Principal Investigator: Timothy C. Tricas, Doctoral Student: Karen P. Maruska
Neuron cell bodies that produce the neuropeptide hormones gonadotropin-releasing hormone (GnRH) and arginine vasotocin (AVT) are regionally distributed in the vertebrate brain and known to be important regulators of reproductive development and behavior. However, the extensive projections of axons throughout the brain indicate additional functions not directly related to pituitary hormone release and reproduction. The sensory neuromodulation hypothesis proposes that these peptides affect sensory processing of sexual stimuli and integrate sensory input with motor activities related to social behaviors, but few studies have directly tested this hypothesis. This project will test the sensory neuromodulation hypothesis using the Hawaiian sergeant major fish, a common benthic-spawning reef species. Social behaviors and the related acoustic stimuli produced by males and females during reproduction will be characterized, and the importance of their auditory and lateral line senses in these natural behaviors determined. Neurophysiological and microinjection experiments will then directly test the effects of GnRH and AVT on the sensitivity and processing of these stimuli in the central nervous system. This integrative study will present the first test of the sensory neuromodulation hypothesis in the auditory and lateral line sensory systems of fishes, and provide critical information for determining the function of neuropeptide modulation of hair-cell based sensory mechanisms in vertebrates. Undergraduates will be trained in behavior and neurobiology research techniques, and secondary school students from outreach programs will be involved to encourage their pursuit of careers in science.
