Alligators
Amy Streets
Animals evolved nervous systems that can detect specific physical features of their environment. In vertebrates, the cochlear nuclei of the auditory brainstem have evolved unique characteristics that encode cues for the localization of sounds in space. The circuitry and connections of these nuclei have been well studied in mammals and birds. I am interested in how this circuit has evolved, and what features are ancestral or derived. Little is known about the cochlear nuclei of the crocodilians. This is a particularly interesting group to study because crocodilians have not changed morphologically in millions of years but also together with birds they form the group archosauria. Further, crocodilians, including the Alligator mississippiensis, live in acoustically challenging environments and have well developed vocalization repertoires. In this proposal I will examine the projections of the auditory nerve to the auditory brainstem nuclei that are responsible for computing sound source location. Since these nuclei have been shown to be present in all archosaurs, my results will provide insights into the evolution of sound localization. Any differences or similarities in connectivity may shed light on the ancestral condition of the group.
I am also using behavior to determine the ability of juvenile alligators to localize a sound source.
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