Current Research and Scholarly Interests
The O'Connell lab studies how genetic and environmental factors contribute to biological diversity and adaptation. We are particularly interested in understanding (1) how behavior evolves through changes in brain function and (2) how animal physiology evolves through repurposing existing cellular components.
Behavior
(1) How do neonates communicate nutritional need to parents? How do parents interpret the cries of their infants? Communication between parents and offspring is required for survival in altricial animals, like mammals (including humans), birds, and some amphibians. Yet we understand very little about the co-evolution of parent-offspring communication from a mechanistic perspective. We are studying the neural basis of parent-offspring communication in poison frogs species where tadpoles beg mothers for meals.
(2) How do poison frogs navigate their environment ? Poison frogs transport their tadpoles from the leaf litter to pools of water. In some species, mothers place tadpoles individually in small plants and then return to feed each tadpole every few days for several months. These behaviors are energetically expensive and cognitively demanding, as not only do frog parents need to remember where these pools are located, but some moms frequently return to feed their tadpoles. We are investigating the neural basis of species differences in spatial cognition as a function of sex differences in parental behavior.
(3) Does the convergent evolution of pair bonding across vertebrates rely on similar neural mechanisms? Social bonds, such as pair bonds, are critical for mental health. In order to identify generalizable and thus translatable principals, we are studying the underlying mechanisms of pair bonding across phylogenically diverse taxa, including butterflyfish, poison frogs, skinks, quail, and voles. This project re-traces the deep, ~450 million years of evolutionary history of vertebrate pair bonding and aims to identify fundamental neural principles that might inform the human condition.
Physiology
(1) How does variation in diet and habitat influence poison frog toxicity? Some poison frog species carry toxic chemicals to avoid predation. Poison frogs do not make their own toxins, but rather sequester toxins from the ants and mites in their diet. Thus, the frogs' ability to defend themselves is tightly linked to their environment. We are studying the trophic ecology of poison frog toxicity by linking together information about habitat, diet, and toxins across many populations and species.
(2) How do frogs sequester toxic small molecules from their diet to serve as chemical defenses? Poison frogs have developed special physiological mechanisms that allow them to uptake and store lipophilic alkaloids from their diet. To accomplish this, they need proteins for alkaloid transport throughout the body and modifications to ion channels that allow toxin resistance. We are studying the evolution of toxin sequestration from an organismal physiology perspective to characterize the toxin uptake system in poison frogs.
