DEBRA WOOD, PHD
Assistant Professor of Biology
Research Interests
Dr. Wood's research interests center on how rhythmic behaviors are generated by animals. Animals must make adaptative behavioral choices depending upon environmental and internal cues they receive. Further, animals exhibit flexibility in ongoing patterns of behavior that are necessary to maintain appropriate responses to changing conditions. For example, horses must choose a distinct gait pattern as well as alter its individual steps in a chosen gait to run effectively. Our lab is investigating both cellular and behavioral aspects of neural and mechanical correlates underlying fluidity of motor pattern generation. These kinds of similar but yet distinct motor pattern have been shown to be produced by multi-functional neural networks and not by circuits of neurons 'dedicated' to a particular behavior. Neuromodulation is one of the primary mechanisms used by nervous systems to create flexibility in the pattern generating networks of neurons. We study neuromodulation as it occurs via release of neurotransmitters and hormones that have potential to functionally 'rewire' a circuit of neurons, and thus, altering the motor pattern produced by pattern generating neural circuits. Modulation of neural networks to allow variation in motor outflows is a phenomenon common to systems as diverse as generation of locomotion by the mammalian spinal cord and less complex systems such as those responsible for walking, feeding, or flying in insects and slugs. These less complex nervous systems provide an opportunity to ask questions at a mechanistic level not often amenable in larger systems.
 Our lab uses the stomatogastric nervous system (STNS) of a crab (Cancer borealis) as a model system to study the generation of rhythmicity. The STNS contributes to neural control of swallowing, chewing, and filtering of food through the digestive system of the crab. Because there are only 25 neurons that make up the primary pattern generating circuits for these behaviors, the activity of all types of neurons in the network may be monitored simultaneously using both intracellular and extracellular electrophysiology techniques. Past work has focused on the influences of co- transmitters released onto this rhythmic network, and the role of rhythmic release of modulators by presynaptic inputs that select and coordinate of motor output. Future work will focus on using electrophysiology combined with fluorescence microscopy techniques to investigate the role of second messenger systems in the processing of signals received via identified co-transmitters released from an identified pre-synaptic input. We are also developing techniques to examine the selection of distinct feeding behaviors in freely moving crabs so that motor pattern selection by the nervous system from multifunctional network and biomechanical influences on behavior will be better understood in behavioral context.
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