Associate Professor, BCMB
Office : WLS, F-215: (865-974-3069)
Lab: WLS, A-203: (865-974-3980)
Ph.D. Neuroscience, University of Illinois at Champaign-Urbana
Our research focuses on identifying neural mechanisms mediating the localization and recognition of biologically relevant sounds. We are currently engaged in three distinct lines of research. The first is a collaborative project with the Department of Electrical Engineering and Computer Science to identify neural circuits engaged in detecting and tracking moving sound sources. Much progress has been made in identifying mechanisms underlying static sound localization, however, little is known about how the auditory system determines the direction and speed of moving sound sources. To address this issue we are using vertically aligned carbon nanofiber arrays implanted chronically in the brain of hamsters to record simultaneously the activity of large populations of auditory neurons evoked by moving sound sources. The array interfaces with a custom-designed amplifier that digitizes and transmits wirelessly, recorded electrical activity to a receiver for subsequent analysis. Thus, we are in the unique position of being able to directly monitor neural activity in the brain of a behaving, untethered animal; a powerful technique that is expected to reveal key elements of brain design and function. A second project, carried out in conjunction with the Department of Audiology & Speech Pathology, is aimed at understanding the mechanism that describes the relationship between the neural representation of speech cues and how such cues are degraded by cochlear damage or hearing aid sound processing. Our study employs both humans and animals (hamsters). To accomplish our goals we utilize signal processing algorithms, psychoacoustics, electrophysiological techniques and neural modeling. Finally, we are using fiddler crabs as a model system for investigating the neural mechanisms underlying the recognition and localization of vibrational signals used for inter- and intraspecific communication. Vibrational communication is prevalent throughout the animal kingdom yet little is known about the perception and processing of vibrational signals in the nervous system. Ongoing research utilizes intracellular recording and staining techniques to address this issue.
Fuzessery ZM, Wenstrup JJ, Hall JC and Leroy S (2003) The role of inhibition in shaping response latency in the inferior colliculus. JARO. 4: 60 – 73.
Zheng W and Hall JC (2000) GABAergic inhibition shapes frequency tuning and modifies response properties in the superior olivary nucleus of the leopard frog. J. Comp. Physiol. A. 186: 661 – 671.
Hall JC (1999) GABAergic inhibition shapes frequency tuning and modifies response properties in the auditory midbrain of the leopard frog. J. Comp. Physiol. A. 185: 479 – 491.
Fuzessery ZM and Hall JC (1999) Sound duration selectivity in the pallid bat inferior colliculus. Hearing Res. 137: 137 – 154.
Fuzessery ZM and Hall JC (1996) Role of GABA in shaping frequency tuning and creating FM sweep selectivity in the inferior colliculus. J. Neurophysiol. 76(2): 1059 – 1073.
Hall JC and Bunker MC (1994) Acetycholinesterase staining in the auditory brainstem nuclei of the northern leopard frog, Rana pipiens. Neurosci. Letters 182: 222 – 226.