Meeting Abstract
It is widely accepted that estrogens affect the development of chronic pain, but the mechanism is not well understood. Pain studies involving mammals are complicated by estrogen’s role in cyclical fertility, and there is little research on animal models that lack estrogen cycles. The cephalopod Euprymna scolopes is a promising model for such studies. Its nervous system is large and complex, and cephalopods express estrogen receptors in brain areas involved in cognition, long-term memory and sensory processing. E. scolopes demonstrates both short- and long-term sensitization after injury, and as a coastal marine organism, is vulnerable to increasing levels of estrogenic pollutants in surface waters. To determine the effects of estrogen exposure coupled with injury on the nervous system of the squid, I will expose groups to either no, chronic, or acute doses of ethinyl estradiol (EE2) in tank water and compare neuroanatomy, behavior and neural excitability among the treatments. Half the squid in each group will receive a tissue injury at 14 days post hatching. The chronically exposed squid will be reared in water containing a low dose of EE2 throughout life, replicating the effect of chronic environmental exposures. The acutely exposed group will receive a single higher pulse of EE2 added to water prior to injury, mimicking the interaction of an estrogen peak co-incident with inflammation. I hypothesize that estrogen exposure heightens behavioral and neural sensitization after injury. However, preliminary data suggests that estrogen-exposed squid show reduced responses to injury. This work will increase our understanding of conserved mechanisms of estrogen/injury interactions and will improve knowledge of eco-systems effects of environmental estrogens.
