Species differences in neuropeptides and social behavior

I conducted field work in South America in order to compare the oxytocin receptor systems of social and nonsocial with the genus Ctenomys -- a species-rich group of burrowing rodents known as tuco-tucos. My initial work focused on a solitary and a social species that share similar habitats in the Limay river valley of Argentina. I am currently studying a broader range of tuco-tucos from Argentina, Uruguay, and Peru.

Beery AK, Lacey EA, Francis DD (2008) Oxytocin and vasopressin receptor distributions in a solitary and a social species of tuco-tuco (Ctenomys sociabilis and Ctenomys haigi). Journal of Comparative Neurology. 507: 1847-1859.

Non-sexual affiliative behavior in group-living voles

In my graduate work I used meadow voles as a model of environmentally regulated social bonding. Female meadow voles are territorial during the summer reproductive season, but huddle in groups in the winter. Day length variation in the laboratory induces a behavioral shift in huddling behavior, and this allowed me to explore the proximate mechanisms that affect social bonding between same-sex individuals including the roles of estradiol, oxytocin, and their receptors.

Beery AK, Routman DM, Zucker I. (2009). Same-sex social behavior in meadow voles: multiple and rapid formation of attachments.  Physiology & Behavior. 97: 52-57

Beery AK, Loo TJ, Zucker I (2008). Day length and estradiol affect same-sex affiliative behavior in the female meadow vole. Hormones & Behavior.  54:153-159

(2 additional articles in prep)

Gene-environment interactions and brain development

I am currently studying how early life experience and environment affect long-term regulation of gene expression and behavior by epigenetic and other mechanisms.  Exposure of rat pups to high or low levels of maternal care-giving in the first few days of life can alter the regulation of stress-reactivity into adulthood.  These changes in behavior accompany changes in glucocorticoid receptor gene expression and DNA methylation among others.  I am using this model to explore several aspects of phenotypic plasticity in response to external circumstances.

Seasonal changes in fertility and mating behavior

Syrian hamsters are a model of a photoperiodic, seasonally breeding species that has a robust 4 day estrous cycle. In my first few experiments I investigated the relative contribution of male and female fertility decline to the termination of offspring production in short day lengths, and effects of breeding in short day lengths on offspring characteristics.

Beery AK, Paul MJ, Routman DM, Zucker I (2008) Maternal photoperiodic history affects offsprig development in Syrian hamsters.  Journal of Biological Rhythms  23(5):445-455.

Beery AK, Trumbull JJ, Tsao JM, Costantini RM, Zucker I. (2007) Sex differences in the onset of seasonal reproductive quiescence. Proceedings of the Royal Society: Biology 274:281-286

Costantini RM, Park JH, Beery AK, Paul MJ, Ko JJ, Zucker I. (2007) Post-castration retention of reproductive behavior and olfactory preferences in male Siberian hamsters: role of prior experience. Hormones and Behavior 51(1):49-55.

Park JH, Kauffman AS, Paul MJ, Butler MP, Beery AK, Costantini RM, Zucker I. (2006) Interval timer control of puberty in photoinhibited Siberian hamsters. Journal of Biological Rhythms 21(5):373-383.