Naked mole-rats are eusocial rodents that live in subterranean colonies with a strict reproductive and social hierarchy. Breeders are socially dominant and other colony members are non-reproductive subordinates. The effects of manipulating the serotonergic system on aggression are well studied in many species, but not in eusocial rodents like the naked mole-rat. For the current study, the effects of fluoxetine hydrochloride (FLX) on status-specific behaviours of subordinates (Experiment 1) and queens (Experiment 2) were evaluated both in-colony and in a social-pairing paradigm to investigate how the serotonergic system influences aggression in this species. In accordance with our main hypothesis, chronic treatment of FLX attenuated the frequency and duration of aggression in queens, but not subordinates, when paired with an unfamiliar conspecific. Further exploration of pharmacological manipulation on status-specific behaviours of this eusocial species may elucidate the neurobiological mechanisms underlying their unique and rigid social hierarchy.

Naked mole-rats are eusocial rodents that live in subterranean colonies with a strict reproductive and social hierarchy. Breeders are socially dominant and other colony members are non-reproductive subordinates. The effects of manipulating the serotonergic system on aggression are well studied in many species, but not in eusocial rodents like the naked mole-rat. For the current study, the effects of fluoxetine hydrochloride (FLX) on status-specific behaviours of subordinates (Experiment 1) and queens (Experiment 2) were evaluated both in-colony and in a social-pairing paradigm to investigate how the serotonergic system influences aggression in this species. In accordance with our main hypothesis, chronic treatment of FLX attenuated the frequency and duration of aggression in queens, but not subordinates, when paired with an unfamiliar conspecific. Further exploration of pharmacological manipulation on status-specific behaviours of this eusocial species may elucidate the neurobiological mechanisms underlying their unique and rigid social hierarchy.

Mole-rats are placental mammals which are perfectly adapted to subterranean life. In this thesis I present novel findings on working metabolism and thermoregulatory physiology of mole-rats. These animals cope with low availability of food and have thus employed multiple strategies how to conserve energy and/or use it more effectively. Among other adaptations this resulted in lower resting body temperature, tolerance to increase in body temperature during exercise or while at rest, surprisingly efficient cooling while digging and precise diurnal and seasonal timing of activity with regards to environmental conditions. My focus in this work is on the digging metabolic rate and thermoregulation of social Fukomys mechowii and solitary Heliophobius argenteocinereus in soft and hard substrate, thermoregulatory abilities of Fukomys darlingi, seasonal changes of activity in free living Heliophobius argenteocinereus measured as daily energy expenditure and, finally, energetic consequences of the daily activity patterns of Fukomys anselli.

Background: The naked mole-rat (NMR) is a long-lived and cancer resistant species. Identification of potential anti-cancer and age related mechanisms is of great interest and makes this species eminent to investigate anti-cancer strategies and understand aging mechanisms. Since it is known that the NMR expresses higher liver mRNA-levels of alpha 2-macroglobulin than mice, nothing is known about its structure, functionality or expression level in the NMR compared to the human A2M. Results: Here we show a comprehensive analysis of NMR- and human plasma-A2M, showing a different prediction in glycosylation of NMR-A2M, which results in a higher molecular weight compared to human A2M. Additionally, we found a higher concentration of A2M (8.3±0.44 mg/mL vs. and 4.4±0.20 mg/mL) and a lower total plasma protein content (38.7±1.79 mg/mL vs. 61.7±3.20 mg/mL) in NMR compared to human. NMR-A2M can be transformed by methylamine and trypsin resulting in a conformational change similar to human A2M. NMRA2M is detectable by a polyclonal antibody against human A2M. Determination of tryptic and anti-tryptic activity of NMR and human plasma revealed a higher anti-tryptic activity of the NMR plasma. On the other hand, less proteolytic activity was found in NMR plasma compared to human plasma.

Background: A variety of microbial communities exist throughout the human and animal body. Genetics, environmental factors and long-term dietary habit contribute to shaping the composition of the gut microbiota. For this reason the study of the gut microbiota of a mammal exhibiting an extraordinary life span is of great importance. The naked mole-rat (Heterocephalus glaber) is a eusocial mammal known for its longevity and cancer resistance. Methods: Here we analyzed its gut microbiota by cultivating the bacteria under aerobic and anaerobic conditions and identifying their species by mass spectrometry. Results: Altogether, 29 species of microbes were identified, predominantly belonging to Firmicutes, and Bacteroidetes. The most frequent species were Bacillus megaterium (45.2 %), followed by Bacteroides thetaiotaomicron (19.4 %), Bacteroides ovatus, Staphylococcus sciuri and Paenibacillus spp., each with a frequency of 16.1 %. Conclusion: Overall, the gut of the naked mole-rat is colonized by diverse, but low numbers of cultivable microbes compared with humans and mice. The primary food plants of the rodents are rich in polyphenols and related compounds, possessing anti-microbial, anti-inflammatory, anti-oxidative as well as anti-cancer activity which may contribute to their exceptionally healthy life.