Anatomic Evidence of a Three-Dimensional Mosaic Pattern of Tonotopic Organization in the Ventral Complex of the Lateral Lemniscus in Cat

摘要: The ventral complex of the lateral lemniscus (VCLL, i.e., and intermediate nuclei) is composed cells embedded in fibers lemniscus. These are involved processing monaural information receive input from collaterals ascending to inferior colliculus. Whereas tonotopic organization a feature all other nuclei auditory system, this functional principle debated VCLL. We have made focal injections tracer biotinylated dextran amine into different frequency band representations colliculus cat. Retrogradely labeled terminal (collaterals efferent local axons lemniscal fibers) were found ipsilateral spatial distribution labeling was analyzed using three-dimensional (3-D) reconstruction computer graphical visualization techniques. A topographic found. In cases, distributed multiple clusters throughout dorsoventral extent shape, size, location suggest an interdigitation assigned frequency-band representations. But overall mediolateral gradient observed, with high frequencies represented medially lower progressively more laterally. conclude that may represent discontinuous compartments as counterpart continuous laminar remaining nuclei. 3-D orderly mosaic pattern indicates VCLL preserves spectral decomposition originated cochlea way facilitates across-frequency integration.