Biology subjects

Tripp, J. A.

Publications and source records attributed to Tripp, J. A..

7 recordsLinked to original sources

bioRxiv2026

Ghrelin inhibits courtship ultrasonic vocalization in male mice

Courtship is an essential component of reproductive success for many species and many courtship behaviors, such as vocalization, are energetically demanding. In order to successfully balance investment in courtship with feeding and foraging, individuals must be aware of their current energy balance, and hormonal signals of energetic state have been found to influence social signal effort across a variety of species. Ghrelin is one hormone that plays an important role in regulating energy balance by signaling hunger and promoting feeding. Previous studies have investigated the role of ghrelin in courtship, aggression, and mating behavior. In this study, we build on prior work by investigating the effects of ghrelin on ultrasonic vocalizations (USV) and other courtship behaviors of male mice. We expand on previous research by observing ghrelin's effects over longer interactions, allowing us to understand how ghrelin impacts the dynamics of USV production over time. Our results show that while males initially vocally court females at a high rate regardless of treatment, ghrelin reduces overall USV production by increasing the rate of decline of vocalization. Surprisingly, despite its effects on vocal courtship, we found no significant differences in the production or timing of other, non-vocal, courtship behaviors. This study deepens our understanding of the role of hormones traditionally associated with controlling hunger and feeding in regulating social behaviors.

animal behavior and cognition↗

bioRxiv2025

Leptin promotes social context-specific increase in advertisement song effort of male Alston's singing mice

Animal display behaviors, such as advertisement songs, are flashy and attention grabbing by necessity. In order to balance the costs and benefits of such signals, individuals must be able to assess both their own energetic state and their social environment. In this study, we investigated the role of leptin, a hormonal signal of high energy balance, in regulating the vocal advertisement display of Alstons singing mouse (Scotinomys teguina). We manipulated perception of energy balance using exogenous leptin, and social environment through acoustic playback, to ask how internal cues of energy availability are integrated with external social cues that promote singing. We found that both song playback and leptin injection promoted increased song effort. In the absence of song playback, leptin altered amplitude modulation in songs, but did not affect song rate. Additionally, we examined hormone and playback effects on non-vocal behaviors and found that leptin may shift physical activity away from cage exploration and toward wheel running. Finally, we found several positive associations between measures related to high song effort. These results demonstrate that male singing mice use both social context and energy balance to govern their investment in advertisement song and that leptin acts as a mediator of this process.

animal behavior and cognition↗

bioRxiv2024

Female song elicits increased vocal display effort in both sexes of Alston's singing mouse

Acoustic displays are conspicuous behaviors common across diverse animal taxa. They have long been studied in behavioral ecology, evolutionary biology, and neuroscience. Most of these investigations, however, have focused on male display. For species in which both sexes display, correcting this bias will lead to a fuller understanding of the evolution and function of these behaviors. In this study, we investigated the role of vocal advertisement display in female Alstons singing mice (Scotinomys teguina). Singing mice are small muroid rodents of the family Cricetidae, native to high altitude cloud forests of Central America. Females and males both produce elaborate advertisement songs used in mate attraction and intra-sexual competition. Prior studies have largely focused on male behavior, though we recently found that both sexes dramatically increase their rate of singing and song duration in response to playback of conspecific male song. Here, we tested how mice of both sexes adjust their song effort in response to female song playback. Our results show that, like male song, female song elicits robust increases in song effort from both female and male mice. This study reveals additional social contexts that promote high song effort in this species, while raising additional questions about the role of song in communication within and between the sexes.

animal behavior and cognition↗

bioRxiv2022

Nitrogen palaeo-isoscapes: Changing spatial gradients of faunal δ15N in late Pleistocene and early Holocene Europe

Nitrogen isotope ({delta}15N) analysis of animal tissue is widely used in archaeology and palaeoecology to investigate diet and ecological niche. Data interpretations require an understanding of nitrogen isotope compositions at the base of the food web (baseline {delta}15N). Significant variation in animal {delta}15N has been recognised at various spatiotemporal scales and linked to changes both in baseline {delta}15N and animal ecology. Isoscapes (models of isotope spatial variation) have proved a useful tool for investigating spatial variability in biogeochemical cycles in present-day marine and terrestrial ecosystems, but so far, their application to palaeo-data has been limited. Here, we present time-sliced nitrogen isoscapes for late Pleistocene and early Holocene Europe (c. 50,000 to 10,000 years BP) using herbivore collagen {delta}15N data. This period covers the Last Glacial-Interglacial Transition, during which significant variation in the terrestrial nitrogen cycle occurred. Our results show clear changes in spatial gradients of {delta}15N through time. Prediction of the lowest faunal {delta}15N values in northern latitudes after, rather than during, the Last Glacial Maximum is consistent with the Late Glacial Nitrogen Excursion (LGNE). We consider the potential of incorporating climatic covariate data into isoscape models but find their inclusion does not improve model performance. These findings have implications for investigating the drivers of the LGNE, which has been linked to increased landscape moisture and permafrost thaw, and for understanding changing isotopic baselines, which are fundamental for studies investigating diets, niche partitioning, and migration of higher trophic level animals.

biochemistry↗

bioRxiv2020

Comparative neurotranscriptomics reveal widespread species differences associated with bonding

BackgroundPair bonding with a reproductive partner is rare among mammals but is an important feature of human social behavior. Decades of research on monogamous prairie voles (Microtus ochrogaster), along with comparative studies using the related non-bonding meadow vole (M. pennsylvanicus), have revealed many of the neural and molecular mechanisms necessary for pair-bond formation in that species. However, these studies have largely focused on just a few neuromodulatory systems. To test the hypothesis that neural gene expression differences underlie differential capacities to bond, we performed RNA-sequencing on tissue from three brain regions important for bonding and other social behaviors across bond-forming prairie voles and non-bonding meadow voles. We examined gene expression in the amygdala, hypothalamus, and combined ventral pallidum/nucleus accumbens in virgins and at three time points after mating to understand species differences in gene expression at baseline, in response to mating, and during bond formation. ResultsWe first identified species and brain region as the factors most strongly associated with gene expression in our samples. Next, we found gene categories related to cell structure, translation and metabolism that differed in expression across species in virgins, as well as categories associated with cell structure, synaptic and neuroendocrine signaling, and transcription and translation that varied among the focal regions in our study. Additionally, we identified genes that were differentially expressed across species after mating in each of our regions of interest. These include genes involved in regulating transcription, neuron structure, and synaptic plasticity. Finally, we identified modules of co-regulated genes that were strongly correlated with brain region in both species, and modules that were correlated with post-mating time points in prairie voles but not meadow voles. ConclusionsThese results reinforce the importance of pre-mating differences that confer the ability to form pair bonds in prairie voles but not promiscuous species such as meadow voles. Gene ontology analysis supports the hypothesis that pair-bond formation involves transcriptional regulation, and changes in neuronal structure. Together, our results expand knowledge of the genes involved in the pair bonding process and open new avenues of research in the molecular mechanisms of bond formation.

neuroscience↗

bioRxiv2020

To hum or not to hum: Neural transcriptome signature of courtship vocalization in a teleost fish

For many animal species, vocal communication is a critical social behavior, often a necessary component of reproductive success. In addition to the role of vocal behavior in social interactions, vocalizations are often demanding motor acts. Through understanding the genes involved in regulating and permitting vertebrate vocalization, we can better understand the mechanisms regulating vocal and, more broadly, motor behaviors. Here, we use RNA-sequencing to investigate neural gene expression underlying the performance of an extreme vocal behavior, the courtship hum of the plainfin midshipman fish (Porichthys notatus). Single hums can last up to two hours and may be repeated throughout an evening of courtship activity. We asked whether vocal behavioral states are associated with specific gene expression signatures in key brain regions that regulate vocalization by comparing transcript levels in humming versus non-humming males. We find that the circadian-related genes period3 and Clock are significantly upregulated in the vocal motor nucleus and preoptic area-anterior hypothalamus, respectively, in humming compared to non-humming males, indicating that internal circadian clocks may differ between these divergent behavioral states. In addition, we identify suites of differentially expressed genes related to synaptic transmission, ion channels and transport, hormone signaling, and metabolism and antioxidant activity that may permit or support humming behavior. These results underscore the importance of the known circadian control of midshipman humming and provide testable candidate genes for future studies of the neuroendocrine and motor control of energetically demanding courtship behaviors in midshipman fish and other vertebrate groups.

neuroscience↗

bioRxiv2019

Preoptic galanin neuron activation is specific to courtship reproductive tactic in fish with two male morphs

Species exhibiting alternative reproductive tactics (ARTs) provide ideal models for investigating neural mechanisms underlying robust and consistent differences in social behavioral phenotypes between individuals within a single sex. Using phospho-S6 protein (pS6), a neural activity marker, we investigate the activation of galanin-expressing neurons in the preoptic area-anterior hypothalamus (POA-AH) during ARTs in midshipman fish (Porichthys notatus) that have two adult male morphs: type I's that reproduce using an acoustic-dependent courtship tactic or a cuckolding tactic, and type II's that only cuckold. The proportion of pS6-labelled galanin neurons increases during mating by courting type I males, but not cuckolders of either male morph or females, and is not explained by vocalization, eggs in the nest, or cuckolders present during mating. These differences within the same behavioral context indicate a male phenotype-specific role for galanin neurons in mating interactions, providing the most direct evidence to date for the role of a specific neuronal population in the differential activation of one mating behavior over the other in species exhibiting ARTs. More broadly, together with their known role in mammalian mating, the results suggest a deep-rooted, phylogenetically shared function for POA-AH galanin neurons in reproductive behavior. As such, these findings also provide new insights into the evolutionary relationship between POA-AH populations involved in social behavior regulation in teleosts, the most species-rich vertebrate group, with those in the more highly differentiated POA-AH of mammals.

neuroscience↗