Lammina G Everts
- Animal Behaviour, University of Groningen, Haren, The Netherlands
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Millesi E, Hoffmann IE, Steurer S, Metwaly M, Dittami JP. Vernal changes in the behavioral and endocrine responses to GnRH application in male European ground squirrels. Horm Behav 2002; 41:51-8. [PMID: 11863383 DOI: 10.1006/hbeh.2001.1735] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This field study was aimed at examining hypothalamic involvement in the behavioral changes of male European ground squirrels (Spermophilus citellus) before, during, and after the mating season. The effects of exogenous gonadotropin-releasing hormone (GnRH) application on androgen secretion and behavioral patterns were investigated. Animals were captured, bled, and injected intramuscularly with 40 ng/100 g of GnRH. A second plasma sample was collected 40 min after the treatment to document changes in testosterone secretion. Behavioral parameters such as intra-sexual aggression, scent marking, and home range size were compared on the days before and after the stimulation. In the first two phases, before female emergence and during mating, GnRH-injection caused increases in plasma testosterone. In the post-mating phase, initial plasma testosterone levels had decreased and no elevation could be induced. Sham treatment of controls had no effect in any phase. Conditional parameters like emergence body mass and testicular size covaried with androgen increases only in the pre-mating period. Behavioral changes after GnRH administration occurred during the pre-mating period. Intra-sexual aggression, scent marking, and home range size increased significantly in experimental individuals. Later, during mating and post-mating, we found no behavioral changes associated with the GnRH treatment or the testosterone increase. The results demonstrate changes in the endocrine and behavioral sensitivity to GnRH application, according to the phases of the active season. An exogenous pulse of GnRH can apparently release behavior in male European ground squirrels, which is normally context dependent with the emergence of females.
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Affiliation(s)
- Eva Millesi
- Institute of Zoology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria.
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Abstract
Effects of hibernation on memory were tested in European ground squirrels (Spermophilus citellus). The animals were trained in summer to successfully accomplish two tasks: a spatial memory task in a maze and an operant task on a feeding machine. One group hibernated normally, and the other was prevented from hibernation by maintaining ambient temperature at 22 degrees C. In spring, the same tasks were repeated for both groups and their individual performances compared to the initial training phase. The experimental groups differed significantly in both tasks. The nonhibernating animals had higher levels of retention and needed significantly fewer trials to relearn the tasks than the group that had hibernated. In addition to testing the retention of conditioned tasks, social memory was also studied. The ground squirrels were given a social recognition test in spring with one familiar and one unfamiliar conspecific. In contrast to the conditioned tasks, social memory did not seem to be affected by hibernation. The results indicate negative effects of hibernation on the retention of conditioned tasks, which could produce important constraints on animals. A potential explanation for this memory loss might be changes in neuronal activity, which occur during hibernation.
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Affiliation(s)
- E Millesi
- Institute of Zoology, University of Vienna, Austria
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Abstract
The course of behavioral and vaginal estrus and patterns of circulating estrogens were followed in free-living European ground squirrels (Spermophilus citellus) after their emergence from hibernation. Normally mating females were compared to a second group in an area where males had been removed from the population before female emergence. Both groups showed vaginal estrus, but the patterns differed. Mating shortened vaginal estrus to a 3-day period compared to 8 days in unmated females. The extent (cell number) of cell cornification during estrus and the cellular components (percentage distribution) of metestrus did not differ between the two groups. Females in the area without males had significantly higher estrogen levels during estrus and metestrus compared to those in the control area. European ground squirrels were found to be monestrous, as none of the unmated females reentered estrus after metor diestrus was detected. The prolongation of vaginal estrus in unmated females can be viewed as either a physiological inevitability or an adaptation to low mate availability. The extension is still relatively short compared to other sciurid species and perhaps a product of constraints producing a strict time frame for reproduction.
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Affiliation(s)
- E Millesi
- Institute of Zoology, University of Vienna, Austria.
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Millesi E, Strijkstra AM, Hoffmann IE, Dittami JP, Daan S. Sex and Age Differences in Mass, Morphology, and Annual Cycle in European Ground Squirrels, Spermophilus citellus. J Mammal 1999. [DOI: 10.2307/1383222] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Millesi E, Huber S, Everts LG, Dittami JP. Reproductive Decisions in Female European Ground Squirrels: Factors Affecting Reproductive Output and Maternal Investment. Ethology 1999. [DOI: 10.1046/j.1439-0310.1999.00379.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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