Abstract
Mammalian inferior colliculus(IC) is an integrative auditory processing center of the midbrain. IC has complex neural circuits and is majorly devided into two regions: central nucleus (CIC, tonotopic region) and dorsal and external cortices (non-tonotopic region). By the focal injection of neuronal tracers into IC and GAD immunohistochemical technique, we investivated the characteristics of the local circuits of IC. The results show that the left and right ICs have characteristic connections; 1) the left and right CIC-CIC, cortices-cortices have strong connections(about 70% of total connections). 2) the CIC-CIC connections are symmetric and they are majorly excitatory (98%). We further analyzed the characteristics of the labeled local circuits by in vivo and in vitro electrophysiological techniques. [J Physiol Sci. 2006;56 Suppl:S186]
