Research Statement

My research interests examine environmental effects on multiple levels of complexity (i.e., behavior, physiology, neuronal communication). For a comparative aspect, I use two species of crayfish which rely on different primary sensory modalities due to evolutionary history.  The general characteristics of anatomical and morphological adaptations in the surface (Procambarus clarkii) and cave (Orconectes australis packardi) crayfish allows for studies of behavioral and physiological compensation mechanisms in response to environmental factors. The significance of my research is to identify factors which impact individuals/populations/species of organisms residing in these two different environments.

Research Foundation

Most animals constantly monitor their environment and alter their behavior based upon sensory information according to various stimuli. These animals possess the complex ability to integrate sensory information and in turn relay the information into motor output to target tissues. It is through these motor outputs that we can gain an understanding of an organism’s response to stimuli.

The fear, flight or fight response has been widely studied in vertebrates and serves as the fundamental physiological basis for examining an organisms awareness to it's' environment under an impending predator attack (Carpenter 1976; Nicholls et al. 2001). It is well known that the autonomic control of the respiratory and cardiovascular systems can regulate oxygen availability and nutrients to specific target tissues needed for an impending behavioral response. By monitoring the internal environment, heart rate (HR) and ventilation rate (VR), researchers can gain a more complete picture of an animal's response (Schapker et al. 2002). This change in internal status may not reflect an external behavioral change which would indicate to others to its own internal readiness. Due to the lack of external changes, it is often difficult for behaviorists to understand the organism’s response to environmental changes. Thus, my current research couples behavioral observations with monitored physiological processes for a more complete understanding of an animal’s autonomic state, especially during a time in which behavioral observations would not give a full and complete assessment in response to various stimuli.

Current Research Interests:

1. Comparative studies of behavioral and physiological influences during social interactions in crayfish
2. Comparative studies on physiological and environmental stressors in crayfish
3. Examination of the autonomic response during exercise in crayfish
4. Associative learning paradigms for crayfish and anticipation of stress
5. Comparative studies of chemosensory capabilities due to reliance on different primary sensory modalities
6. Examination of the role of carbon dioxide as an environmental cue for a potentially toxic environment in crayfish
7. Mechanistic action of carbon dioxide on neuronal communication and function at the neuromuscular junction of skeletal muscles, as well as the effect on the neural circuitry.

Collaborative Research Projects

1. Parasite-related effects of Acanthocephalus dirus on the CNS through manipulation of serotonin and dopamine levels of its intermediate host, Caecidotea intermedius (Isopoda) ; Dr. Timothy Sparkes, DePaul University, Department of Biological Sciences, Chicago, IL.
2. Crustacean associative learning and memory.  Dr. Zhana P. Shuranova, Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow Russia.

Bierbower S.M., Sparkes T.C. (2007)  Parasite-related success in an intermediate host, Caecidotea intermedius (Isopoda): effects of male behavior and reproductive physiology.  J. Parasitol. 93 (3): 445-449.  

Sparkes, T.C., Bierbower, S.M., Mormann, K., Kopp, D. and Murphy, A.D.  Serotonin and dopamine levels in the CNS of the intermediate host Caecidotea intermedius (Isopoda):  Implications for acanthocelphalan-related host modification.  (In Review)