Biology subjects

Sergott, C. E.

Publications and source records attributed to Sergott, C. E..

3 recordsLinked to original sources

bioRxiv2025

Differences in Auditory Brainstem Responses between Laboratory-reared and Wild-caught Prairie Voles (Microtus ochrogaster)

Prairie voles (Microtus ochrogaster) are a semi-fossorial rodent that are an emerging model in social neuroscience. Comparing laboratory-reared and wild-caught individuals is essential for understanding how environmental history shapes neural and sensory traits and for assessing the ecological validity of laboratory findings. Despite this, relatively few studies have taken this approach. We used auditory brainstem responses (ABRs) to compare ABR thresholds and ABR wave characteristics between laboratory-reared and wild-caught prairie voles. ABR recordings show that, similar to other semi-fossorial rodents, M. ochrogaster exhibit a hearing range of 1 - 46 kHz with peak sensitivity around 8 to 32 kHz. However, wild-caught prairie voles displayed significantly lower ABR thresholds at 1, 4, 8, 16, and 24 kHz compared to laboratory-reared prairie voles. There were significant differences in interpeak latency between both tested groups, with laboratory-reared prairie voles showing faster interpeak latency responses than wild-caught voles. However, there were no differences in amplitude ratios between groups. Laboratory-reared prairie voles showed faster normalized latencies and higher relative amplitude of the binaural interaction component (BIC) of the ABR than wild-caught voles. There were no significant differences in ABR thresholds, interpeak latency, amplitude ratio, normalized latency, and relative amplitude between the sexes. These differences in auditory processing support the importance of integrating both wild and captive populations to advance comparative auditory research. SUMMARY STATEMENTWild and laboratory-reared prairie voles show distinct auditory processing, highlighting how environment history shapes hearing and underscoring the need for comparative studies.

neuroscience↗

bioRxiv2024

Exposure to novel females increases fecundity in adult male prairie voles

Social circuitry of the mammalian brain can influence male reproductive physiology. This often manifests as plasticity in sperm production or allocation, particularly in response to male-male competition. However, socially mediated testicular plasticity has not been investigated with respect to mating and parental strategy. Testis mass and sperm production of sexually naive and female-exposed adult male individuals of three rodent species were compared: the socially monogamous and paternal prairie vole (Microtus ochrogaster), the promiscuous and non-paternal meadow vole (Microtus pennsylvanicus), and the promiscuous and non-paternal house mouse (Mus musculus). Monogamously paired prairie vole males exhibited significantly larger testes and greater sperm production than naive prairie vole males. Comparatively, there were no significant differences between naive and monogamously paired male meadow voles or mice. To investigate the role of olfactory cues for regulating this phenomenon in prairie voles, a group of naive males exposed to soiled bedding from novel females was used. These males were more similar to paired males than to naive males not exposed to novel female odors, demonstrating a strong role of the social olfactory system. Further, while the predictions of sperm competition theory (species with greater female promiscuity have larger testes than closely related species with less female promiscuity) are consistent between naive meadow voles and prairie voles, the prediction does not hold for monogamously paired prairie voles and meadow voles. This demonstrates the complexity of internal social dynamics and reproductive pressures which socially monogamous paternal males face and the evolutionary adaptions that may develop in response.

physiology↗

bioRxiv2024

VARIATION IN HEAD AND PINNA MORPHOLOGY OF PRESERVED PEROMYSCUS SPP. SPECIMENS AND IMPLICATIONS FOR AUDITORY FUNCTION

The characteristics of an animals head and pinna mark the beginning of auditory communication. Auditory communication is broadly achieved by receiving sounds from the environment and plays a vital role in an animals ability to perceive and localize sounds. Natural history museums and collections along with their vast repositories of specimens provide a unique resource for examining how the variability in both the size and shape of the head and pinna cause variability in the detection of acoustic signals across species. Using this approach, we measured the dimensions of the head and pinna of over 1,200 preserved specimens of Peromyscus boylii, P. californicus, P. gossypinus, P. leucopus, P. maniculatus, and P. truei, followed by a series of head-related transfer functions (HRTFs) on several individuals to study the relationship between morphology and available auditory information. Our morphological results show significant variation in pinna length and width, as well as in the distance between the two ears across the six species. ITDs and ILDs were calculated and demonstrated consistent results across species, suggesting the differences in head and pinna size do not significantly modify these cues. Not only does this study contribute to existing research on external morphology and auditory function, but it also provides valuable insight into the use of preserved specimens in auditory research, an area that is currently understudied. Summary statementThis work aims to provide insight into using natural history museum specimens for morphological research pertaining to the auditory system in small mammals.

evolutionary biology↗