Nuclei of the Lateral Lemniscus: Anatomy and Physiology
The axons of neurons in CN and SOC ascend to the midbrain on each side in LL (see Fig. 1). Embedded within the fibers of LL is a band of cells, extending from the region immediately rostral to LSO to just ventral to IC. Traditionally, two nuclear groups have been distinguished within this cell band — a dorsal nucleus (DNLL) ventral and slightly lateral and caudal to IC, and a ventral nucleus (VNLL) extending from rostral SOC to DNLL (e.g., Berman 1968; Ramon y Cajal 1909; Stotler 1953; Taber 1961). Within the traditionally defined VNLL a number of regions can be distinguished on cytoarchitectonic grounds (Adams 1979; van Noort 1969; Roth et al. 1978; Taber 1961). Although there is a considerable overlap between these regions, the cytoarchitectonic differences, in conjunction with differences in connections, have prompted a redefinition of the cell groups ventral to DNLL. In the revised scheme, VNLL comprises a ventral region of oval cells and a vertically extended region of multipolar and horizontal cells — termed by Adams (1979) the ventral and medial zones of VNLL. The region of sparsely distributed multipolar cells between VNLL so defined and DNLL — termed by Adams (1979) the dorsal zone of VNLL — is designated the intermediate nucleus (INLL; Brunso-Bechtold et al. 1981; Glendenning et al. 1981; Kane and Barone 1980). Hypertrophy of INLL and VNLL has been described in some mammals with ultrasonic hearing, viz., the dolphin and some bats (Zook and Casseday 1982a; Zvorykin 1964).
KeywordsOnset Response Medial Geniculate Body Ventral Cochlear Nucleus Multipolar Cell Lateral Lemniscus
Unable to display preview. Download preview PDF.