Washington University in St. Louis
Campus Box 1137
One Brookings Drive
St. Louis, MO 63130-4899
The auditory system consists of the ascending and descending (corticofugal) systems. Nobuo Suga has recently been exploring the functional role of the corticofugal system in hearing, because the corticofugal system has been poorly studied over the last 40 years and because his lab has found that it is involved in the adjustment and improvement of auditory signal processing. Suga has been testing his hypothesis that the corticofugal system reorganizes the central auditory system for a sound that is frequently perceived by an animal, that the reorganization is augmented as the sound becomes behaviorally relevant to the animal through associative learning, and that not only the auditory cortex, but also non-auditory sensory cortices, the amygdala, and the cholinergic basal forebrain are involved in this augmentation. Photo caption: The big brown bat, Eptesicus fuscus, photo by Dr. Steven Dear
Suga, N. and Ma, X. (2003) Multiparametric corticofugal modulation and plasticity in the auditory system. Nature Rev. Neurosci. 4: 783-794.
Xiao, Z. and Suga, N. (2004) Reorganization of the auditory cortex specialized for echo-delay processing in the mustached bat. Proc. Natl. Acad. Sci. USA 101: 1769-1774.
Xiao, Z. and Suga, N. (2005) Asymmetry in corticofugal modulation of frequency-tuning in mustached bat auditory system. Proc. Natl. Acad. Sci. 102: 19162-19167.
Ma, X. and Suga, N. (2005) Long-term plasticity evoked by electric stimulation and acetylcholine applied to the auditory cortex. Proc. Natl. Acad. Sci. 102: 9335-9340.
Ji, W., Suga, N. and Gao, E. (2005) Effects of agonists and antagonists of NMDA and ACh receptors on plasticity of bat auditory system elicited by fear conditioning. J. Neurophysiol. 94: 1199-1211.